Question 1

Ethereum Nodes:
A) must implement the Ethereum protocol and external access can only be done via the proprietary Ethereum Libraries like Web3.js.
B) must implement the Ethereum Protocol and a JSON-RPC to talk with clients.
C) must implement Web3.js to interact with Websites.

Accepted Answer

Ethereum nodes must implement the Ethereum Protocol and provide a JSON-RPC interface to allow clients to interact with the blockchain. This is a standard way for external applications to communicate with Ethereum nodes.

Question 2

A Private Network is:
A) a side Channel to the Ethereum Main Net which costs less gas to run smart contracts.
B) an exact clone of the Rinkeby Test-Network which can be started as virtual machine in the Azure Cloud.
C) a Network running only in a private area, where people cannot join freely and openly.

Accepted Answer

A Private Network is a blockchain network that operates in a restricted environment, where access is controlled and not open to the public.

Question 3

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

Accepted Answer

Ethereum nodes can be accessed using any programming language that supports the JSON-RPC standard, which is a protocol used for communication with Ethereum nodes.

Question 4

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.

Accepted Answer

Consensus in a blockchain network is achieved when every node independently verifies and executes the same transaction, ensuring agreement on the state of the blockchain.

Question 5

Proof of Work (PoW) vs. Proof of Stake.
A) PoW is computationally intensive which requires lots of energy. On the other hand, miners earn straightforward a reward for mining a block and incorporating transactions.
B) PoW is better than PoS, because with PoS we increase the amount of energy spent on the network.
C) PoS is mining with specialized new hardware that has to be purchased with a stack of Ether in the network. Hence the Name: Proof of Stake, which derives from Stack.

Accepted Answer

Proof of Work (PoW) is indeed computationally intensive and requires significant energy consumption. Miners in PoW systems earn rewards for successfully mining blocks.

Question 6

Block Difficulty:
A) is determined by the Ethereum Committee every fortnight to reflect the average amount of transaction and it cannot be influenced by the network itself.
B) increases when the time between mined blocks is below 10 seconds, while it decreases when the time is above 20 seconds.
C) increases when the time between mined blocks is below 20 seconds, while it decreases when the time is above 60 seconds.

Accepted Answer

Block difficulty is adjusted automatically by the network to maintain an average block time of 13 seconds. When the time between mined blocks is below 10 seconds, the difficulty increases to slow down block production. When the time is above 20 seconds, the difficulty decreases to speed up block production.

Question 7

Hashing Mining uses:
A) Keccack256 while internally to hash values it's easy to use the Dagger-Hashimoto to create a meaningful hash.
B) the Dagger-Hashimoto hashing while internally the EVM uses SHA256 which is an alias for Keccack256.
C) the Dagger-Hashimoto hashing while internally the EVM uses Keccack256 which is almost similar to SHA256, but has a different padding so produces different hashes.

Accepted Answer

The Ethereum Virtual Machine (EVM) uses Keccak256 for hashing internally, which is similar to SHA256 but with different padding, resulting in different hashes. Dagger-Hashimoto is used in Ethereum mining.

Question 8

What are Ethereum Nodes?
A) Programs implementing the Ethereum Protocol to talk to each other and JSON-RPC interfaces to talk to the outside world.
B) A Java-Script library to compile and run Solidity Code.
C) A Framework for deploying and running smart contract in a decentralized way.

Accepted Answer

Ethereum nodes are programs that implement the Ethereum protocol, allowing them to communicate with each other and provide interfaces like JSON-RPC for external interaction.

Question 9

A Blockchain Node:
A) can never become a mining node.
B) can always become a mining node.
C) can become a mining node, depending if the implementation has the functionality implemented.

Accepted Answer

A blockchain node can become a mining node if the implementation supports mining functionality. Not all nodes are set up to mine, but they can be configured to do so if the necessary software and hardware requirements are met.

Question 10

Which is the right order for Denominations?
A) Wei, Finney, Szabo, Ether, Tether.
B) Finney, Szabo, Mether, Gwei.
C) Gwei, Szabo, Finney, Ether.

Accepted Answer

The correct order for denominations is Gwei, Szabo, Finney, Ether. Gwei is the smallest denomination, followed by Szabo, Finney, and Ether.

