Power System Protection MCQs Part 21
Contents
- 1 The normal current in power line is 120 A. If short circuit fault occurs on the line, the one can expect the short-circuit current to be
- 2 The fusing current I for a round wire having diameter d is given mathematically by
- 3 Which of the following CB is generally used in railway applications
- 4 A fuse is always connected in
- 5 Arc interruption takes place in oil circuit breaker when
The normal current in power line is 120 A. If short circuit fault occurs on the line, the one can expect the short-circuit current to be
The normal current in power line is 120 A. If short circuit fault occurs on the line, the one can expect the short-circuit current to be:
- 120 A
- 200 A
- 500 A
- More than 1000 A
Correct answer: 4. More than 1000 A
Explanation: The short circuit current is generally more than 10 times of the normal current. Therefore, one can expect the short-circuit current to be more than 1000 A.
The fusing current I for a round wire having diameter d is given mathematically by
The fusing current I for a round wire having diameter d is given mathematically by:
- I ∝ d
- I ∝ d^2
- I ∝ d^3/2
- None of these
Correct answer: 3. I ∝ d^3/2
Which of the following CB is generally used in railway applications
Which of the following CB is generally used in railway applications:
- Air break CB
- Bulk oil CB
- Low oil CB
- SF6 CB
Correct answer: 1. Air break CB
A fuse is always connected in
A fuse is always connected in:
- Series with circuit
- Parallel with circuit
- Series-parallel configuration with circuit
- None of these
Correct answer: 1. Series with circuit
Arc interruption takes place in oil circuit breaker when
Arc interruption takes place in oil circuit breaker when:
- Voltage goes through zero
- Current goes through zero
- Contacts move apparat
- None of these
Correct answer: 2. Current goes through zero
See complete list of Power System Protection MCQs here