Blockchain Technology Solved MCQs

Blockchain Technology Solved MCQs 1–10: Basics of Blockchain What is Blockchain? A) A type of database B) A cryptocurrency C) A programming ...

Blockchain Technology Solved MCQs

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1–10: Basics of Blockchain

1. What is Blockchain?
   A) A type of database
   B) A cryptocurrency
   C) A programming language
   D) A web browser
   ✔️ Answer: A
   Explanation: Blockchain is a distributed, immutable ledger or database that stores information in blocks.

2. Who is credited with the invention of blockchain technology?
   A) Vitalik Buterin
   B) Elon Musk
   C) Satoshi Nakamoto
   D) Charles Babbage
   ✔️ Answer: C
   Explanation: Satoshi Nakamoto introduced blockchain as part of Bitcoin in 2008.

3. What is a block in the blockchain?
   A) A physical chain
   B) A type of currency
   C) A digital record containing transactions
   D) A password
   ✔️ Answer: C

4. Which of the following is true about blockchain?
   A) Centralized
   B) Only one copy of data
   C) Decentralized and distributed
   D) Temporary
   ✔️ Answer: C

5. What links one block to the next in a blockchain?
   A) Password
   B) Signature
   C) Hash of the previous block
   D) Timestamp
   ✔️ Answer: C

6. Which cryptographic technique secures blockchain data?
   A) Caesar cipher
   B) Public-private key encryption
   C) Base64
   D) SHA-1
   ✔️ Answer: B

7. The consensus algorithm in Bitcoin is:
   A) PoS
   B) PoW
   C) DPoS
   D) PoA
   ✔️ Answer: B
   Explanation: Bitcoin uses Proof of Work (PoW) to validate transactions.

8. Which programming language is often used for smart contracts in Ethereum?
   A) Python
   B) Java
   C) Solidity
   D) PHP
   ✔️ Answer: C

9. What is mining in blockchain?
   A) Generating new coins
   B) Validating transactions and adding blocks
   C) Sending emails
   D) Blocking users
   ✔️ Answer: B

10. Which is the first blockchain-based cryptocurrency?
    A) Ethereum
    B) Dogecoin
    C) Litecoin
    D) Bitcoin
    ✔️ Answer: D

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11–20: Blockchain Components and Features

11. A blockchain ledger is:
    A) Centralized
    B) Private
    C) Immutable
    D) Editable
    ✔️ Answer: C

12. A decentralized network ensures:
    A) One point of failure
    B) Greater control
    C) No central authority
    D) Less privacy
    ✔️ Answer: C

13. What is a hash function?
    A) A sorting algorithm
    B) A mathematical function used to encrypt data
    C) A server
    D) A virus
    ✔️ Answer: B

14. Which property of blockchain makes it tamper-proof?
    A) Decentralization
    B) Hashing and consensus
    C) Rebooting
    D) Central storage
    ✔️ Answer: B

15. The full copy of blockchain is stored by:
    A) Node
    B) Wallet
    C) User
    D) Admin
    ✔️ Answer: A

16. Which block contains the first transaction in a blockchain?
    A) Genesis block
    B) Root block
    C) Main block
    D) Super block
    ✔️ Answer: A

17. What does a node do in a blockchain?
    A) Only store data
    B) Only mine blocks
    C) Maintain and validate blockchain
    D) Generate images
    ✔️ Answer: C

18. Which of the following is NOT a feature of blockchain?
    A) Transparency
    B) Immutability
    C) Central control
    D) Security
    ✔️ Answer: C

19. Which term refers to breaking up blockchain into smaller parts?
    A) Partitioning
    B) Forking
    C) Sharding
    D) Chunking
    ✔️ Answer: C

20. Which ledger type does blockchain represent?
    A) Private
    B) Public
    C) Distributed
    D) Linear
    ✔️ Answer: C

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21–30: Blockchain Types and Use Cases

21. Public blockchains are:
    A) Permissioned
    B) Private
    C) Open to anyone
    D) Government restricted
    ✔️ Answer: C

22. Which blockchain is primarily used for smart contracts?
    A) Bitcoin
    B) Ethereum
    C) Ripple
    D) Litecoin
    ✔️ Answer: B

23. A private blockchain is typically used by:
    A) Open source developers
    B) Crypto traders
    C) Enterprises and organizations
    D) Miners
    ✔️ Answer: C

24. Which of the following is a use case of blockchain in healthcare?
    A) Video conferencing
    B) Secure patient data
    C) Treating diseases
    D) Medical exams
    ✔️ Answer: B

