NEW
Font size
WorksheetsBlockchain: Beginners to Advanced by Chayan Bhattacharjee
Total questions: 55
Worksheet time: 38mins
What is a blockchain?
A decentralized, distributed ledger
A type of computer virus
A type of search engine
A cloud storage provider
Which of the following is a key feature of blockchain?
Central control
High transaction fees
Immutability
Unlimited scalability
What is the Blockchain?
As a database, a blockchain stores information in real life in real format.
This is where you send all your money and NFTs
Acts as a database. A blockchain stores information electronically in digital format.
It's a receipt of all transactions.
When you stack blocks together in real life you create a chain.
What is stored in each block of a blockchain?
Only user IDs
A list of passwords
Transaction data, hash, and previous hash
Program files
Which technology enables blockchain to prevent tampering?
Optical recognition
Hashing
Machine Learning
Virtualization
What is a Centralized Exchange?
This is a peer-to-peer marketplaces where cryptocurrency traders make transactions directly without handing over management of their funds to an intermediary or custodian.
Centralized exchanges are unregulated, don't need licenses to operate, and are non-compliant with the regulatory authorities.
This is where you store your secret pass phrase
Centralized exchanges are regulated, need licenses to operate, and are compliant with the regulatory authorities.
What is a Decentralized Exchange?
Decentralized exchanges are regulated, need licenses to operate, and are compliant with the regulatory authorities.
Decentralized exchanges are unregulated, don't need licenses to operate, and are non-compliant with the regulatory authorities.
Decentralized exchanges are peer-to-peer marketplaces where cryptocurrency traders make transactions directly without handing over management of their funds to an intermediary or custodian.
What is a Cold Wallet?
This is a physical device that keeps your crypto assets (e.g., cryptocurrency, NFTs) completely offline
This is a virtual memory that keeps your crypto assets (e.g., cryptocurrency, NFTs) completely online
This is where you store your secret pass phrase
This refers to a virtual currency wallet that is accessible online, and it facilitates cryptocurrency transactions between the owner and end-users
What is a Hot Wallet?
This is a physical device that keeps your crypto assets (e.g., cryptocurrency, NFTs) completely offline
This is where you store your secret pass phrase
This refers to a virtual currency wallet that is accessible online, and it facilitates cryptocurrency transactions between the owner and end-users
What is a Wallet Address?
This is a physical device that keeps your crypto assets (e.g., cryptocurrency, NFTs) completely offline
This is a unique string of numbers and letters (also called a public key) that people can use to send you cryptocurrency and NFTs
This is where you store your secret pass phrase
Which of the following is a consensus mechanism?
Proof of Code
Proof of Work
Proof of Payment
Proof of Stakeholder
What ensures trust in a blockchain network?
Encrypted PDFs
Strong passwords
Centralized verification
Distributed consensus
Who created Bitcoin?
Ethereum Foundation
IBM
Satoshi Nakamoto
What is the maximum supply limit of Bitcoin?
1 million
21 million
Unlimited
100 million
Bitcoin transactions are verified by
Miners
Banks
Government agencies
Stock exchanges
What is a cryptocurrency?
A file format
A physical currency
A digital currency using cryptography
A type of hardware
Which of the following is NOT a cryptocurrency?
Litecoin
PayPal
Ethereum
Bitcoin
What is Minting?
This is a physical device that keeps your crypto assets (e.g., cryptocurrency, NFTs) completely offline
This is a unique string of numbers and letters (also called a public key) that people can use to send you cryptocurrency and NFTs
This is how how your digital art becomes a part of the blockchain
Who created Ethereum?
Vitalik Buterin
Charles Hoskinson
Elon Musk
Larry Page
What makes Ethereum different from Bitcoin?
No blockchain use
Physical nature
Only for government
Smart contract support
What is ETH?
A smart contract
A token on Solana
The native currency of Ethereum
A blockchain explorer
Ethereum uses which consensus (as of now)?
Proof of Work
Proof of Stake
Delegated Proof
Hybrid Voting
Which language is widely used for Ethereum smart contracts?
Java
Python
Solidity
Bash
Which property is important in smart contracts?
Trustless automation
Manual execution
Human supervision
Central verification
What does DApp stand for?
Daily Application
Digital Application
Decentralized Application
Developed Application
NFT stands for
Not Found Token
Non-Fixed Type
Non-Fungible Token
New Fungible Token
NFTs are typically used to represent
Uniform currency
Identical files
Unique digital assets
Real estate tax
What is an NFT (non-fungible token)?
