Crypto Jobs Blockchain Fundamentals 2

Question 1

What is the primary purpose of a consensus mechanism in a blockchain network?

Accepted Answer

To agree on the valid state of the ledger without a central authority

Answer

To compress transaction data

Answer

To encrypt user wallet passwords

Answer

To set the price of the native token

Question 2

In Proof of Work, what are miners actually competing to do?

Accepted Answer

Find a hash below a target value by varying a nonce

Answer

Vote on the next block leader

Answer

Stake the most coins

Answer

Sign the most transactions

Question 3

What distinguishes Proof of Stake from Proof of Work?

Accepted Answer

Validators are chosen based on coins staked rather than computational power

Answer

It requires more electricity

Answer

It eliminates the need for any validators

Answer

It stores no transaction history

Question 4

What is a 51% attack?

Accepted Answer

When an entity controls a majority of mining or staking power and can rewrite recent blocks

Answer

When 51% of users sell their tokens

Answer

A bug affecting half the nodes

Answer

A fee increase of 51%

Question 5

What does 'immutability' mean in the context of a blockchain?

Accepted Answer

Once confirmed, recorded data is extremely difficult to alter

Answer

Blocks can be edited only by admins

Answer

The chain never adds new blocks

Answer

Tokens cannot be transferred

Question 6

Why does each block contain the hash of the previous block?

Accepted Answer

To create a tamper-evident chain linking blocks in order

Answer

To reduce storage size

Answer

To speed up transactions

Answer

To hide sender identities

Question 7

What is the role of a node in a blockchain network?

Accepted Answer

It validates and relays transactions and may keep a copy of the ledger

Answer

It only stores private keys

Answer

It exclusively mines new coins

Answer

It sets transaction fees centrally