Blockchain and its Applications | Week 5

Session: JAN-APR 2024

Course Name: Blockchain and its Applications

Course Link: Click Here

For answers or latest updates join our telegram channel: Click here to join

These are Blockchain and its Applications Assignment 5 Answers


Q1. The height of the block is the in the chain between it and the genesis block.
a. Metafiles
b. Hash
c. Log size
d. Number of blocks

Answer: d. Number of blocks


Q2. What is the CLI command used to send ethers after the nodes have been initialized?
a. eth.submitTransaction()
b. eth.sendTransaction()
c. eth.sendIBANTransaction()
d. eth.sendRawTransaction()

Answer: b. eth.sendTransaction()


These are Blockchain and its Applications Assignment 5 Answers


Q3. Which of the following syntax is correct to write data in a smart contract using solidity
a. myContract.methods.store(“55”).set()
b. myContract.methods.write(“55”).send()
c. myContract.methods.store(“55”).send()
d. myContract.methods.write(“55”).set()

Answer: c. myContract.methods.store(“55”).send()


Q4. What is the limitation of using the consensus algorithm Proof of Work (POW)?
a. A lot of mining power is wasted as only one gets success in mining at a time
b. PoW is used for permissioned blockchain
c. It is used for blockchain mining
d. High transaction throughput

Answer: a. A lot of mining power is wasted as only one gets success in mining at a time


These are Blockchain and its Applications Assignment 5 Answers


Q5. Which statement(s) is/are true for PoS(Proof of Stake) consensus?
a. Depends on the work done by the miner
b. Depends on the amount of crypto currency the miner holds
c. Provides less protection in general
d. None of the above

Answer: b. Depends on the amount of crypto currency the miner holds


Q6. Which of the following is/are applicable for PoET (Proof of Elapsed Time) consensus
a. Each participant in the blockchain network waits a random amount of time
b. The first participant to finish becomes the follower for the new block
c. Trusted execution platform and attestation are used to verify that the proposer has really waited
d. The first participant to finish becomes the leader for the new block.

Answer: a, c, d


These are Blockchain and its Applications Assignment 5 Answers


Q7. Proof of Burn consensus algorithms also consider virtual resources or digital coins for participating in the mining activity?
a. True
b. False

Answer: a. True


Q8. 15 ether equals
a. 15X(1016) wei
b. 15X(10^18) wei
c. 15X(10^6) wei
d. 15X(10^8) wei

Answer: b. 15X(10^18) wei


These are Blockchain and its Applications Assignment 5 Answers


Q9. How an attacker could manipulate the transaction history of an existing blockchain
a. The attacker hard-forked the network and created a new blockchain network.
b. The attacker modified the smart contract and recovered the investor’s cryptocurrency.
c. The attacker gained control of more than 51% of the network’s computing power.
d. The attacker gained control of less than 49% of the network’s computing power.

Answer: c. The attacker gained control of more than 51% of the network’s computing power.


Q10. What library/API is used for smart contract deployment and invocation from Dapp?
a. Contract
b. web3
c. admin
d. eth

Answer: b. web3


For answers or latest updates join our telegram channel: Click here to join

These are Blockchain and its Applications Assignment 5 Answers

More Solutions of Blockchain and its Applications: Click Here

More Nptel Answers: Click here


Session: JAN-APR 2022

Course Name: Blockchain and its Applications

Course Link: Click Here

These are Blockchain and its Applications Assignment 5 Answers


Q1. What is the limitation of using the consensus algorithm Proof of Work (POW)?
a. A lot of mining power is wasted as only one gets success in mining at a time
b. PoW is used for permissioned blockchain
c. Low transaction throughput
d. It is used for blockchain mining

Answer: a, c


Q2. Which statement(s) is/are true for PoS(Proof of Stake) consensus?
a. Depends on the work done by the miner
b. Depends on the amount of crypto currency the miner holds
c. Provides less protection in general
d. None of the above

Answer: b. Depends on the amount of crypto currency the miner holds


These are Blockchain and its Applications Assignment 5 Answers


Q3. Which of the following is/are applicable for POET(Proof of Elapsed Time) consensus
a. Each participant in the blockchain network waits a random amount of time
b. The first participant to finish becomes the leader for the new block
c. Trusted execution platform and attestation are used to verify that the proposer has really waited
d. None of the above.

Answer: a, b, c


Q4. Proof of Burn consensus algorithms do not consider virtual resources or digital coins for participating in the mining activity?
a. True
b. False

Answer: b. False


These are Blockchain and its Applications Assignment 5 Answers


Q5. 5 ether equals
a. 5X(10^16) wei
b. 5X(10^8) wei
c. 5X(10^6) wei
d. 5X(10^18) wei

Answer: d. 5X(10^18) wei


Q6. Which of the following syntax is correct to write data in a smart contract using solidity
a. myContract.methods.store(“99”).set()
b. myContract.methods.store(“99”).send()
c. myContract.methods.write(“99”).send()
d. myContract.methods.write(“99”).set()

Answer: b. myContract.methods.store(“99”).send()


These are Blockchain and its Applications Assignment 5 Answers


Q7. How an attacker could manipulate the transaction history of a blockchain to be able to spend a token or a cryptocurrency twice.
a. The attacker hard-forked the network and created a new blockchain network.
b. The attacker modified the transaction on his node and propagated it in the network.
c. The attacker modified the smart contract and recovered the investor’s cryptocurrency.
d. The attacker gained control of more than 51% of the network’s computing power.

Answer: d. The attacker gained control of more than 51% of the network’s computing power.


Q8. What library/API is used for smart contract deployment and invocation from Dapp?
a. Contract
b. web3
c. admin
d. eth

Answer: b. web3


These are Blockchain and its Applications Assignment 5 Answers


Q9. What is the CLI command used to send ethers after the nodes have been initialized?
a. eth.submit Transaction()
b. eth.sendIBANTransaction()
c. eth.sendRawTransaction()
d. eth.sendTransaction()

Answer: d. eth.sendTransaction()


Q10. In which scenario is a smart contract the best solution to the problem?
a. A restaurant manager wants to force customers to pay for their food by transferring cryptocurrency to his wallet.
b. A chief engineer wants her smart watch to notify her when her partner enters their front door.
c. A grid company wants to automatically buy power when the price reaches a predetermined rate.
d. An insurance company wants to pay out a small vendor whenever the case manager feels it is best to do so.

Answer: c. A grid company wants to automatically buy power when the price reaches a predetermined rate.


These are Blockchain and its Applications Assignment 5 Answers

More Solutions of Blockchain and its Applications: Click Here

More NPTEL Solutions: https://progiez.com/nptel-assignment-answers/


These are Blockchain and its Applications Assignment 5 Answers
The content uploaded on this website is for reference purposes only. Please do it yourself first.