Blockchain Technology and Cryptocurrencies

1. : What is blockchain primarily used for?
(A) Designing websites
(B) Recording and verifying transactions in a secure and decentralized way
(C) Sending emails
(D) Editing images

2. : Which of the following is the first cryptocurrency based on blockchain?
(A) Ethereum
(B) Ripple
(C) Bitcoin
(D) Litecoin

3. : In blockchain, each block contains:
(A) Only images
(B) Data, hash of the block, and hash of the previous block
(C) A password only
(D) Random numbers only

4. : What does decentralization in blockchain mean?
(A) Data stored in a single central server
(B) Data distributed across a network of nodes
(C) Data erased after every transaction
(D) Only banks can access data

5. : What is the process of validating blockchain transactions called?
(A) Mining
(B) Hosting
(C) Hashing
(D) Clustering

6. : Ethereum is mainly known for supporting:
(A) Only digital currency
(B) Smart contracts and decentralized applications (DApps)
(C) File storage
(D) Email services

7. : Which type of blockchain is open to everyone and permissionless?
(A) Private Blockchain
(B) Public Blockchain
(C) Hybrid Blockchain
(D) Consortium Blockchain

8. : Which cryptographic technique ensures security in blockchain?
(A) Hashing
(B) Watermarking
(C) Compression
(D) Encoding

9. : One major advantage of cryptocurrencies is:
(A) Completely centralized control
(B) Fast, borderless, and secure transactions
(C) Guaranteed constant value
(D) Requires no internet

10. : What is a major challenge of cryptocurrencies?
(A) High transparency
(B) Price volatility and regulatory concerns
(C) Decentralized record keeping
(D) Peer-to-peer transactions