Free CBDE – BTA Certified Blockchain Developer - Ethereum Practice Test Question

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

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

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

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  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.

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  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.

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  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.
  
  

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  is a framework that helps developers with Testing, Deployment and Management of Smart Contracts and Distributed Applications.

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  is a library that helps developers to connect to Ethereum nodes, because it abstracts the JSONRPC interface.

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  is a framework for Java, similar to Web3.js for JavaScript. It's a great way to develop distributed Java enterprise applications.
  
  

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  to check internal states that should never happen.

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  to check input arguments from users.
  
  

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  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.

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  metadata contains the address, and the size of the smart contract. The ABI Array is generated externally upon deploying the smart contract.

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  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.
  
  

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  all gas is consumed.

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  all remaining gas is returned.
  
  

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  the timestamp is based on the time zone of the miner, that is why it changes the difficulty continuously to reflect network latency.

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  the timestamp can't be influenced by a miner and is generally considered safe to be used for randomness on the blockchain.

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  the timestamp can be influenced by a miner to a certain degree but it's always independent from the time-zone.
  
  

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  to Wei, so it will send the equivalent of 10^18 Wei.

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  to Finney, so it will send the equivalent of 10^3 Finney.

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  to Szabo, so it will send the equivalent of 10^6 Szabo.
  
  

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  While the EVM is Sandboxed, it isn't as powerful as the Bitcoin Network, because it's not Turing Complete.

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  The EVM can't access hardware layers or anything outside a blockchain node because it's sandboxed.

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  The EVM is extremely powerful, turing complete and perfect for doing computational intensive things, because of the direct access to the graphics card.
  
  

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  True, but it's still good to use Ganache, or even a real private network for testing.

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  False, it's necessary to use Ganache or even a real private network for testing.