WorksheetsBlockchain Quiz
Total questions: 15
Worksheet time: 15mins
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.
11. Give two examples of how blockchain is used in supply chain management.
Walmart and Ethereum
Walmart and tracking food origins
Walmart and banks
Bitcoin and medical records
12. How does blockchain enhance the security of online voting systems?
By providing full transparency and immutability, reducing fraud.
By encrypting the voters’ identities.
By allowing centralized monitoring.
By storing votes in offline systems.
13. Explain how smart contracts can replace intermediaries in business transactions.
By manually approving each contract.
By executing automatically when conditions are met, eliminating middlemen.
By using centralized authorities for validation.
By encrypting the data of contracts.
14. What role does blockchain play in managing medical records?
Allows patients to manage their own records securely.
Encrypts data for hospitals only.
Stores records in physical databases.
Prevents doctors from accessing patient data.
15. Describe how blockchain can improve cross-border payments.
By reducing transfer fees and enabling faster transactions.
By replacing banks entirely.
By ensuring only high-value transfers are allowed.
By using physical servers for payment processing.