An NFT is a paper asset that represents real-world objects like art, music, in-game items and videos.
An NFT is a fake asset that represents real-world objects like art, music, in-game items and videos.
An NFT is an imaginary asset that represents real-world objects like art, music, in-game items and videos.
An NFT is a digital asset that represents real-world objects like art, music, in-game items and videos.
Which property of blockchain ensures that data, once written, cannot be changed?
Immutability
Scalability
Transparency
Tokenization
What is the genesis block?
The largest block
The first block in a blockchain
A block created by miners
The last block in the chain
Which part of the block ensures that two identical transactions will produce different hashes?
Public key
Private key
Timestamp
Nonce
What determines the reward for mining a Bitcoin block?
Network voting
Predefined halving schedule
Gas fees
Token auction
What is Gas?
This refers to the fee, or pricing value, required to successfully conduct a transaction or execute a contract on the Ethereum blockchain platform.
This is a unique string of numbers and letters (also called a public key) that people can use to send you cryptocurrency and NFTs
This is how how your digital art becomes a part of the blockchain
This is a computer program or a transaction protocol which is intended to automatically execute, control or document legally relevant events and actions according to the terms of a contract or an agreement.
Which of the following events cuts Bitcoin block rewards in half?
Halving
Soft fork
Genesis update
Ledger upgrade
In which layer are Merkle trees and data models defined?
Semantic Layer
Propagation Layer
Application Layer
Execution Layer
Which layer of Ethereum processes smart contract logic?
Execution layer
Consensus layer
Data link layer
Storage layer
Ethereum smart contracts are compiled into what format before execution?
JavaScript
Bytecode
Assembly
Source code
In which layer is the legitimacy and correctness of a transaction verified?
Propagation Layer
Application Layer
Consensus Layer
Semantic Layer
What is the primary function of the Propagation Layer?
Execute smart contracts
Build DApps
Store transaction history
Disseminate transactions and blocks
Which blockchain layer facilitates peer-to-peer communication?
Semantic Layer
Propagation Layer
Application Layer
Execution Layer
Which layer helps maintain the linkage of blocks using previous block hashes?
Semantic Layer
Propagation Layer
Application Layer
Execution Layer
What does the Application Layer deal with?
Blockchain-based and blockchain-enhancing applications
Reaching consensus
Compiling bytecode
Maintaining Merkle trees
What role does the Consensus Layer play in blockchain architecture?
Hosts APIs and smart contracts
Validates transactions and updates accounts
Ensures a consistent state across nodes
Communicates with the user interface
Which consensus mechanism is used by Bitcoin and Ethereum (pre-Merge)?
Proof of Stake (PoS)
Delegated Proof of Stake (dPoS)
Practical Byzantine Fault Tolerance (PBFT)
Proof of Work (PoW)
What is the role of an Ethereum Virtual Machine (EVM)?
Store keys
Execute smart contracts
Maintain liquidity
Manage validator nodes
In tracking perishable goods, how can blockchain enhance efficiency?
By providing real-time temperature data
By automating payments
By encrypting product recipes
By generating promotional content
Which blockchain application can prevent counterfeit products in the supply chain?
Decentralized exchanges
Non-fungible tokens (NFTs)
Digital identity verification
Smart contracts
How can blockchain reduce cross-border payment times?
By using traditional banking channels
By increasing regulatory compliance steps
By eliminating the need for currency conversion
By enabling peer-to-peer transactions without intermediaries
A coffee company wants to ensure the authenticity of its beans from farm to cup. Which blockchain feature is most beneficial?
Smart contracts
Decentralized finance
Immutable ledger
Tokenization
A university is conducting digital student elections and wants the process to be transparent, private, and tamper-proof. What is the ideal blockchain approach?
1. Collect votes via Google Forms.
2. Store results in Excel.
3. Announce winners through WhatsApp.
4. Avoid third-party auditing.
1. Use Ethereum smart contracts to tally votes.
2. Hash each vote before storing.
3. Assign tokens as voting rights.
4. Enable third-party verification of results.
1. Use a public blockchain and reveal all votes.
2. Store voter identities directly on-chain.
3. Allow anonymous logins via email.
4. Skip audit trails.
1. Use a permissioned blockchain where only registered students can vote.
2. Issue anonymized vote tokens linked to student identities.
3. Use smart contracts to prevent double voting.
4. Publish a hash of the final tally to enable public verification without revealing individual votes.
A seafood exporter wants to ensure that temperature-sensitive products are transported under proper conditions. Choose the best blockchain implementation:
