Free Blockchain CBDE Exam Questions

Become Blockchain Certified with updated CBDE exam questions and correct answers

Page: 1 / 21

Total 102 Questions | Updated On: Apr 30, 2020

Add To Cart

Question 1

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 2

When considering smart contracts and the blockchain it's good

A : move all existing logic to the blockchain, so everything runs on the same system. This way it might be more complex, but easier to maintain

B : move only those parts to the blockchain that really need the blockchain. This way smart contracts can be easier to read, easier to test and are not so complex

C : move those parts to the blockchain that deal with Ether transfers. All other parts can remain in traditional database systems. This way only the value-transfer is on the blockchain.

Answer: B

Question 3

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 4

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 5

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

Page: 1 / 21

Total 102 Questions | Updated On: Apr 30, 2020

Add To Cart