Switchgear protections

1. Wave trap is used to trap waves of

power frequencies
higher frequencies entering generator or transformer units
either of the above
none of the above

Detailed SolutionWave trap is used to trap waves of

2. Circuit breakers are essentially

current carrying contacts called electrodes
arc extinguishers
circuits to break the system
transformers to isolate the two systems E. any of the above

Detailed SolutionCircuit breakers are essentially

3. SF6 gas

Is yellow in colour
Is lighter than air
Is nontoxic
Has pungent small E. None of the above

Detailed SolutionSF6 gas

4. Induction cup relay is operated due to changes in

current
voltage
impedance
all of the above

Detailed SolutionInduction cup relay is operated due to changes in

5. The voltage appearing across the contacts after opening of the circuit breaker is called______voltage.

recovery
surge
operating
arc E. none of the above

Detailed SolutionThe voltage appearing across the contacts after opening of the circuit breaker is called______voltage.

6. A fuse is connected

in series with circuit
in parallel with circuit
either in series or in parallel with circuit
none of the above

Detailed SolutionA fuse is connected

7. Overload relays are of type.

induction
solid state
thermal
electromagnetic E. all above

Detailed SolutionOverload relays are of type.

8. The delay fuses are used for the protection of ________ .

motors
power outlet circuits
fluorescent lamps
light circuits

Detailed SolutionThe delay fuses are used for the protection of ________ .

9. Discrimination between main and back up protection is provided by the use of relays which are

fact
sensitive
slow
none of the above

Detailed SolutionDiscrimination between main and back up protection is provided by the use of relays which are

10. Fault diverters are basically

fuses
relays
fast switches
circuit breakers

Detailed SolutionFault diverters are basically

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