Blockchain Technology Architecture and Platforms 3 — Questions and Answers
Question 1: What does the term 'gas' refer to in Ethereum's architecture?
- A type of token on the Ethereum network
- A unit measuring the computational effort required to execute operations (Correct answer)
- The transaction fee paid in USD
- The storage cost for deploying a smart contract
Correct answer: A unit measuring the computational effort required to execute operations
Gas measures the computational work needed to execute a specific operation on the Ethereum Virtual Machine (EVM), preventing infinite loops and spam.
Question 2: In Hyperledger Fabric, what is the role of the 'orderer' node?
- To execute chaincode (smart contracts)
- To establish consensus by ordering transactions into blocks (Correct answer)
- To store user identity certificates
- To validate node permissions on the network
Correct answer: To establish consensus by ordering transactions into blocks
The orderer service in Hyperledger Fabric is responsible for collecting transactions, ordering them, and packaging them into blocks for distribution.
Question 3: What is a 'genesis block'?
- The largest block in a blockchain by transaction count
- The first block in a blockchain from which all subsequent blocks are chained (Correct answer)
- A special block that stores validator credentials
- A block used for network upgrades
Correct answer: The first block in a blockchain from which all subsequent blocks are chained
The genesis block is block #0 (or #1) — the very first block in a blockchain, hardcoded at network launch and the foundation of the entire chain.
Question 4: What is the Ethereum Virtual Machine (EVM)?
- A cloud server that hosts the Ethereum network
- A Turing-complete runtime environment that executes smart contract bytecode (Correct answer)
- A hardware device for storing ETH securely
- A virtual machine for running Ethereum node software
Correct answer: A Turing-complete runtime environment that executes smart contract bytecode
The EVM is a sandboxed, stack-based virtual machine embedded in every Ethereum node that executes smart contract code deterministically.
Question 5: Which of the following best describes a 'light client' in blockchain networks?
- A node that only processes lightweight tokens
- A node that downloads only block headers rather than full block data (Correct answer)
- A mobile wallet with minimal features
- A client that validates only its own transactions
Correct answer: A node that downloads only block headers rather than full block data
A light client downloads block headers and uses Merkle proofs to verify specific transactions without storing the entire blockchain, reducing hardware requirements.
Question 6: What is the Polkadot relay chain?
- A cross-chain bridge for ERC-20 tokens
- The central chain that provides shared security and interoperability for connected parachains (Correct answer)
- A sidechain for Polkadot's staking operations
- A consensus mechanism for private blockchains
Correct answer: The central chain that provides shared security and interoperability for connected parachains
Polkadot's relay chain is the core blockchain that coordinates consensus, finality, and communication between all the independent parachains in the ecosystem.
Question 7: What does 'on-chain governance' mean in a blockchain protocol?
- A government agency that regulates blockchain activity
- A system where protocol changes are proposed and voted on directly via blockchain transactions (Correct answer)
- Governance rules hardcoded at genesis and immutable
- Smart contract auditing by node operators
Correct answer: A system where protocol changes are proposed and voted on directly via blockchain transactions
On-chain governance allows token holders to submit and vote on protocol upgrade proposals directly on the blockchain, with results automatically enforced by the code.
Blockchain Technology Architecture and Platforms 3
What does the term 'gas' refer to in Ethereum's architecture?