Free Blockchain CBDE Exam Questions

Become Blockchain Certified with updated CBDE exam questions and correct answers

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Total 102 Questions | Updated On: Apr 27, 2026

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Question 1

Public Keys vs. Private Keys. Which statement is true?

A : Public Key is for Signing Transactions, the Private Key must be given out to verify the signature.

B : Private Key signs transactions, the Public Key can verify the signature

C : Private Key is to generate a Public Key. The Public Key can sign transactions, the address is here to verify the transactions

Answer: B

Question 2

When using assert to check invariants and it evaluates to false:

A : l gas is consumed.

B : l remaining gas is returned

Answer: A

Question 3

Unit-Testing on a local chain is important, because it helps you:

A : run tests quickly and especially for free, compared to continuous deployment on the MainNetwork. This way you save a lot of fees, time and costs

B : run tests in an environment where logging is activated. On the Main-Net you have no access to transaction logs and this is ultimately the information you need to debug your contracts

C : avoid regression bugs with contracts that are updated constantly on the main-net. Once you update a contract on the main-net, the address stays the same, but the code changes and this can have disastrous side-effects.

Answer: A

Question 4

It’s possible to access the blockchain via an Ethereum Node:

A : ly via JavaScript because there is the proprietary Web3.js library.

B : by any programming language, as long as it adheres to the JSON-RPC standard.

Answer: B

Question 5

Smart Contracts can be written in:

A : va, C++, Solidity and JavaScript, because the Ethereum Blockchain is completely language agnostic and cross compilers exist for every major language

B : lidity, Viper, LLL and Serpent, because those are high level languages that are compiled down to bytecode.

C : lidity and JavaScript, because those are the official first implementations for Distributed applications and the Blockchain supports those languages fully.

Answer: B

Page: 1 / 21

Total 102 Questions | Updated On: Apr 27, 2026

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