Power System Protection MCQ Part 6
The faults which give rise to equal fault currents in the lines having a displacement of 120L are known as
The faults which give rise to equal fault currents in the lines having displacement of 120L are known as:
- Symmetrical faults
- Unsymmetrical faults
Correct answer: 1. Symmetrical faults
Current chopping tendency is minimized by using SF6 gas at
Current chopping tendency is minimized by using SF6 gas at:
- High pressure and high viscosity
- High pressure and low viscosity
- Low pressure and high viscosity
- Low pressure and low viscosity
Correct answer: 4. Low pressure and low viscosity
Which one of following is correct statement about arc voltage in a circuit breaker
Which one of following is correct statement about arc voltage in a circuit breaker:
- It leads arc current by 90L
- It lags arc current by 90L
- It is in phase with arc current
Correct answer: 3. It is in phase with arc current
While designing circuit breakers the value of which of the following factors should be kept low
While designing circuit breakers the value of which of the following factors should be kept low:
- Thermal conductivity
- Thermal capacity
- Contact resistance
Correct answer: 3. Contact resistance
Differential relays are used for the protection of
Differential relays are used for the protection of:
- Alternator
- Feeder
- Transformer
- All of these
Correct answer: 4. All of these