Bitcoin Blockchain Architecture and Network Transactions BFC Practice Questions (Page 8)

Questions 36–40

1. 36foundation · easy

   Why does the Bitcoin network require multiple confirmations for a transaction to be considered secure?

   • ABecause each confirmation adds a new layer of encryption to the transaction.
   • BBecause the transaction fee increases with each confirmation.
   • CBecause the sender must sign the transaction again for each confirmation.
   • DBecause each additional block makes it increasingly difficult for an attacker to reverse the transaction.
   Reveal Solution Discussion Select an answer first
2. 37foundation · easy

   What is the primary purpose of the Merkle tree in a Bitcoin block?

   • ATo order transactions by fee amount
   • BTo encrypt the transactions in the block
   • CTo store the complete transaction data in a single hash for quick retrieval
   • DTo allow efficient and secure verification of transactions in a block
   Reveal Solution Discussion Select an answer first
4. 38foundation · easy

   How is a Bitcoin transaction fee typically calculated?

   • AIt is set by the recipient and included in the output.
   • BIt is determined by the number of confirmations the transaction receives.
   • CIt is the difference between the total inputs and total outputs of the transaction.
   • DIt is a fixed percentage of the transaction amount.
   Reveal Solution Discussion Select an answer first
5. 39foundation · easy

   How does proof-of-work mining help secure the Bitcoin network?

   • AIt requires miners to hold a large amount of bitcoin as collateral.
   • BIt makes it economically infeasible for an attacker to rewrite history because they would need to redo the work of all subsequent blocks.
   • CIt encrypts all transactions so they cannot be read by unauthorized parties.
   • DIt ensures that only authorized nodes can participate in the network.
   Reveal Solution Discussion Select an answer first
6. 40expert · hard

   A blockchain analyst is studying a Bitcoin reorganization event where a block at height 700,000 was replaced by a different block at the same height. The replacement block is now part of the active chain. Which statement correctly describes what happened?

   • AThe original block was invalidated by a soft fork that changed the block reward schedule.
   • BThe replacement block was created by a miner who bribed other miners to switch chains.
   • CA longer chain containing the replacement block was mined, and the network adopted it as the valid chain.
   • DThe original block was reversed because it contained a double-spending transaction.
   Reveal Solution Discussion Select an answer first