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

When defining a new datatype:

Options :

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

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

C : it-s not possible to generate new datatypes in Solidity

Answer: B

Question 4

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

Question 5

The JSON-RPC Protocol:

Options :

A : is used to communicate between blockchain nodes

B : is used to ensure safe communication between miners

C : is a mean of dumping the blockchain data in a so-called consensus export

D : is used to communicate between the blockchain node and externally running applications

Answer: D

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