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

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

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

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 5

The Fallback function:

Options :

A : cannot receive Ether, not even by adding the payable modifier

B : can contain as much logic as you want, but it’s better to keep it short and not exceed the gas stipend of 2300 gas

C : can be used to avoid receiving ether

Answer: B