| 1. | Which of the following circuit breakers has the lowest voltage range ? | |
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SF6 circuit breaker
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Air-break circuit breaker
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lank type oil circuit breaker
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Air-blast circuit breaker
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Report Question| 2. | Which of the following relays is used for protection of motors against overload ? | |
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Buchholz relay
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Electromagnetic attraction type
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Thermal relay
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Impedance relay
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| 3. | Breaking capacity of a circuit breaker is usually expressed in terms of ? | |
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MV A
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volts
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MW
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amperes
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| 4. | ln a circuit breaker the time duration from the instant of the fault to extinction of arc is known as ? | |
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lead time
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clearing time
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lag time
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operation time
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| 5. | ln the event of a fault on connected circuit, a circuit breaker will operate ? | |
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manually through control switch
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automatically
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depends on the design
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manually
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| 6. | A circuit breaker will normally operate ? | |
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when the line is to be checked
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whenever fault in the line occurs
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when the power is to be supplied
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when the switch is put on
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| 7. | A lightning arrester provides ? | |
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a high resistance path between line and ground, during operation
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a low resistance path between line and ground, during operation
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low impedance path between line and ground, during operation
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a high impedance path between line and ground, during operation
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| 8. | Surge modifiers are used to ? | |
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reduce the voltage of wave front
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reduce the current of wave front
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reduce the steepness of wave front
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modify the shape of wave front
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| 9. | Protection by fuses is generally not used beyond ? | |
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100 A
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20 A
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200 A
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50 A
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| 10. | The fuse blows off by ? | |
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arcing
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melting
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burning
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none of the above
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