Free Blockchain CBDE Exam Questions

Become Blockchain Certified with updated CBDE exam questions and correct answers

Page: 1 / 21

Total 102 Questions | Updated On: Jun 15, 2026

Add To Cart

Question 1

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 2

When defining a new datatype:

A : best to use a contract with public storage variables, so it can be used like a class

B : 's best to use a struct, which is cheaper than deploying a new contract

C : 's not possible to generate new datatypes in Solidity

Answer: B

Question 3

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

Question 4

The Fallback function:

A : nnot receive Ether, not even by adding the payable modifier

B : n contain as much logic as you want, but it’s better to keep it short and not exceed the gas stipend of 2300 gas

C : n be used to avoid receiving ether

Answer: B

Question 5

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

Page: 1 / 21

Total 102 Questions | Updated On: Jun 15, 2026

Add To Cart