Blockchain CBDE Exam Actual Questions

Topic 1 - Exam A

Question #1 Topic 1

Consensus is reached:

A. by the miner nodes which make sure that a transaction is valid.
B. by every single node in the blockchain network executing the same transaction.
C. by a cryptographic secure signature algorithm called ECDSA which makes sure that cheating is impossible.

Reveal Solution Discussion

Correct Answer: B 🗳️

Question #2 Topic 1

Smart Contracts can be written in:

A. Java, C++, Solidity and JavaScript, because the Ethereum Blockchain is completely language agnostic and cross compilers exist for every major language.
B. Solidity, Viper, LLL and Serpent, because those are high level languages that are compiled down to bytecode.
C. Solidity and JavaScript, because those are the official first implementations for Distributed applications and the Blockchain supports those languages fully.

Reveal Solution Discussion

Correct Answer: B 🗳️

Question #3 Topic 1

Solidity gets compiled:

A. to bytecode that can't be understood by humans.
B. to bytecodes which are essentially opcodes running instruction by instruction.

Reveal Solution Discussion

Correct Answer: B 🗳️

Question #4 Topic 1

Having a bug-bounty program early on:

A. can help to engage the community in testing your smart contracts and therefore help to find bugs early.
B. might be a burden as it is an administrative overhead mainly.
C. is completely useless. Who wants to test beta-ware software? It’s better to start with the bug-bounty program after the contract is released on the main-net.

Reveal Solution Discussion

Correct Answer: A 🗳️