Proof of Work (PoW) and Its Variations BDC Practice Questions (Page 7)

Questions 31–35

1. 31application · medium

   A non-profit organization wants to raise awareness about the environmental impact of blockchain. They are preparing a report comparing consensus mechanisms. Which statement is most accurate?

   • APoW consumes more energy than PoS because it requires solving computationally intensive puzzles, while PoS selects validators based on stake.
   • BPoW is more energy-efficient than PoS because it uses specialized hardware that is optimized for hashing.
   • CPoA consumes more energy than PoW because it requires a larger number of validators.
   • DPoW and PoS consume similar amounts of energy because both require validators to run full nodes.
   Reveal Solution Discussion Select an answer first
2. 32application · medium

   A developer is debugging a custom PoW implementation. The code sets a target value and requires the block hash to be less than the target. The current target is 0x0000FFFF... (with many leading zeros). The developer wants to make the puzzle harder. What should the developer do?

   • AIncrease the target value so that more hashes satisfy the condition.
   • BAdd more transactions to the block to increase the hash computation time.
   • CDecrease the target value so that fewer hashes satisfy the condition.
   • DChange the hash function from SHA-256 to SHA-512.
   Reveal Solution Discussion Select an answer first
4. 33foundation · easy

   Which of the following is a proposed mitigation for the environmental impact of Proof of Work?

   • AUsing renewable energy sources to power mining operations.
   • BUsing more efficient mining hardware to reduce the number of miners.
   • CReducing the difficulty adjustment frequency.
   • DIncreasing the block size to reduce the number of blocks needed.
   Reveal Solution Discussion Select an answer first
5. 34foundation · easy

   What is the main difference between Ethash and RandomX as Proof of Work algorithms?

   • AEthash is a pure CPU algorithm, while RandomX is GPU-only.
   • BEthash uses SHA-256, while RandomX uses scrypt.
   • CEthash is used by Bitcoin, while RandomX is used by Litecoin.
   • DEthash is memory-hard to limit ASIC efficiency, while RandomX is designed to be CPU-friendly and ASIC-resistant.
   Reveal Solution Discussion Select an answer first
6. 35application · medium

   A private enterprise blockchain needs to process transactions quickly and with minimal energy overhead. The consortium members are known and trusted. Which consensus mechanism is most appropriate?

   • AProof of Stake, because it requires validators to lock up coins, which is easy for enterprises.
   • BProof of Authority, because it uses a small set of approved validators, enabling fast block times and low energy use.
   • CProof of Work, because it provides the highest level of security.
   • DDelegated Proof of Stake, because it allows coin holders to vote for delegates, ensuring decentralization.
   Reveal Solution Discussion Select an answer first