Free Blockchain CBDE Practice Exam with Questions & Answers | Set: 3

to contribute to the box community which is the distributed file system for truffle.

to start with a pre-configured environment for most web-development needs.

to use tools that makes boxing of Dapps for different platforms very easy.

it’s good to use a push over a pull method.

it’s good to use a push and a pull method to ensure that participants can get their money no matter the contract state. In addition to and pushing it should contain a withdraw method.

it's good to use only pull and no push method.

is great, because they often find bugs which weren't considered before.

is not good, because you might give out secrets.

is a must for every developer, because Web3.js changes so often.

is a convenient way because Web3.js is currently still in beta and truffle-contract can handle transactions with JavaScript-promises.

they are both completely different things. Truffle-Contract is a framework while Web3.js is a library.

can only be accessed during calls.

can be accessed during transactions and calls.

it's good to inform users about the updates via a newsletter.

it's good to have the ability to pause a contract in order to manage the money at risk.

Ethereum doesn't upgrade the platform. It's fixed and final.

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.

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.

are stored on chain and are a great way to get a return value when a contract calls another contract.

are stored in something like a side-chain and cannot be accessed by contracts.

are used primarily for debugging exceptions in solidity.

would be better, because it can reduce the amount of energy needed for mining.

would be worse, because it would increase the amount of energy needed for mining.

by the miner nodes which make sure that a transaction is valid.

by every single node in the blockchain network executing the same transaction.

by a cryptographic secure signature algorithm called ECDSA which makes sure that cheating is impossible.