Switchgear and Protection MCQs Part 3. Multiple choice questions on Switchgear and Protection.
Contents
- 1 Commonly the making current of the circuit breaker is expressed in terms of
- 2 The rating of fuse is expressed in terms of
- 3 Under normal operating conditions the contacts of the circuit breaker remain
- 4 In case of forced blast circuit breaker, the speed of circuit interruption is
- 5 On switching off the load sparking occurs due to high current
- 6 The circuit breaker must be able to perform the action of
- 7 An isolator is designed to open a circuit under condition of
- 8 If length of the arc in a circuit breaker increases, its resistance
- 9 The time-current graph of a fuse
- 10 For the same power, which of following circuit breaker has least size
Commonly the making current of the circuit breaker is expressed in terms of
Commonly the making current of circuit breaker is expressed in terms of:
- Average value
- Peak value
- RMS value
- None of these
Correct answer: 2. Peak value
The rating of fuse is expressed in terms of
The rating of fuse is expressed in terms of:
- Amperes
- Volts
- Volt-amperes
- kVAR
Correct answer: 1. Amperes
Under normal operating conditions the contacts of the circuit breaker remain
Under normal operating conditions the contacts of the circuit breaker remain:
- Semi-closed
- Closed
- Open
- None of above
Correct answer: 2. Closed
In case of forced blast circuit breaker, the speed of circuit interruption is
In case of forced blast circuit breaker, the speed of circuit interruption is:
- Fast
- Medium
- Slow
- None of these
Correct answer: 1. Fast
On switching off the load sparking occurs due to high current
On switching off the load sparking occurs due to high current:
- Resistance
- Capacitance
- Inductance
- Skin effect
Correct answer: 3. Inductance
The circuit breaker must be able to perform the action of
The circuit breaker must be able to perform the action of:
- Breaking fault current
- Opening faulty circuit
- Carrying fault current for short time
- All of these
Correct answer: 4. All of these
An isolator is designed to open a circuit under condition of
An isolator is designed to open a circuit under condition of:ยท
- Nom1al flow
- Full load
- No load
- None of these
Correct answer: 3. No load
If length of the arc in a circuit breaker increases, its resistance
If length of the arc in a circuit breaker increases, its resistance:
- Increases
- Decreases
- Remains same
- None of above
Correct answer: 1. Increases
The time-current graph of a fuse
The time-current graph of a fuse
- Is a straight line
- Has inverse characteristic
- Is a circle
- None of these
Correct answer: 2. Has inverse characteristic
For the same power, which of following circuit breaker has least size
For the same power, which of following circuit breaker has least size:
- Vacuum circuit breaker
- SF6 circuit breaker
- Oil circuit breaker
- Air-blast circuit breaker
Correct answer: 2. SF6 circuit breaker