Ethereum's Transactions, Validation, and Upgrades BDC Practice Questions (Page 4)

Questions 16–20

1. 16foundation · easy

   What happens to unused gas after a transaction is executed?

   • AIt is given to the miner
   • BIt is burned
   • CIt is refunded to the sender
   • DIt is added to the next block's gas limit
   Reveal Solution Discussion Select an answer first
2. 17application · medium

   A developer is explaining the difference between a regular transaction and an internal transaction (message call). Which statement is accurate?

   • AInternal transactions have their own nonce and gas limit.
   • BInternal transactions are signed by the sender and broadcast to the network.
   • CInternal transactions are included in the block as separate entries.
   • DInternal transactions are created by smart contracts and do not require a separate signature.
   Reveal Solution Discussion Select an answer first
4. 18foundation · easy

   Which Ethereum upgrade introduced the concept of the base fee and burning mechanism?

   • ABerlin
   • BLondon
   • CIstanbul
   • DConstantinople
   Reveal Solution Discussion Select an answer first
5. 19expert · hard

   A developer is reviewing the history of Ethereum upgrades and wants to understand the impact of the Istanbul upgrade on transaction processing. Which statement is accurate?

   • AIstanbul changed the gas cost of certain opcodes and improved denial-of-service resilience.
   • BIstanbul increased the block gas limit to allow more transactions per block.
   • CIstanbul introduced EIP-1559, which changed the fee market to include a base fee and priority fee.
   • DIstanbul introduced the beacon chain and Proof of Stake consensus.
   Reveal Solution Discussion Select an answer first
6. 20application · medium

   A node operator is troubleshooting why a newly received block was rejected. The block header is valid, and the PoS attestations are correct. What other validation must the node perform before accepting the block?

   • AEnsure the block's gas limit is exactly equal to the parent block's gas limit.
   • BCheck that the block's timestamp is greater than the parent block's timestamp plus 10 seconds.
   • CConfirm that the block proposer is the one with the highest stake in the network.
   • DVerify that each transaction's signature is valid and the sender has sufficient balance.
   Reveal Solution Discussion Select an answer first