Blockchain Quiz

1. What is a blockchain, and how does it differ from traditional databases?

• Blockchain is centralized with a single point of control.

• Blockchain is a decentralized, distributed ledger that records transactions securely and transparently.

• Blockchain only works for cryptocurrency transactions.

• Blockchain replaces physical databases with cloud databases.

2. Name three key features of blockchain technology.

• Decentralization, immutability, transparency

• Scalability, encryption, centralization

• Privacy, control, isolation

• Efficiency, flexibility, secrecy

3. What is meant by "decentralization" in the context of blockchain?

• Only one node controls the network.

• No single entity controls the network; all participants have equal control.

• All transactions are private and invisible.

• Blockchain only works in local networks.

4. Explain the term "distributed ledger" in blockchain technology.

• A database stored on a single server.

• A ledger shared and synchronized across multiple nodes in the network.

• A ledger that only stores financial transactions.

• A ledger stored in cloud servers.

5. Why is blockchain considered tamper-proof?

• Data is encrypted using private keys.

• Transactions are centralized.

• Cryptographic hashing and block linking make tampering computationally infeasible.

• Nodes approve changes through a manual voting process.

6. What is a "block," and what key information does it contain?

• Only the data of the transaction

• Transaction data, a timestamp, a unique hash, and the hash of the previous block

• A list of network users

• A list of network users

7. How are blocks linked together in a blockchain?

• Using timestamps

• Using public keys

• Using the hash of the previous block

• Using sequential numbers

8.What is the role of cryptographic hashing in blockchain?

• Securing the data and ensuring its integrity by generating a unique hash for each block.

• Encrypting private messages.

• Storing user passwords.

• Speeding up the transaction process.

9. What consensus mechanism does Bitcoin use?

• Proof of Stake (PoS)

• Proof of Authority (PoA)

• Proof of Work (PoW)

• Proof of Ownership

10. What are the differences between Proof of Work (PoW) and Proof of Stake (PoS)?

• PoW is based on energy consumption, PoS selects validators based on coin holdings.

• PoW is cheaper, PoS is more energy-intensive.

• PoW selects validators randomly, PoS uses complex calculations.

• PoW is centralized, PoS is decentralized.