CBDE

Block Timestamp:A . the timestamp is based on the time zone of the miner, that is why it changes the difficulty continuously to reflect network latency.B . the timestamp can't be influenced by a miner and is generally considered safe to be used for randomness on the blockchain.C . the...

Gas costs accrue on sending a transaction:A . no matter the content.B . only with a new smart contract deployment.C . only interacting with an already deployed smart contract.View AnswerAnswer: A

You interact with a smart contract and see a gas usage of 50,000 gas with a gas cost of 15Gwei. How much Ether would you have to pay to the miner?A . 750,000,000,000,000 WeiB . 750,000,000,000 WeiC . 750,000,000 WeiD . A flat fee of 1 EtherView AnswerAnswer: A

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.View AnswerAnswer: B

Checking the balance of an address inside a loop of a smart contract constantly:A . doesn't cost any gas.B . cost gas every time we check the balance.View AnswerAnswer: B

For Rapid Development Cycles it's good:A . to deploy to the main-network as quickly as possible.B . to use in-memory blockchain simulations, because mining works instantaneously.C . to use a private network at all times, because this is the closest you get to the real network.View AnswerAnswer: B

Externally Owned Accounts:A . can be destroyed using the selfdestruct keyword. This way all remaining ether will be sent to the receiver address, regardless if they have a fallback function or not.B . are bound to a private key which is necessary to sign transactions outgoing from that account.C ....

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...

Go-Ethereum vs. Ganache:A . both are the same, just implemented in a different language.B . with Go-Ethereum you get a real blockchain node where you can create your own local private network, connect to Test-Networks or the Main-Net, while with Ganache you get an in-memory blockchain simulation.C . with Ganache...

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...