Objective Type Question or MCQ of Power System Protection page-1

1.In a circuit breaker, are is initiated by the process of

a) Thermal emission
b) Alternators
c) Field emission
d) Transmission lines

Ans: (d)

2. Bulk oil circuit breaker is suitable for voltages upto

a) 4 kV
b) 25 kV
c) 10 kV
d) 36 kV

Ans: (d)

3. Circuit breakers are essentially

a) Current carrying contacts called electrodes
b) Arc extinguishers
c) Transformers to isolate two systems
d) Circuits to break the system

Ans: (a)

4. The voltage across the circuit breaker pole after final current zero is

a) Restriking voltage
b) Supply voltage
c) Recovery voltage
d) None of these

Ans: (c)

5. Which of the following circuit breakers takes minimum time installation?

a) Bulk oil circuit breaker
b) Minimum oil circuit breaker
c) Air blast circuit breaker
d) SF₆ circuit breaker

Ans: (d)

6. In a power system, the rate of rise of restriking voltage depends upon

a) Circuit power factor only
b) Switching condition only
c) Both (a) and (b) above
d) None of these

Ans: (c)

7. In a circuit breaker, the arcing contents are made of

a) Aluminium
b) Electrolytic
c) Copper tungsten alloy
d) Tungsten

Ans: (c)

8. Fault diverters are basically

a) Circuit breakers
b) Fast switches
c) Relays
d) Fuses

Ans: (b)

9. The following medium is employed for extinction of arc in air break circuit breakers?

a) Air
b) Oil
c) Water
d) None of these

Ans: (a)

10. The following circuit breaker does not use pneumatic operating mechanism

a) Air break circuit breaker
b) Air blast circuit breaker
c) Bulk oil circuit breaker
d) SF₆ circuit breaker

Ans: (c)

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