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 30, 2020

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Question 1

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 2

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 3

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 4

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 5

To communicate with an Ethereum node via [removed]

A : library you use must make use of the JSON-RPC Interface of an Ethereum Node

B : t Implement the Ethereum Protocol to connect to other Ethereum Nodes.

C : t use Web3.js, which is closed source to communicate to other Ethereum Nodes.

Answer: A

Page: 1 / 21

Total 102 Questions | Updated On: Apr 30, 2020

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