Q.76 Earth switch is connected between
    A. line and earth
    B. two lines
    C. line and neutral
    D. circuit breaker and isolators
Ans.: A

Q.77 Which of the following is normally open in substations?
    A. Circuit breaker
    B. Earth switch
    C. Isolators
    D. none of the above
Ans.: B

Q.78 A power transformers are designed to have maximum efficiency ___
    A. at full load
    B. near to full load
    C. Both A or B
    D. at 50% of full load
Ans.: C

Q.79 Power transformers usually designed to make use of flux density of __
    A. 1.5 to 1.77
    B. 0.5 to 1.5
    C. 1 to 1.5
    D. 0.5 to 7.7
Ans.: A

Q.80 The voltage regulation of power transformer is ranging from___
    A. 5 to 8%
    B. 6-10%
    C. 10-12%
    D. 10-15%
Ans.: B

Q.81 The control system in substations generally operated at__
    A. 110V
    B. 220 V
    C. Both A or B
    D. 400V
Ans.: C

Q.82 Carrier current equipment is installed in substations for___
    A. relaying
    B. Communication
    C. Telemetering or supervisory control
    D. all of the above
Ans.: D

Q.83 The indicating and metering instruments used in substations are___
    A. Ammeters, Voltmeters
    B. Wattmeter, power factor meters
    C. KWh and KVARh meters
    D. all of the above
Ans.: D

Q.84 Batteries are used in substation for the purpose of__
    A. emergency lighting
    B. to supply operating and control circuits
    C. to supply protective relaying systems
    D. all of the above
Ans.: D

Q.85 Which of the following is closed after line is disconnected from the supply?
    A. isolators
    B. Earth switch
    C. Circuit breakers
    D. relays
Ans.: B

Q.86 Which of the following is closed first for supplying power after repairs or maintenance?
    A. isolators
    B. Earth switch
    C. Circuit breakers
    D. relays
Ans.: A

Q.87 Which of the following is secondary transmission voltage?
    A. 66 KV
    B. 33 KV
    C. 400 KV
    D. Both A or B
Ans.: D

Q.88 Which of the following is primary transmission voltage?
    A. 132 KV
    B. 400KV
    C. 765 KV
    D. all of the above
Ans.: D

Q.89 Which of the following is remains open during normal operation of power system?
    A. Earth switch
    B. Circuit breaker
    C. Isolators
    D. indicating instruments
Ans.: A

Q.90 A charging current is discharge through_____ after the line is disconnected from the main supply?
    A. Earth switch
    B. Circuit breaker
    C. Isolators
    D. indicating instruments
Ans.: A