A proof-of-stake blockchain allows token holders to delegate their stake to validators. A user delegates to a validator that offers a very high yield but has a history of downtime. What is the primary risk for the user?

The user may receive fewer rewards due to validator penalties

The user's tokens will be slashed if the validator is malicious

The user will lose the ability to vote in governance

The user's tokens will be locked for a longer period

A lending protocol relies on a single price oracle to determine collateral values and trigger liquidations. An attacker manipulates the underlying spot market, causing the oracle to report a falsely low price for a collateral asset, and then liquidates healthy positions at a discount. Which mitigation would be most effective in preventing this type of manipulation?

Use a decentralized oracle network that aggregates prices from multiple independent sources and applies a median or weighted average.

Increase the liquidation threshold so that positions are liquidated earlier, before the oracle price drops too far.

Allow users to submit price updates to the oracle to correct any discrepancies.

Disable liquidations during periods of high volatility.

A user wants to participate in a proof-of-stake network but does not have enough tokens to run a validator. They decide to delegate their tokens to a validator. What is a key consideration when choosing a validator?

The validator's geographic location

The validator's total stake amount

The validator's commission rate and historical uptime

In a proof-of-stake blockchain, what is staking?

Lending tokens to a DeFi protocol for interest.

Trading tokens on a decentralized exchange.

Locking up tokens to support network security and consensus, in return for rewards.

Sending tokens to a burn address to reduce supply.

In an order book DEX, how is a trade executed?

By swapping tokens directly with a liquidity pool.

By matching a buy order with a sell order at an agreed price.

By the protocol setting a fixed price for each token.

By using an oracle to determine the fair market price.

EC-CouncilBlockchain Developer Certification

Domain 7Objective 5

DeFi Protocols and Their Financial Functions BDC Practice Questions (Page 1)

Part of the Blockchain Security and DeFi Development domain, which makes up ~11% of our current practice bank.

51questions here

11free pages

12concepts

Questions 1–5

1application · medium
A proof-of-stake blockchain allows token holders to delegate their stake to validators. A user delegates to a validator that offers a very high yield but has a history of downtime. What is the primary risk for the user?
Select an answer first
2application · medium
A lending protocol relies on a single price oracle to determine collateral values and trigger liquidations. An attacker manipulates the underlying spot market, causing the oracle to report a falsely low price for a collateral asset, and then liquidates healthy positions at a discount. Which mitigation would be most effective in preventing this type of manipulation?
Select an answer first
3application · medium
A user wants to participate in a proof-of-stake network but does not have enough tokens to run a validator. They decide to delegate their tokens to a validator. What is a key consideration when choosing a validator?
Select an answer first
4foundation · easy
In a proof-of-stake blockchain, what is staking?
Select an answer first
5foundation · easy
In an order book DEX, how is a trade executed?
Select an answer first

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