Question 1

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

Options :

A : all gas is consumed.

B : all remaining gas is returned

Answer: A

Question 2

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

Options :

A : only 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 3

Smart Contracts can be written in:

Options :

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.

Answer: B

Question 4

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

Options :

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

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

C : The 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 5

To communicate with an Ethereum node via [removed]

Options :

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

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

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

Answer: A

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