Proof of Work (PoW) and Its Variations BDC Practice Questions (Page 4)

Questions 16–20

1. 16foundation · easy

   In Bitcoin mining, what is the role of the nonce in the block header?

   • AIt is a random number that miners change to produce different hash outputs.
   • BIt is the Merkle root of all transactions in the block.
   • CIt is the hash of the previous block.
   • DIt is the timestamp that records when the block was created.
   Reveal Solution Discussion Select an answer first
2. 17foundation · easy

   What is the fundamental difference between Proof of Work and Proof of Stake?

   • APoW is more energy-efficient than PoS.
   • BPoW is used only in private blockchains, while PoS is used only in public blockchains.
   • CPoW is faster than PoS because it does not require network consensus.
   • DPoW requires computational work to create blocks, while PoS requires validators to lock up cryptocurrency as collateral.
   Reveal Solution Discussion Select an answer first
4. 18application · medium

   A developer is configuring a private Ethereum-based PoW network for a consortium. They want to ensure that a new block is produced approximately every 15 seconds regardless of how many miners join or leave the network. Which parameter should they configure and what is its effect?

   • ASet a minimum transaction fee that is high enough to attract miners, ensuring they always produce blocks on time.
   • BSet a fixed block gas limit so that each block contains the same number of transactions, keeping block time constant.
   • CConfigure the difficulty adjustment algorithm to recalculate the target based on recent block timestamps, so the difficulty rises or falls to maintain the 15-second interval.
   • DDeploy a smart contract that automatically rewards miners for producing blocks within 15 seconds, enforcing the schedule.
   Reveal Solution Discussion Select an answer first
5. 19foundation · easy

   In Proof of Authority (PoA), what determines who can create new blocks?

   • AThe computational power a miner contributes to the network.
   • BThe amount of cryptocurrency a validator has staked.
   • CA random lottery based on the block timestamp.
   • DThe identity and reputation of pre-approved validators.
   Reveal Solution Discussion Select an answer first
6. 20application · medium

   A developer is choosing a PoW algorithm for a new cryptocurrency that aims to be mineable on ordinary consumer CPUs to encourage decentralization. Which algorithm would best align with this goal?

   • ARandomX
   • BEthash
   • CEquihash
   • DSHA-256
   Reveal Solution Discussion Select an answer first