Blockchain & Web3 MCQ

What is a blockchain, at its core?

What links each block to the previous block in a blockchain?

What does "decentralization" mean in the context of blockchain?

What is a "cryptographic hash function" used for in blockchain?

What is the purpose of "mining" in a Proof of Work blockchain like Bitcoin?

What is a "wallet" in the context of cryptocurrency?

What is the difference between a public key and a private key in blockchain wallets?

What is a "smart contract"?

What is Ethereum primarily known for, beyond being a cryptocurrency?

What does "decentralized application" (dApp) mean?

What is a "token" in the Web3/blockchain context?

What does NFT stand for?

What does "fungible" mean when describing a token or asset?

What is a "block explorer"?

What is "gas" in the context of Ethereum?

What is the difference between a "mainnet" and a "testnet"?

What is a "seed phrase" (mnemonic phrase) used for in crypto wallets?

Why is it dangerous to share your wallet's private key or seed phrase?

What is a "consensus mechanism" in a blockchain network?

What is "Proof of Stake" (PoS) as a consensus mechanism?

What is the main difference between Bitcoin and Ethereum in terms of purpose?

What does it mean for blockchain transactions to be "immutable"?

What is a "node" in a blockchain network?

What is a cryptocurrency "exchange"?

What is the difference between a "centralized exchange" (CEX) and a "decentralized exchange" (DEX)?

What is "Web3" generally meant to describe?

What is a "stablecoin"?

What is a "hard fork" in blockchain terminology?

What is the role of a "validator" in a Proof of Stake network?

What does it mean for a smart contract to be "deployed"?

What is "DeFi" short for?

What is a "liquidity pool" in DeFi?

What is "minting" an NFT?

What is a "DAO" (Decentralized Autonomous Organization)?

What is "on-chain" vs "off-chain" data?

What is the purpose of a "block reward"?

What does it mean when a blockchain transaction has been "confirmed"?

What is a "cold wallet"?

What is the purpose of a "transaction fee" on a blockchain network?

What is a "genesis block"?

What problem does the "double-spending" issue solve for in cryptocurrencies, and how does blockchain address it?

What is the Ethereum Virtual Machine (EVM)?

What is the ERC-20 standard used for?

How does the ERC-721 standard differ from ERC-20?

What is a "51% attack"?

What is the purpose of a "Merkle tree" in a blockchain block?

What is a "smart contract audit" and why is it important?

What is a "reentrancy attack" on a smart contract?

What is a "Layer 2" scaling solution in blockchain (e.g., for Ethereum)?

What is the difference between an "optimistic rollup" and a "zk-rollup"?

What is a "cross-chain bridge"?

What is "gas optimization" in smart contract development, and why does it matter?

What is an "oracle" in blockchain, and why is it needed?

What is an "Automated Market Maker" (AMM)?

What is "impermanent loss" in the context of liquidity pools?

What is the purpose of a "multi-signature" (multisig) wallet?

What does "permissionless" mean in the context of public blockchains?

What is the difference between a "permissioned" and "permissionless" blockchain?

What is "slashing" in a Proof of Stake network?

What is the purpose of "The Merge" event for Ethereum?

What is a "sidechain"?

Why might a smart contract use a "proxy pattern" for upgradability?

What is "front-running" in the context of blockchain transactions?

What is the "mempool"?

What is a "governance token"?

What is "yield farming" in DeFi?

What is "tokenomics"?

What is the purpose of a "vesting schedule" for project tokens?

What is "censorship resistance" in the context of public blockchains?

What is the role of "validators" voting on blocks in a Byzantine Fault Tolerant (BFT) consensus protocol?

What is "wrapped" cryptocurrency (e.g., Wrapped Bitcoin, WBTC)?

What is the significance of a smart contract's "state" being stored on-chain?

What does "interoperability" mean for blockchain networks?

What is a "faucet" in the context of testnets?

What is a "flash loan" in DeFi?

What is "staking-as-a-service" offered by some platforms?

What is the purpose of "address whitelisting" in some token contracts or exchanges?

What is a "rug pull" in the context of crypto projects?

What does "composability" mean for DeFi protocols?

Why do some Ethereum transactions specify a "nonce"?

How does a zk-SNARK allow a prover to convince a verifier of a statement's truth without revealing the underlying data?

What is "MEV" (Miner/Maximal Extractable Value) and why is it significant?

What is the core security trade-off illustrated by the "Blockchain Trilemma"?

In an optimistic rollup, what is the purpose of the "challenge period" (dispute window)?

How do "commit-reveal" schemes help mitigate front-running in smart contract interactions?

What does "finality" mean differently in Proof of Work chains like Bitcoin versus chains with explicit finality gadgets (e.g., Ethereum's Casper FFG)?

Why is "data availability" a critical concern for rollups and modular blockchain designs?

What is the purpose of "account abstraction" (e.g., ERC-4337) on Ethereum?

How does a "fraud proof" differ from a "validity proof" in the context of Layer 2 scaling?

What is "state bloat" and why is it a long-term concern for blockchains like Ethereum?

In the context of cryptographic signatures, why do many blockchains use elliptic curve cryptography (e.g., secp256k1) rather than RSA?

What distinguishes a "sharded" blockchain architecture from a single monolithic chain?

Why is "replay protection" important when a blockchain undergoes a hard fork that creates two chains?

How does "stateless" client design aim to address blockchain scalability challenges?

What security property does a "time-lock" (e.g., in a vesting contract or hash time-locked contract, HTLC) provide?

Why might a protocol implement "EIP-1559"-style fee mechanisms (base fee + tip) instead of a simple first-price auction for transaction fees?

What is the significance of "atomicity" in blockchain transactions, especially for complex DeFi operations involving multiple steps?

How can on-chain governance via token-weighted voting lead to "plutocracy" concerns, and what is one proposed mitigation?

Why is "deterministic execution" essential for blockchain consensus across nodes running smart contracts?

What role does a "Verkle tree" aim to play as a potential successor to Merkle Patricia tries in Ethereum?