Power System Protection MCQs Part 28

Electrical Engineering MCQs on Power System Protection Part 28

The fuse rating is expressed in terms of

The fuse rating is expressed in terms of

1. Current
2. kVA
3. VAR
4. Voltage

Correct answer: 1. Current

Also see: Top 10 Advantages of Electrical Fuse

An isolator is installed

An isolator is installed

1. Always independent of the position of circuit breaker
2. As a substitute for circuit breaker
3. To operate the relay of circuit breaker
4. Usually on both sides of a circuit breaker

Correct answer: 4. Usually on both sides of a circuit breaker

Also see: Top 10 Differences Between Isolators and Circuit Breakers

Magnetic circuit breaker has

Magnetic circuit breaker has

1. Delayed trip action
2. Instantaneous trip action
3. Both of these
4. None of these

Correct answer: 2. Instantaneous trip action

Also see:

1. Low voltage circuit breakers
2. Medium voltage circuit breakers
3. High voltage circuit breakers

In order to ensure that current should flow without causing excessive heating or voltage drop, the relay contacts should

In order to ensure that current should flow without causing excessive heating or voltage drop, the relay contacts should

1. Be clean and smooth
2. Be of sufficient size and proper shape
3. Have all above properties
4. Have low contact resistance

Correct answer: 3. Have all above properties

Directional relays are based on flow of

Directional relays are based on flow of

1. Current
2. Power
3. Voltage wave
4. All of these

Correct answer: 2. Power

See the working of Directional Overcurrent Protection Relay here