Power System Protection MCQ Part 9

Power System Protection MCQ Part 9

Power System Protection

Arc resistance can be increased by:

1. Splitting the arc
2. Reducing its length
3. Increasing its diameter
4. Increasing concentration of ionized particles

Correct answer: 1. Splitting the arc

Inverse time-current relays are not used for protection of:

1. Alternators
2. Feeders
3. Transformers
4. All of above

Correct answer: 1. Alternators

Short circuit current limiting reactors may be connected to which of the following locations:

1. In series with each generator
2. In series with each feeder
3. Bus-bars
4. All of these

Correct answer: 4. All of these

The operator ‘a’ in symmetrical current theory when multiplied to a vector rotates the vector through:

1. 0L
2. 45L
3. 90L
4. 120L

Correct answer: 4. 120L

Reactance realay is normally employed for protection against:

1. Earth fault
2. Phase fault

Correct answer: 1. Earth fault