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Exam BTA Certified Blockchain Solution Architect
Number CBSA
File Name Blockchain.CBSA.PrepAway.2019-04-01.67q.vcex
Size 253 KB
Posted Apr 01, 2019
Download Blockchain.CBSA.PrepAway.2019-04-01.67q.vcex

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Demo Questions

Question 1

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 2

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 3

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 4

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 5

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 6

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 7

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 8

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 9

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 10

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 11

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 12

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 13

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 14

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 15

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 16

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 17

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 18

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 19

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 20

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 21

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 22

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 23

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 24

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 25

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 26

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 27

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 28

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 29

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 30

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 31

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 32

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 33

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 34

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 35

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 36

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 37

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 38

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 39

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 40

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 41

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 42

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 43

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 44

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 45

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 46

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 47

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 48

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 49

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 50

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 51

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 52

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 53

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 54

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 55

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 56

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 57

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 58

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 59

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 60

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 61

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 62

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 63

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 64

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 65

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 66

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 67

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 68

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 69

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 70

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 71

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 72

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 73

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 74

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 75

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 76

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 77

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 78

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 79

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 80

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 81

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 82

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 83

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 84

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 85

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 86

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 87

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 88

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 89

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 90

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 91

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 92

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 93

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 94

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 95

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 96

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 97

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 98

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 99

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 100

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 101

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 102

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 103

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 104

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 105

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 106

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 107

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 108

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 109

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 110

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 111

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 112

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 113

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 114

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 115

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 116

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 117

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 118

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 119

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 120

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 121

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 122

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 123

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 124

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 125

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 126

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 127

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 128

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 129

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 130

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 131

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 132

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 133

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 134

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 135

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 136

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 137

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 138

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 139

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 140

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 141

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 142

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 143

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 144

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 145

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 146

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 147

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 148

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 149

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 150

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 151

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 152

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 153

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 154

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 155

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 156

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 157

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 158

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 159

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 160

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 161

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 162

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 163

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 164

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 165

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 166

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 167

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 168

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 169

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 170

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 171

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 172

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 173

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 174

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 175

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 176

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 177

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 178

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 179

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 180

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 181

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 182

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 183

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 184

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 185

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 186

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 187

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 188

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 189

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 190

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 191

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 192

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 193

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 194

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 195

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 196

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 197

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 198

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 199

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 200

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 201

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 202

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 203

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 204

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 205

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 206

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 207

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 208

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 209

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 210

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 211

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 212

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 213

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 214

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 215

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 216

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 217

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 218

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 219

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 220

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 221

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 222

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 223

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 224

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 225

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 226

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 227

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 228

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 229

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 230

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 231

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 232

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 233

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 234

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 235

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 236

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 237

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 238

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 239

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 240

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 241

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 242

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 243

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 244

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 245

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 246

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 247

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 248

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 249

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 250

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 251

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 252

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 253

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 254

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 255

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 256

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 257

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 258

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 259

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 260

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 261

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 262

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 263

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 264

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 265

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 266

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 267

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 268

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 269

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 270

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 271

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 272

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 273

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 274

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 275

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 276

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 277

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 278

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 279

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 280

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 281

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 282

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 283

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 284

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 285

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 286

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 287

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 288

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 289

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 290

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 291

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 292

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 293

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 294

