Q1. Why does Bitcoin use proof-of-work instead of a central timestamp server?

A To slow the network down intentionally B To allow anyone to compete to order transactions without trusting a coordinator C To reduce energy consumption D To ensure blocks are always exactly 1 MB

Q2. What is the main benefit of running your own Bitcoin node?

A It guarantees faster confirmations B It lets you enforce consensus rules yourself without trusting third parties C It pays you interest on your holdings D It removes the need for backups

Q3. Why are bech32 addresses recommended over legacy formats?

A They hold more bitcoin B They reduce transaction weight and include better error detection C They are required by law D They change the consensus rules

Q4. How does batching help fee efficiency?

A By speeding up block times B By combining multiple outputs into one transaction, reducing per-payment overhead C By reducing block size limits D By eliminating the need for signatures

Q5. What is an HTLC used for in the Lightning Network?

A Storing long-term funds B Conditionally routing payments with hash preimages and timelocks C Mining new bitcoins D Encrypting wallet backups

Q6. Which practice improves on-chain privacy?

A Address reuse B Merging all UTXOs often C Using coin control to separate funds D Posting keys online

Q7. Why is Replace-By-Fee (RBF) useful?

A It cancels confirmed transactions B It lets senders bump fees on unconfirmed transactions to speed confirmation C It changes block rewards D It hides transactions

Q8. What risk does address reuse create?

A Higher fees B Lower block reward C Linkability of balances and payment history D Invalid transactions

Q9. Why do nodes reject blocks that violate consensus rules even if they have valid proof-of-work?

A To punish miners B Because proof-of-work alone is insufficient; rules prevent inflation and invalid spends C Because blocks must be under 500 kB D Because miners have no influence

Q10. What does channel liquidity affect on Lightning?

A Block reward size B Ability to route payments in a given direction C Mining difficulty D Wallet seed entropy

Q11. Why are descriptors valuable?

A They increase block size B They document script structure and derivation paths for portability C They add more fees D They replace signatures

Q12. How does CPFP accelerate a transaction?

A By deleting the parent B By spending an output with a higher-fee child that drags the parent into a block C By disabling mempools D By reducing signatures

Q13. What role do watchtowers play for Lightning users?

A They mine blocks B They monitor for revoked states and broadcast penalties if needed C They generate seeds D They replace routers

Q14. Why is progressive disclosure helpful in wallet UX?

A It hides bugs B It reveals advanced features gradually so beginners are not overwhelmed C It reduces seed length D It prevents backups

Q15. What is the purpose of a pruned node?

A To change consensus rules B To validate blocks while discarding old data to save disk space C To mint coins faster D To bypass signatures