25. Blockchain in supply chain improves:
    A) Manual entry
    B) Product traceability
    C) Cost of goods
    D) Advertising
    ✔️ Answer: B

26. NFTs are based on which technology?
    A) AI
    B) IoT
    C) Blockchain
    D) 3D Printing
    ✔️ Answer: C

27. Which industry uses blockchain for anti-counterfeiting?
    A) Gaming
    B) Textile
    C) Pharmaceuticals
    D) Tourism
    ✔️ Answer: C

28. What is DeFi?
    A) Data Firewall
    B) Decentralized Finance
    C) Default Internet
    D) Digital File
    ✔️ Answer: B

29. Which cryptocurrency platform is focused on DeFi?
    A) Dogecoin
    B) Ethereum
    C) Bitcoin Cash
    D) Litecoin
    ✔️ Answer: B

30. Which tech giant is involved in enterprise blockchain (Hyperledger)?
    A) Microsoft
    B) IBM
    C) Google
    D) Oracle
    ✔️ Answer: B

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31–40: Security, Consensus & Protocols

31. Which algorithm is energy-intensive?
    A) PoS
    B) PoA
    C) PoW
    D) DPoS
    ✔️ Answer: C

32. Which consensus algorithm is faster and less energy-consuming?
    A) Proof of Work
    B) Proof of Stake
    C) Hashing
    D) Mining
    ✔️ Answer: B

33. A fork in blockchain means:
    A) Connection break
    B) Two competing versions of the chain
    C) Server crash
    D) Speed up
    ✔️ Answer: B

34. Double-spending means:
    A) Paying twice accidentally
    B) Using the same cryptocurrency for two transactions
    C) Price doubling
    D) Mining rewards
    ✔️ Answer: B

35. 51% attack refers to:
    A) DDoS
    B) Virus
    C) Control of majority of the network’s power
    D) Software update
    ✔️ Answer: C

36. Which of these prevents fraud in blockchain?
    A) Central admin
    B) Firewalls
    C) Consensus mechanism
    D) Smart TVs
    ✔️ Answer: C

37. Zero-knowledge proof provides:
    A) Verification without revealing information
    B) Data loss
    C) Node shutdown
    D) Faster mining
    ✔️ Answer: A

38. Byzantine Fault Tolerance refers to:
    A) A hacking method
    B) A power grid system
    C) Tolerance to dishonest nodes
    D) Computer failure
    ✔️ Answer: C

39. Which blockchain platform is known for fast transactions?
    A) Bitcoin
    B) Solana
    C) Litecoin
    D) Monero
    ✔️ Answer: B

40. Smart contracts are:
    A) Written contracts
    B) Contracts stored and executed on blockchain
    C) Lawyer agreements
    D) PDF documents
    ✔️ Answer: B

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41–50: Current Trends and Blockchain in Pakistan

41. Which Pakistani bank launched blockchain for cross-border payments?
    A) Meezan Bank
    B) Habib Bank
    C) Bank Alfalah
    D) Allied Bank
    ✔️ Answer: C

42. Which city hosts Pakistan’s first blockchain institute?
    A) Lahore
    B) Islamabad
    C) Karachi
    D) Peshawar
    ✔️ Answer: C

43. Which country banned cryptocurrency but explores blockchain?
    A) China
    B) USA
    C) India
    D) UK
    ✔️ Answer: A

44. Which sector in Pakistan can benefit from blockchain in land records?
    A) Education
    B) Health
    C) Real estate
    D) Sports
    ✔️ Answer: C

45. Which Pakistani government body showed interest in blockchain?
    A) PTA
    B) NADRA
    C) SECP
    D) FBR
    ✔️ Answer: C

46. Pakistan’s SBP stance on crypto trading (as of 2025):
    A) Legal
    B) Illegal
    C) Fully regulated
    D) Encouraged
    ✔️ Answer: B

47. Which university offers blockchain courses in Pakistan?
    A) NUST
    B) Punjab University
    C) FAST-NU
    D) All of the above
    ✔️ Answer: D

48. Which layer is Ethereum’s scaling solution?
    A) Layer 0
    B) Layer 1
    C) Layer 2
    D) Layer 3
    ✔️ Answer: C

49. Which of the following is a blockchain-based voting system?
    A) DigiVote
    B) E-Vote
    C) FollowMyVote
    D) iVote
    ✔️ Answer: C

50. Future of blockchain is focused on:
    A) Decentralization
    B) Centralized finance
    C) Power banks
    D) Manual accounting
    ✔️ Answer: A

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