1. Use IoT sensors to record temperature.
2. Connect sensors to blockchain in real time.
3. Smart contracts trigger alerts if limits are breached.
4. Use permissioned access for transport partners.
1. Use public Ethereum blockchain.
2. Store raw temperature data on-chain.
3. Disallow regulators from seeing the data.
4. Use NFTs for product licenses.
1. Avoid sensor data to reduce complexity.
2. Use QR codes scanned at delivery points only.
3. Use PoW blockchain to validate delivery time.
4. Share temperature data via SMS.
1. Use private blockchain for internal auditing only.
2. Delay uploading data to end of the day.
3. Record average temperatures only.
4. Use GPS but skip tamper-proof logs.
An independent music platform wants to automate royalty distribution for artists based on stream count. What is the most suitable blockchain-based approach?
1. Tokenize each song or album using NFTs.
2. Record each streaming event immutably on a public ledger.
3. Automate revenue split among artists, labels, and producers using smart contracts.
4. Provide real-time, auditable royalty dashboards for creators.
1. Upload music files to the blockchain directly.
2. Create one token for entire platform content.
3. Allow manual claim submissions for royalties.
4. Hide revenue details for data privacy.
1. Represent each song as a unique NFT.
2. Use on-chain analytics to track streaming.
3. Smart contracts divide revenue among all contributors in real-time.
4. Enable direct payment via crypto wallets.
1. Track streams manually and upload data weekly.
2. Use Excel sheets linked to blockchain smart contracts.
3. Allocate royalties through manual intervention.
4. Store audio files directly on blockchain.
A motor insurance company wants to automate claim approval using real-time crash data from IoT-enabled cars and cross-verification with police reports. Which of the following sequences best fits a blockchain-powered solution?
1. Build a public blockchain for crash events.
2. Allow customers to upload police reports manually.
3. Smart contract disburses claims after manual review.
4. Use an external oracle for crash validation
1. Use a permissioned blockchain to record real-time IoT crash data.
2. Trigger smart contract when crash metrics exceed threshold.
3. Use verified oracle nodes to confirm police reports.
4. Disburse funds automatically if all validations succeed.
1. Use Ethereum smart contracts to receive crash signals.
2. Validate crash against timestamped blockchain entries.
3. Wait for customer-initiated claim submission.
4. Automatically transfer funds if claim approved.
1. Use insurance agent portals to handle requests.
2. Tokenize each claim with NFTs.
3. Upload reports on IPFS without encryption.
4. Make claim payments only via cryptocurrency.
A research journal wants to ensure originality and timestamped proof of submission for scientific papers to prevent plagiarism. Which blockchain-based system works best?
1. Use email timestamps to track submissions.
2. Compare content manually during review.
3. Rely on CMS to archive papers.
4. Assign DOIs without cryptographic proof.
1. Use blockchain to timestamp each manuscript version.
2. Hash and link drafts to author’s public key.
3. Store immutable peer-review records.
4. Use Merkle trees to compare against prior publications.
1. Allow re-submissions without checks.
2. Store manuscripts as PDFs on IPFS with public links.
3. Publish anonymously.
4. Avoid hashing due to file size limits.
1. Hash entire manuscript and store hash on-chain.
2. Timestamp submission using block height.
3. Let authors verify ownership via digital signatures.
4. Record peer-review comments immutably.
A multinational food retailer wants to track the journey of organic produce (like avocados) from farms in Mexico to stores in Canada. They aim to improve transparency, authenticity, and recall efficiency in case of contamination. The data must be shared with farmers, logistics partners, regulatory bodies, and retail managers. They are deciding which type of blockchain and features to implement. Which of the following steps best describe the ideal blockchain implementation strategy for this scenario?
1. Choose a public blockchain like Ethereum for full transparency.
2. Implement smart contracts to monitor every shipping event.
3. Allow farmers to mine blocks and earn gas fees.
4. Use NFTs to represent each avocado.
1. Choose a permissioned blockchain like Hyperledger Fabric.
2. Create unique IDs for each produce batch stored on the blockchain.
3. Allow only verified stakeholders to add/update data.
4. Implement smart contracts to trigger alerts on delay or quality failure.
1. Use a cryptocurrency exchange to list avocado-backed tokens.
2. Publish all data on a public blog.
3. Use proof-of-stake to validate farm credentials.
4. Use DApps to track weather conditions only.
1. Build a private blockchain with access limited to internal employees.
2. Use QR codes to connect with blockchain for data input.
3. Exclude regulators and third-party vendors.
4. Rely on manual update from logistics.
