Switchgear Protections

1. A _________ is used to measure the stator % winding temperature of the generator.

1. thermocouple
2. pyrometer
3. resistance thermometer
4. thermometer

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2. A differential relay measures the vector difference between

1. two currents
2. two voltages
3. two or more similar electrical quantities
4. none of the above

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3. A fuse in a motor circuit provides protection against

1. overload
2. short-circuit and overload
3. open circuit, short-circuit and overload
4. none of the above

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4. A fuse is connected

1. in series with circuit
2. in parallel with circuit
3. either in series or in parallel with circuit
4. none of the above

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5. A thermal protection switch can protect against

1. short-circuit
2. temperature
3. overload
4. over voltage

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6. A transmission line is protected by

1. inrush protection
2. distance protection
3. time graded and current graded over current protection
4. both (b) and (c)
5. none of the above

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7. A.C. network analyser is used to solve problems of

1. load flow
2. load flow and short-circuit
3. load flow and stability
4. load flow, short-circuit and stability

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8. Admittance relay is _________ relay.

1. impedance
2. directional
3. non-directional
4. none of the above

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9. Air blast circuit breaker is used for

1. over currents
2. short duty
3. intermittant duty
4. repeated duty

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10. Air blast circuit breakers for 400 kV power system are designed to operate in

1. 100 microsecond
2. 50 millisecond
3. 0.5 sec
4. 0.1 sec

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