# Blockchain and its Applications | Week 3

Session: JAN-APR 2024

Course Name: Blockchain and its Applications

#### These are Blockchain and its Applications Assignment 3 Answers

Q1. Inspect and explore block #828070 using this link to solve the below question. What is the hash of the previous block for Bitcoin block #828070?

Q2. Which of the following Python scripts will generate a TRUE outcome?
a. scriptSig: scriptPubKey: OP_DUP OP_HASH256 OP_EQUAL OP_VERIFY OP_CHECKSIG
b. scriptSig: scriptPubKey: OP_HASH160 OP_EQUAL
c. scriptSig: scriptPubKey: OP_EQUALVERIFY
d. scriptSig: scriptPubKey: OP_CHECKSIG

Answer: c. scriptSig: scriptPubKey: OP_EQUALVERIFY

These are Blockchain and its Applications Assignment 3 Answers

Q3. In the Bitcoin block header, the block identifier is calculated
a. Using SHA256 on the current block header
b. Using Double SHA256 on the previous block hash
c. Using Double SHA256 on the Difficulty bits
d. Using Double SHA256 on the current block header

Answer: d. Using Double SHA256 on the current block header

Q4. If the six-byte difficulty bits in the hexadecimal form are 0x1a05f20881ab, and the target value is calculated using X* 2^(Y), what are the values for X and Y respectively?
a. X = 0x5f20881ab, Y = 0x1a
b. X = 0x1a05f2, Y = 0x0881ab
c. X = 0x1a05f2, Y = 0x18
d. X = 0x5f20881ab, Y = 0x1a0

Answer: a. X = 0x5f20881ab, Y = 0x1a

These are Blockchain and its Applications Assignment 3 Answers

Q5. DLT can be used to maintain financial information only.
a. False
b. True

Q6. Which one of the following opcodes is needed to remove the second-to-top stack item?
a. OP_DELETE
b. OP_2POP
c. OP_DEQUE
d. OP_NIP

These are Blockchain and its Applications Assignment 3 Answers

Q7. Bitcoin Scripting Language:
a. Not Turing Complete
b. Supports Cryptography
C. Queue Based
d. Supports infinite time/memory

Q8. Permissioned blockchain is regarded as more secure than open blockchain as the participants are known beforehand and pre-authenticated.
a. True
b. False

These are Blockchain and its Applications Assignment 3 Answers

Q9. What is nonce?
a. The transaction ID number
b. A miner ASIC chip array
C. The generator point used in elliptic curve cryptography
d. The number miners run through to generate a correct hash

Answer: d. The number miners run through to generate a correct hash

Q10. Which of these fields is present in a Bitcoin block summary?
a. Nonce
b. Gas Used
c. Gas Limit
d. Private Key of the Sender

These are Blockchain and its Applications Assignment 3 Answers

More Solutions of Blockchain and its Applications: Click Here

Session: JAN-APR 2022

Course Name: Blockchain and its Applications

#### Q1. Bitcoin mining is performed bya. Miner nodesb. Internal Nodesc. External Nodesd. Orphan Nodes

Answer: a. Miner nodes

Q2. DLT can be used to maintain financial information only.
a. False
b. True

These are Blockchain and its Applications Assignment 3 Answers

Q3. Which of the following is/are true for basic PoW consensus?
a. Miner needs to propose a block
b. The miner needs to solve a puzzle to obtain target block hash
c. The puzzle solution is added as proof for leadership
d. Successful miner node is rewarded

Answer: a, b, c, d

Q4. Bitcoin Scripting Language:
a. Not Turing Complete
b. Supports Cryptography
c. Stack Based
d. Supports infinite time/memory

Answer: a, b, c

These are Blockchain and its Applications Assignment 3 Answers

Q5. Permissioned blockchain is regarded as more secure than open blockchain as the participants are known beforehand and pre-authenticated.
a. True
b. False

Q6. What is nonce?
a. The transaction id number
b. A miners ASIC chip array
c. The generator point used in elliptic curve cryptography
d. The number miners run through to generate a correct hash

Answer: d. The number miners run through to generate a correct hash

These are Blockchain and its Applications Assignment 3 Answers

Q7. Which one of the following opcodes is needed to remove the top stack item.
a. OP POP
b. OP_DEQUE
c. OP DROP
d. OP DELETE

Answer: c. OP DROP

Q8. Which of these fields is present in a Bitcoin block summary?
a. Difficulty
b. Gas Used
c. Gas Limit
d. Private Key of the Sender

These are Blockchain and its Applications Assignment 3 Answers

Q9. If the four-byte difficulty bits in hex form are 0x1b0404cb, and the target value is calculated using X* 2^(Y), what is the values for X and Y respectively,
a. X = 0x0404cb, Y = 0x1b
b. X = 0x0404cb, Y = 0x18
c. X = 0x0404cb, Y = 0xc0
d. X = 0x1b0404, Y = 0xcb

Answer: c. X = 0x0404cb, Y = 0xc0

Q10. In bitcoin block header, the block identifier is calculated
a. Using SHA256 on the current block header
b. Using Double SHA256 on the previous block hash
c. Using Double SHA256 on the Difficulty bits
d. Using Double SHA256 on the current block header

Answer: d. Using Double SHA256 on the current block header

These are Blockchain and its Applications Assignment 3 Answers

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