Blockchain Architecture and Its Core Components BBLC Practice Questions (Page 6)

Questions 26–30

1. 26foundation · easy

   Which part of a block contains the cryptographic hash of the previous block?

   • ATransaction data
   • BMerkle root
   • CBlock header
   • DBlock body
   Reveal Solution Discussion Select an answer first
2. 27foundation · easy

   What happens to a transaction after it is broadcast to the network?

   • AIt is sent to a central authority for approval
   • BIt is immediately added to the blockchain
   • CIt is encrypted and stored on a public cloud
   • DIt is validated by nodes and placed in a pool of pending transactions
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4. 28application · medium

   A developer is explaining to a client why changing a single character in a transaction would be detected by the network. Which property of cryptographic hashing is the primary reason?

   • AThe hash function is reversible, allowing the original data to be recovered.
   • BA small change in the input produces a completely different hash output.
   • CThe hash function produces a fixed-size output regardless of input length.
   • DThe hash function is deterministic, so the same input always produces the same output.
   Reveal Solution Discussion Select an answer first
5. 29application · medium

   A developer is designing a system to store document hashes on a blockchain for notarization. They want to prove that a document existed at a certain time without revealing its contents. Which approach uses blockchain architecture correctly?

   • AStore the full document content in a transaction on the blockchain.
   • BCompute the hash of the document and store the hash in a transaction on the blockchain.
   • CEncrypt the document and store the encrypted file in the block.
   • DStore the document's metadata (e.g., file name and size) in a transaction.
   Reveal Solution Discussion Select an answer first
6. 30foundation · easy

   What is a key characteristic of a distributed ledger technology (DLT)?

   • AData is stored only on a central server and accessed via the internet
   • BA single entity controls all data and validates all transactions
   • CTransactions are processed only by a designated authority
   • DThe ledger is replicated and synchronized across multiple nodes
   Reveal Solution Discussion Select an answer first