Selected MCQ

Current Question
Which cryptocurrency uses a blockchain but was the first to implement smart contracts?
  • A. Bitcoin
  • B. Ethereum
  • C. Litecoin
  • D. Ripple
Correct Answer: B
Explanation:
Ethereum introduced smart contracts on the blockchain.
Related Question 1
What does a 'smart contract' on a blockchain enable?
  • A. Self-executing code enforcing an agreement
  • B. Creating private keys
  • C. Consensus mining
  • D. Physical shipping
Correct Answer: A
Explanation:
Smart contracts are code on a blockchain that execute actions when conditions are met.
Related Question 2
Which data structure uses the LIFO (Last In First Out) access method?
  • A. Queue
  • B. Stack
  • C. Graph
  • D. Hash table
Correct Answer: B
Explanation:
A stack uses Last-In-First-Out order for insertion and removal.
Related Question 3
In a blockchain, what is the role of a "smart contract"?
  • A. A protocol for mining
  • B. A self-executing program that enforces rules
  • C. A central authority validating blocks
  • D. A mechanism to anonymize transactions
Correct Answer: B
Explanation:
Smart contracts are programs stored on the blockchain that execute automatically when conditions are met.
Related Question 4
What ensures blockchain data integrity across nodes?
  • A. Public database
  • B. Hash-linked blocks and consensus
  • C. Encryption keys only
  • D. Trusted server
Correct Answer: B
Explanation:
Blockchain uses cryptographic hashes linking blocks and consensus protocols to maintain integrity.
Related Question 5
What is a token in blockchain contexts?
  • A. A physical key
  • B. A digital asset representing value or rights
  • C. A password
  • D. VPN software
Correct Answer: B
Explanation:
In blockchain, a token is a digital unit of value or access rights recorded on the ledger.