Ethereum Developer Ethereum Virtual Machine (EVM) and Gas Optimization 2

Question 1

What is 'gas' in the context of the Ethereum network?

Accepted Answer

A unit measuring the computational work required to execute operations

Answer

The cryptocurrency used to reward validators

Answer

The total amount of Ether held in a contract

Answer

The number of pending transactions in the mempool

Question 2

What is the approximate gas cost of writing to a new (zero-to-nonzero) storage slot using SSTORE?

Accepted Answer

20,000 gas

Answer

200 gas

Answer

2,100 gas

Answer

200,000 gas

Question 3

After EIP-1559, what happens to the base fee portion of a transaction fee?

Accepted Answer

It is burned and permanently removed from circulation

Answer

It is paid to validators as a block reward

Answer

It is sent to the Ethereum Foundation treasury

Answer

It is redistributed proportionally to all stakers

Question 4

In Ethereum's EIP-1559 fee model, what is the 'priority fee' (tip)?

Accepted Answer

An optional fee paid directly to validators to incentivize faster inclusion

Answer

A mandatory fee for smart contract deployment

Answer

A fee charged when a transaction reverts

Answer

A fee paid to the network for state storage

Question 5

What triggers a gas refund in Ethereum smart contracts?

Accepted Answer

When a storage slot is cleared by writing zero to a non-zero value

Answer

When a transaction completes without errors

Answer

When a function is declared as 'pure'

Answer

When a contract calls another contract successfully

Question 6

What happens when a transaction runs 'out of gas' in Ethereum?

Accepted Answer

All state changes revert and the consumed gas is not refunded

Answer

The transaction is retried automatically with more gas

Answer

The transaction is queued until gas prices drop

Answer

Only the failed opcode is skipped and execution continues

Question 7

How much gas does a standard ETH transfer (no data, no contract) cost?

Accepted Answer

21,000 gas

Answer

5,000 gas

Answer

50,000 gas

Answer

100,000 gas