Bitcoin Network and Its Transactions BDC Practice Questions (Page 5)

Questions 21–25

1. 21expert · hard

   A developer is designing a Bitcoin wallet that must support SegWit (bech32) addresses. The wallet creates a transaction that spends a SegWit UTXO. What is the key difference in the transaction structure compared to a legacy P2PKH transaction?

   • AThe transaction uses a different hashing algorithm for the signature.
   • BThe public key is included in the scriptSig instead of the witness.
   • CThe transaction must include a separate output for the change.
   • DThe signature is moved to a separate witness field, reducing the transaction size and fees.
   Reveal Solution Discussion Select an answer first
2. 22application · medium

   A user signs a Bitcoin transaction with their private key and broadcasts it to a full node. The transaction has a fee that is below the current minimum relay fee. What is the most likely outcome?

   • AThe node will accept the transaction and forward it, but miners will ignore it.
   • BThe node will accept the transaction but delay forwarding it until the fee market clears.
   • CThe node will accept the transaction and include it in the next block it mines.
   • DThe node will reject the transaction and not forward it to other nodes.
   Reveal Solution Discussion Select an answer first
4. 23application · medium

   A user wants to send a Bitcoin transaction with a fee that is high enough to be included in the next block but not overpay. The mempool currently has many transactions with varying fee rates. What should the user's wallet do?

   • ASet the fee rate based on the current network congestion and the desired confirmation time.
   • BSet the fee to zero and rely on the transaction being included eventually.
   • CSet the fee to the minimum relay fee, which is always sufficient for the next block.
   • DSet the fee to the highest fee rate in the mempool to guarantee inclusion.
   Reveal Solution Discussion Select an answer first
5. 24application · medium

   A user wants to estimate the fee for a Bitcoin transaction. The transaction has 2 inputs and 2 outputs, and the estimated size is 300 bytes. The current recommended fee rate is 15 sat/vB. What is the estimated fee in satoshis?

   • A6000 satoshis
   • B3000 satoshis
   • C1500 satoshis
   • D4500 satoshis
   Reveal Solution Discussion Select an answer first
6. 25foundation · easy

   During transaction validation, what does a node do with the combined script (scriptSig + scriptPubKey)?

   • AIt stores the script in the blockchain without further processing
   • BIt decrypts the script using the recipient's private key
   • CIt compares the script to a list of approved scripts
   • DIt executes the script to verify that the unlocking conditions are met
   Reveal Solution Discussion Select an answer first