CCE Smart Contracts and Ethereum 5

Question 1

What does EIP-1559 change about Ethereum's transaction fee mechanism?

Accepted Answer

It introduces a base fee that is burned and a priority tip paid to validators

Answer

It eliminates gas entirely and replaces it with a flat fee

Answer

It allows miners to set gas prices freely without user input

Answer

It caps the maximum gas per block at 15 million permanently

Question 2

What is the Ethereum Virtual Machine (EVM) stack depth limit?

Accepted Answer

1024 levels

Answer

256 levels

Answer

512 levels

Answer

2048 levels

Question 3

Which Solidity keyword prevents a function from modifying contract state?

Accepted Answer

view

Answer

payable

Answer

internal

Answer

immutable

Question 4

What is 'gas stipend' in Ethereum, and how much is it?

Accepted Answer

A small amount of gas (2,300) automatically forwarded when a contract sends Ether via transfer()

Answer

A bonus given to miners for including a transaction, worth 21,000 gas

Answer

The minimum gas required to deploy any smart contract, set at 32,000 gas

Answer

A refund issued when a SELFDESTRUCT opcode frees storage, worth 15,000 gas

Question 5

In Ethereum's Proof of Stake, what is 'slashing'?

Accepted Answer

Penalizing validators who double-sign or vote for conflicting blocks by destroying part of their stake

Answer

Reducing the block reward by half on a scheduled basis

Answer

Cutting transaction fees when network congestion drops below a threshold

Answer

Removing inactive validators from the validator set after a timeout

Question 6

What is a 'Merkle Patricia Trie' used for in Ethereum?

Accepted Answer

Efficiently encoding and verifying account balances, storage, and transaction data in each block

Answer

Storing validator BLS public keys for signature aggregation

Answer

Compressing smart contract bytecode before storing it on-chain

Answer

Tracking the chronological order of pending mempool transactions

Question 7

What distinguishes an EOA (Externally Owned Account) from a contract account in Ethereum?

Accepted Answer

EOAs are controlled by a private key and have no code; contract accounts have deployed bytecode and are controlled by their logic

Answer

EOAs can hold Ether but not ERC-20 tokens; contract accounts can hold both

Answer

EOAs are created by miners; contract accounts are created by the Ethereum Foundation

Answer

EOAs pay no gas fees; contract accounts pay gas for every internal call