FREE Certified Blockchain Professional (CBCP) Smart Contracts and DApps Questions and Answers

Question 1

A smart contract is designed to release payments to a supplier only after a shipment's arrival is confirmed by an IoT sensor.
The blockchain network itself cannot directly access data from the IoT sensor.
Which of the following is required to securely and reliably feed the external data to the smart contract?

Accepted Answer

A blockchain oracle

Answer

A centralized server owned by the shipping company

Answer

A direct API call from the smart contract to the IoT device

Answer

Manual data entry by a network administrator

Question 2

Which of the following best describes the core architectural difference between a traditional application and a Decentralized Application (DApp)?

Accepted Answer

The backend logic of a DApp is executed on a peer-to-peer network via smart contracts, whereas a traditional app's backend runs on centralized servers.

Answer

DApps use HTML and CSS for the frontend, while traditional applications use proprietary languages.

Answer

DApps store data on a centralized database for faster retrieval, unlike traditional apps which use distributed storage.

Answer

Traditional applications are always open-source, while DApps are typically closed-source to protect the smart contract logic.

Question 3

A developer is creating a smart contract on Ethereum and is concerned about the high computational costs associated with a complex function. Which of the following is a primary reason to optimize the smart contract code for 'gas' consumption?

Accepted Answer

To reduce the monetary transaction fees users must pay to execute the contract's functions.

Answer

To increase the physical storage size of the smart contract on the blockchain.

Answer

To improve the readability of the code for other developers.

Answer

To make the smart contract's execution non-deterministic.

Question 4

A development team is launching a new cryptocurrency on the Ethereum blockchain that will be used for payments within their DApp. They need to ensure their token is compatible with various wallets and exchanges. Which token standard should they implement for this fungible token?

Accepted Answer

ERC-20

Answer

ERC-721

Answer

ERC-1155

Answer

ERC-998

Question 5

A Decentralized Autonomous Organization (DAO) is being established to manage a DeFi protocol. How are major decisions, such as updating smart contract parameters or allocating treasury funds, typically made in a DAO?

Accepted Answer

Through proposals and voting by community members who hold governance tokens.

Answer

By the lead development team without external input.

Answer

By a centralized board of directors appointed by the founders.

Answer

Through a hierarchical management structure led by a CEO.

Question 6

A key characteristic of a smart contract is that once it is deployed on the blockchain, its code cannot be altered. What is this property called?

Accepted Answer

Immutability

Answer

Determinism

Answer

Autonomy

Answer

Customizability