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 295

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 296

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 297

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 298

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 299

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 300

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 301

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 302

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 303

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 304

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 305

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 306

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 307

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 308

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 309

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 310

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 311

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 312

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 313

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 314

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 315

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 316

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 317

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 318

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 319

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 320

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 321

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 322

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 323

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 324

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 325

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 326

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 327

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 328

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 329

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 330

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 331

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 332

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 333

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 334

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 335

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 336

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 337

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 338

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 339

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 340

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 341

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 342

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 343

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 344

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 345

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 346

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 347

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 348

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 349

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 350

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 351

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 352

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 353

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 354

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 355

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 356

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 357

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 358

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 359

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 360

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 361

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 362

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 363

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 364

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 365

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 366

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 367

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 368

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 369

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 370

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 371

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 372

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 373

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 374

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 375

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 376

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 377

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 378

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 379

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 380

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 381

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 382

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 383

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 384

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 385

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 386

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 387

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 388

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 389

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 390

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 391

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 392

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 393

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 394

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 395

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 396

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 397

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 398

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 399

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 400

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 401

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 402

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 403

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 404

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 405

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 406

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 407

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 408

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 409

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 410

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 411

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 412

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 413

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 414

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 415

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 416

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 417

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 418

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 419

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 420

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 421

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 422

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 423

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 424

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 425

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 426

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 427

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 428

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 429

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 430

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 431

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 432

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 433

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 434

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 435

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 436

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 437

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 438

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 439

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 440

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 441

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 442

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 443

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 444

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 445

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 446

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 447

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 448

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 449

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 450

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 451

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 452

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 453

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 454

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 455

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 456

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 457

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 458

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 459

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 460

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 461

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 462

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 463

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 464

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 465

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 466

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 467

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 468

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 469

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 470

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 471

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 472

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 473

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 474

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 475

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 476

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 477

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 478

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 479

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 480

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 481

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 482

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 483

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 484

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 485

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 486

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 487

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 488

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 489

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 490

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 491

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 492

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 493

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 494

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 495

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 496

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 497

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 498

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 499

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 500

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 501

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 502

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 503

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 504

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 505

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 506

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 507

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 508

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 509

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 510

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 511

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read



Question 512

Your customer is an enterprise that is focused on financial sectors. What type of blockchain would this customer likely want specified for their enterprise? 


  1. Permissionless
  2. Decentralized
  3. Hybrid
  4. Permissioned
Correct answer: D
Explanation:
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Sometimes referred to as “private” blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 513

Ethereum is considered to be a ______________type of blockchain.


  1. Permissionless
  2. Permission Based
  3. Hybrid
  4. Private
Correct answer: A
Explanation:
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095
Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.  
Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095



Question 514

Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda. 
What is the best answer?


  1. R3 Corda is a pluggable blockchain and allows the enterprise flexibility
  2. R3 Corda is a byzantine fault tolerant blokchain
  3. R3 Corda is a proof of stake based blockchain
  4. R3 Corda is a proof of work based blockchain
Correct answer: A
Explanation:
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.
Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom – and took this opportunity – to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.



Question 515

Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.


  1. NSA is spying on us so what’s it matters.
  2. Depends on input
  3. False
  4. True
Correct answer: D
Explanation:
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 516

In the Ethereum EVM there are two types of memory areas. (Select two.)


  1. Storage
  2. Database
  3. Memory
  4. Persistent
  5. Ephemeral
Correct answer: AC
Explanation:
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine
Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereum-virtual-machine



Question 517

What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)


  1. Energy efficient in regards to that it could consume for electricity as compared to PoW
  2. Faster Hashing algorithms
  3. No need for expensive compared to POW
  4. Faster validations compared to POW
  5. Better blockchain security compared to POW
Correct answer: ACD
Explanation:
This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10
This eliminates the below challenges from PoW and believed to have an advantage. 
No need of expensive hardware (a normal laptop or computer running the respective coin’s Validator client will do as long as your laptop or computer is online) Energy efficient as it won’t consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for “forging” and earn the transaction fee Faster validations  
Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stake-e1eee1420b10



Question 518

Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.


  1. TRUE
  2. FALSE
Correct answer: B
Explanation:
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition Reference: https://www.trymining.com/pages/asic-vs-gpu 
ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition 
Reference: https://www.trymining.com/pages/asic-vs-gpu 



Question 519

Which of the following would NOT be true about what a smart contract gives your organization?


  1. Accuracy
  2. Savings
  3. Autonomy
  4. Trust
  5. Legal Assurance
Correct answer: E
Explanation:
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  Reference: https://blockgeeks.com/guides/smart-contracts/
Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here  
Reference: https://blockgeeks.com/guides/smart-contracts/



Question 520

The ____________of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as ________nodes. Each node is simply a cryptographic hash of a transaction. 
  
In the above diagram, Transaction A,B, C,C from the leaves of the tree. Select one.


  1. Root, Hash
  2. Root, Leaf Nodes
  3. Has, Root nodes
  4. Leaf nodes, Root
  5. Leaf Nodes, Root
Correct answer: B
Explanation:
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2
The root of the tree is the topmost node and hence this tree is represented upside down. The bottommost nodes are called as leaf nodes. Each node is simply a cryptographic hash of a transaction. In the above diagram, Transaction A,B,C,C form the leaves of the tree.  
Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2



Question 521

What are two challenges with using a Proof of Work algorithm? (Select two.)


  1. Mining pools not allowed
  2. Difficulty rate goes done every year.
  3. Expensive
  4. Power Intensive
Correct answer: CD
Explanation:
Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read
Reference: http://www.hl.co.uk/news/2018/2/16/