Cryptocurrency Fundamentals and Wallets BFC Practice Questions (Page 10)

Questions 46–49

1. 46foundation · easy

   What is the primary purpose of a consensus mechanism in a cryptocurrency network?

   • ATo provide a central authority that can reverse fraudulent transactions.
   • BTo create new cryptocurrency coins at a fixed rate regardless of network activity.
   • CTo encrypt all transactions so that only miners can read them.
   • DTo ensure that all nodes agree on the valid state of the ledger and prevent double-spending.
   Reveal Solution Discussion Select an answer first
2. 47application · medium

   A user sends 0.5 BTC from their wallet to a merchant. The transaction appears in the mempool but remains unconfirmed for several hours. The user checks the fee they attached and sees it is much lower than the current network average. What is the most likely outcome if the user does nothing?

   • AThe transaction will eventually be confirmed once the network difficulty adjusts to accommodate lower fees.
   • BThe transaction will remain in the mempool until a miner includes it, which may take a long time or be dropped after a timeout.
   • CThe transaction will be permanently rejected by the network and the funds will return to the sender's wallet immediately.
   • DThe transaction will be automatically replaced with a higher-fee version by the wallet after a few hours.
   Reveal Solution Discussion Select an answer first
4. 48application · medium

   A user signs a transaction with their private key and broadcasts it. Later, they claim they did not authorize the transaction. What cryptographic property prevents the user from successfully denying the transaction?

   • AIntegrity, because the transaction hash is included in the block.
   • BConfidentiality, because the transaction data is encrypted.
   • CNon-repudiation, because the digital signature can only be produced by the holder of the private key.
   • DAvailability, because the transaction is broadcast to all nodes.
   Reveal Solution Discussion Select an answer first
5. 49foundation · easy

   What is the primary difference between a coin and a token in the cryptocurrency ecosystem?

   • AA coin is mined, while a token is always pre-mined.
   • BA coin is used only for payments, while a token is used only for voting.
   • CA coin is always fungible, while a token is always non-fungible.
   • DA coin operates on its own independent blockchain, while a token is built on top of an existing blockchain.
   Reveal Solution Discussion Select an answer first