Bitcoin and Bitcoin Blockchain Architecture BDC Practice Questions (Page 2)

Questions 6–10

1. 6foundation · easy

   What is the primary purpose of the Bitcoin blockchain as a distributed ledger?

   • ATo enable anonymous communication between network participants
   • BTo store executable smart contracts that run automatically on every node
   • CTo provide a decentralized file storage system for arbitrary data
   • DTo maintain a tamper-evident, chronological record of all valid Bitcoin transactions
   Reveal Solution Discussion Select an answer first
2. 7application · medium

   A developer is building a Bitcoin wallet that must let users verify that a received transaction is included in a block without downloading the entire blockchain. The wallet will request a proof from a full node. Which data structure and verification method should the developer use?

   • ARequest the block hash and compare it with the transaction's txid to confirm the transaction is in that block.
   • BRequest the transaction's UTXO set and check that the output exists in the current UTXO database.
   • CRequest the full block and verify every transaction in it by re-running the scriptSig and scriptPubKey of each transaction.
   • DRequest the block header and the Merkle branch (path) for the transaction, then recompute the Merkle root and compare it with the root in the header.
   Reveal Solution Discussion Select an answer first
4. 8foundation · easy

   In Bitcoin, what does a UTXO represent?

   • AA cryptographic key pair used to sign transactions
   • BAn output of a transaction that can be used as input to a new transaction
   • CA fee paid to miners for including a transaction in a block
   • DA record of all transactions ever made by a user
   Reveal Solution Discussion Select an answer first
5. 9foundation · easy

   What is Bitcoin Script?

   • AA Turing-complete language that allows arbitrary computation
   • BA high-level programming language similar to Python
   • CA stack-based scripting language used to define the conditions for spending bitcoins
   • DA scripting language used to create smart contracts on Ethereum
   Reveal Solution Discussion Select an answer first
6. 10foundation · easy

   What is the purpose of the nonce field in a Bitcoin block header?

   • ATo identify the previous block in the chain
   • BTo allow miners to vary the block header to find a valid Proof of Work
   • CTo store the digital signature of the miner
   • DTo record the exact time the block was created
   Reveal Solution Discussion Select an answer first