Power System Protection Part 10

Power System Protection MCQ Part 10

Power System Protection

What is percentage reactance of a 500 kVA transformer having 5% reactance at 1000 KVA base.

1. 2.5%
2. 5%
3. 10%
4. 20%

Correct answer: 2. 5%

Solution: percentage reactance = Base kVA/Rated kVA*Percentage reactance

The stability of arc in vacuum depends on which of the following factors:

1. Contact material
2. Circuit parameters
3. Both of these
4. None of these

Correct answer: 3. Both of these

Backup protection is primarily intended to:

1. Increase speed
2. Create multiple zones
3. To act in case of failure of primary

Correct answer: 3. To act in case of failure of primary

Admittance relay is:

1. Non-directional relay
2. Directional relay

Correct answer: 2. Directional relay

A fault occurring on the bus itself in a single bus-bar system will result in:

1. Partial shutdown
2. Complete shutdown

Correct answer: 2. complete shutdown