Blockchain Ecosystem and Use Cases BDC Practice Questions (Page 4)

Questions 16–20

1. 16foundation · easy

   Which layer of the blockchain ecosystem is responsible for providing a user-friendly interface that interacts with smart contracts and blockchain data?

   • AConsensus layer
   • BApplication layer
   • CNetwork layer
   • DData layer
   Reveal Solution Discussion Select an answer first
2. 17expert · hard

   A developer is building a dApp that allows users to trade digital collectibles across different blockchain networks. The dApp needs to support assets on Ethereum and Binance Smart Chain, and users expect to move assets between the chains seamlessly. The developer is concerned about security and user experience. What is the most appropriate solution?

   • AUse a well-audited cross-chain bridge protocol with a decentralized validator set and insurance fund
   • BUse a trusted third-party custodian to hold assets and issue IOUs on each chain
   • CBuild a custom bridge that locks assets on the source chain and mints wrapped tokens on the destination chain
   • DDeploy the dApp on a single blockchain and abandon support for the other
   Reveal Solution Discussion Select an answer first
4. 18application · medium

   A developer is setting up a private Ethereum network for a company's internal record-keeping. They need to ensure that only authorized employees can submit transactions and that the network is not accessible from the public internet. Which configuration is most appropriate?

   • AUse a cloud-based blockchain service without additional configuration.
   • BUse a proof-of-work consensus on a private network.
   • CDeploy a public Ethereum node and use a firewall to restrict access.
   • DDeploy a permissioned network with a consensus mechanism like Clique (PoA) and restrict network access to a private subnet.
   Reveal Solution Discussion Select an answer first
5. 19application · medium

   An art gallery wants to tokenize a painting to prove ownership and enable fractional sales. They want to ensure that the digital token is uniquely linked to the physical artwork. Which approach is most appropriate?

   • ACreate a fungible token that represents a share of the painting.
   • BStore a high-resolution image of the painting on-chain.
   • CCreate a non-fungible token (NFT) that contains a cryptographic hash of the artwork's certificate of authenticity.
   • DUse a centralized database to track ownership and issue a token as a receipt.
   Reveal Solution Discussion Select an answer first
6. 20expert · hard

   A developer is designing a smart contract for a decentralized lending platform. The contract must handle collateralized loans, liquidate positions when collateral value drops, and interact with external price feeds. The developer is concerned about the security of the contract and the reliability of the price data. What is the most critical design consideration?

   • AUsing a single trusted oracle for price feeds to minimize gas costs
   • BHardcoding the collateral ratio in the contract and never allowing it to change
   • CAllowing the contract owner to manually adjust prices in case of oracle failure
   • DImplementing a decentralized oracle network with multiple data sources and aggregation
   Reveal Solution Discussion Select an answer first