Objective Question Blockchain and Smart Contract

What does a typical block in a blockchain primarily consist of?

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  Transactions, Timestamp, and User Information

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  Usernames, Transaction Amounts, and Digital Signatures

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  Transactions, Block Hash, and Previous Block Hash

• Digital Signatures, Encryption Keys, and User Information

How are individual blocks in a blockchain linked together?

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  By including the hash of the previous block in each subsequent block

• Through a sequential numbering system

• Using a central directory

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  By time-stamping each block in chronological order

What ensures the immutability of a blockchain?

• The complexity of the algorithms used

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  The use of digital signatures

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  The inability to alter the hash of a block once it’s part of the chain

• The decentralized nature of the network

What role does consensus play in maintaining the blockchain chain?

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  It is only for resolving conflicts in smart contracts

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  It is used to increase the speed of transaction verification

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  It helps in choosing the blockchain’s next administrative head

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  It ensures all nodes agree on the validity and order of transactions

What is the purpose of a nonce in a blockchain?

• To provide additional security to the block

• To ensure the uniqueness of the block's hash

• To link the block to the previous block

• To verify the authenticity of the transactions

How does a blockchain achieve consensus among multiple nodes?

• By using a centralized authority to validate transactions

• Through a majority vote by all participating nodes

• By solving complex mathematical puzzles through a process called mining

• By randomly selecting a node to make decisions for the entire network

What role does a Merkle tree play in a blockchain?

• To store the entire transaction history of the blockchain

• To efficiently summarize all the transactions in a block

• To encrypt the data stored in each block

• To establish a secure connection between different nodes in the network

What is the key feature of Satoshi Nakamoto's invention in the context of Bitcoin

• A centralized system for managing digital currency transactions

• An emergent consensus mechanism achieved through the asynchronous interaction of independent nodes

• A fixed schedule for reaching consensus in cryptocurrency transactions

• A security model that primarily depends on a central authority or trust

What is the function of the transaction pool, also known as the mempool, in the Bitcoin network?

• It is a collection of all past transactions that have ever been confirmed on the Bitcoin network.

• It serves as a storage for the private keys of Bitcoin users for security purposes.

• It is a pool of valid but unconfirmed transactions that each node independently verifies and maintains.

• It is the mechanism by which new bitcoins are generated and distributed to miners.

What does the arrival of a new block signify for a mining node in the Bitcoin network?

• It indicates the network is undergoing maintenance.

• It acts as an announcement of the winner of the current mining competition and marks the beginning of the next round.

• It is a signal to stop all mining activities.

• It represents a need to update the software used by mining nodes.