A developer is building a DApp that lets users create and manage digital wills. The DApp must ensure that the will is executed exactly as written and cannot be altered after creation. Which Ethereum feature is most essential for this requirement?

The Ethereum Name Service (ENS)

The proof-of-stake consensus mechanism

Smart contracts that are immutable once deployed

A developer is troubleshooting why their DApp cannot connect to the Ethereum network. They are using a local node and a Web3.js library. The node is running, but the DApp reports 'connection refused'. What is the most likely cause?

The Web3.js library is configured to connect to the wrong port or host.

The wallet does not have enough Ether.

The node is not synchronized with the network.

What is the primary purpose of the Ethereum platform?

To provide a decentralized platform for deploying and executing smart contracts and building decentralized applications (DApps).

To create a private, permissioned blockchain exclusively for use by financial institutions.

To provide a high-throughput payment network that processes millions of transactions per second with near-zero fees.

To serve as a centralized database for storing large-scale off-chain data for enterprise applications.

A project manager is reviewing the history of Ethereum to understand why the network transitioned from proof-of-work to proof-of-stake. Which of the following was a primary motivation for this transition?

To increase the block size limit

EC-CouncilBlockchain Developer Certification

Domain 5Objective 1

Ethereum's Purpose, Ecosystem, and Evolution BDC Practice Questions (Page 2)

Part of the Ethereum and Smart Contract Development domain, which makes up ~11% of our current practice bank.

42questions here

9free pages

3concepts

Questions 6–10

6application · medium
A developer is building a DApp that lets users create and manage digital wills. The DApp must ensure that the will is executed exactly as written and cannot be altered after creation. Which Ethereum feature is most essential for this requirement?
Select an answer first
7expert · hard
A developer is troubleshooting why their DApp cannot connect to the Ethereum network. They are using a local node and a Web3.js library. The node is running, but the DApp reports 'connection refused'. What is the most likely cause?
Select an answer first
8foundation · easy
What is the primary purpose of the Ethereum platform?
Select an answer first
9application · medium
A project manager is reviewing the history of Ethereum to understand why the network transitioned from proof-of-work to proof-of-stake. Which of the following was a primary motivation for this transition?
Select an answer first
10application · medium
A developer is choosing a client to run an Ethereum node that will be used to validate transactions and serve data to DApps. They want a client that is widely used and actively maintained. Which of the following is a popular execution client?
Select an answer first

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