Question 11

To get most out of the blockchain, it is best:
A) to use it for the whole business logic. It's always best to have everything in once place.
B) to use it only for things which need the benefits of the blockchain.

Accepted Answer

Blockchain is best suited for applications that require transparency, security, and immutability.

Question 12

What's the correct scientific notation?
A) 1 Ether = 10^18 wei, 10^9 Gwei, 10^3 Finney
B) 1 Ether = 10^19 wei, 10^13 Gwei, 10^3 Finney
C) 1 Ether = 10^16 wei, 10^13 Gwei, 10^3 Finney
D) 1 Ether = 10^18 wei, 10^6 Gwei, 10^6 Finney

Accepted Answer

1 Ether is equal to 10^18 wei, 10^9 Gwei, and 10^3 Finney.

Question 13

Transactions containing the same data to create the same smart contract are:
A) always having the same signature.
B) having a different signature because of the nonce which changes upon every transaction.

Accepted Answer

The signature of a transaction changes with each transaction due to the inclusion of a nonce, which is a unique number that increments with each transaction to ensure that each transaction is unique, even if the data is the same.

Question 14

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.

Accepted Answer

Engaging the community early through a bug-bounty program can help identify and fix bugs before they become critical issues, enhancing the security and reliability of smart contracts.

Question 15

Which statement is true about the EVM?
A) While the EVM is Sandboxed, it isn't as powerful as the Bitcoin Network, because it's not Turing Complete.
B) The EVM can't access hardware layers or anything outside a blockchain node because it's sandboxed.
C) The EVM is extremely powerful, turing complete and perfect for doing computational intensive things, because of the direct access to the graphics card.

Accepted Answer

The answer of Which statement is true about the EVM?
A)...

Question 16

What are Private Keys used for?
A) To Protect the Public Keys by being cryptographically significant.
B) To Sign Transactions And To Derive an Address From.
C) To Generate An Address which can sign transactions.

Accepted Answer

Private keys are used to sign transactions and to derive an address from.

Question 17

Sending one Ether is actually internally translated:
A) to Wei, so it will send the equivalent of 10^18 Wei.
B) to Finney, so it will send the equivalent of 10^3 Finney.
C) to Szabo, so it will send the equivalent of 10^6 Szabo.

Accepted Answer

One Ether is equivalent to 10^18 Wei, which is the smallest denomination of Ether.

Question 18

When a new block is mined:
A) a list of transactions as well as uncles is incorporated in the block. All gas that is used during those transactions is added to the miners' balance. Also, the block reward is added to the miner. Then the same transactions are run again by every participating node in the network to achieve consensus.
B) a list of transactions is incorporated in that block. Gas used during the execution is attached to the executing contracts while the block reward is automatically spread across the mining pool to ensure a fair spread. Consensus is reached by a special form of hash code.

Accepted Answer

When a new block is mined, it includes a list of transactions and uncles. The gas used during these transactions is added to the miner's balance, along with the block reward. The transactions are then verified by other nodes to achieve consensus.

Question 19

A Hashing Algorithm is deterministic. What does it mean?
A) it always produces the same output given the same input.
B) it uses equally distributed data to produce the output given a long input.
C) it shouldn't be possible to re-generate the input given the output.

Accepted Answer

A hashing algorithm being deterministic means that it will always produce the same output when given the same input, ensuring consistency and reliability in its operation.

Question 20

Externally Owned Accounts (EoA):
A) are changing their address every time a Transaction is sent because of the nonce.
B) are keeping their address, but on the blockchain a nonce is increased every time they send a transaction to avoid replay attacks.

Accepted Answer

The answer of Externally Owned Accounts (EoA):
A) are changing their...

Exam 2: BTA Certified Blockchain Developer - Ethereum

Ethereum Nodes:

A Private Network is:

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

Consensus is reached:

Proof of Work (PoW) vs. Proof of Stake.

Block Difficulty:

Hashing Mining uses:

What are Ethereum Nodes?

A Blockchain Node:

Which is the right order for Denominations?

To get most out of the blockchain, it is best:

What's the correct scientific notation?

Transactions containing the same data to create the same smart contract are:

Having a bug-bounty program early on:

Which statement is true about the EVM?

What are Private Keys used for?

Sending one Ether is actually internally translated:

When a new block is mined:

A Hashing Algorithm is deterministic. What does it mean?

Externally Owned Accounts (EoA) :