Bitcoin Blockchain Architecture BBLC Practice Questions (Page 2)

Questions 6–10

1. 6application · medium

   A cryptocurrency exchange is monitoring the Bitcoin network after a proposed upgrade. The upgrade is a soft fork that restricts the set of valid transactions. The exchange's nodes are running the old software. What is the most likely outcome for the exchange's nodes?

   • AThe nodes will reject all new blocks and the exchange will lose access to the network.
   • BThe nodes will be forked onto a separate chain and will no longer receive updates.
   • CThe nodes will automatically upgrade themselves to the new software to remain compatible.
   • DThe nodes will continue to operate on the same chain and accept all new blocks, but they may not enforce the new restrictions.
   Reveal Solution Discussion Select an answer first
2. 7application · medium

   A developer is explaining to a client why Bitcoin's blockchain is considered immutable. The client asks: 'If someone changes a transaction in an old block, what happens?' Which response is most accurate?

   • AThe change is recorded as a new transaction in the next block, and the old block remains unchanged.
   • BThe change alters that block's hash, which changes the hash stored in the next block, and so on, breaking the chain; the altered block and all subsequent blocks become invalid.
   • CThe change is detected by the network, which automatically reverts the block to its original state using the genesis block's backup.
   • DThe change is allowed only if the block is more than 100 blocks old, because the network considers it final.
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4. 8expert · hard

   A blockchain startup is considering using Bitcoin's proof-of-work consensus for a private enterprise blockchain. The startup's CTO argues that proof-of-work is too energy-intensive and slow for enterprise use. Which alternative consensus mechanism would provide faster finality and lower energy consumption while still maintaining a decentralized network?

   • AProof-of-authority, where a single designated authority validates all transactions.
   • BProof-of-elapsed-time, which requires specialized hardware and is not widely adopted.
   • CProof-of-burn, where validators burn coins to gain the right to mine, which is also energy-intensive.
   • DProof-of-stake, where validators are chosen based on the number of coins they hold and lock up as collateral.
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5. 9foundation · easy

   Who is credited with creating Bitcoin and publishing its original whitepaper?

   • ASatoshi Nakamoto
   • BHal Finney
   • CNick Szabo
   • DVitalik Buterin
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6. 10foundation · easy

   How does the Bitcoin network adjust the difficulty of proof-of-work?

   • AIt adjusts every 2016 blocks to maintain an average block time of about 10 minutes
   • BIt adjusts after every single block based on the number of transactions
   • CIt is set by the miners through a voting process
   • DIt is fixed and never changes
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