Free Blockchain CBDE Exam Dumps Questions & Answers

With the truffle config file you can manage:

• A.  different Networks to deploy your contracts to. This way you can easily deploy to a local blockchain, the main-net or the Ropsten/Rinkeby Test-Net with only one parameter.
• B.  the amount of gas your contract deployment and transactions, against your contract, will need. This way you can essentially lower the gas costs over traditional web3.js dApps.
• C.  you can manage your secret API keys to the Ethereum Network. This way you can get access to several different Ethereum nodes at the same time without the need to switch your keyfiles.

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

• A.  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.
• B.  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.
• C.  PoW is better than PoS, because with PoS we increase the amount of energy spent on the network.

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.

When you are programming a game like poker of battleships where you need to hide opponents values is:

• A.  You can't hide anything on the blockchain, because the information is public, just the call is private which means only other smart contracts would be limited in accessing that information.
• B.  with private state variables. This way nobody else other than the smart contract itself can see the information
• C.  with external contracts holding those values. This way we can make sure that the information flow is following a clear logic and nobody else can access this information.

When solidity is compiled then also Metadata is generated:

• A.  the ABI array and the Metadata are not generated when solidity is compiled to bytecode, its generated by a migration software which deploys the smart contract on the blockchain.
• B.  the Metadata contains the ABI Array, which defines the Interface to interact with the Smart Contract. Metadata can also contain the address of the smart contract when it gets deployed.
• C.  metadata contains the address, and the size of the smart contract. The ABI Array is generated externally upon deploying the smart contract.