Question 1

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 2

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 3

When considering smart contracts and the blockchain it's good

Options :

A : to 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 : to 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 : to 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 4

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 5

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