1) What value of DAR ratio indicates a poor insulation?
a. Below 2.5
b. Below 1.25
c. Above 1.25
d. Above 2
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2) Which among these waves is called a standard lightning impulse wave?
a. 1.2 / 100 microsecond wave
b. 1.2 / 50 microsecond wave
c. 2.4 / 100 microsecond wave
d. 2.4 / 50 microsecond wave
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3) Which among these tests is performed to check the dissipation factor?
a. Acceptance tests
b. Periodic maintenance tests
c. Both (a) and (b)
d. Power factor test
e. All the above
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4) What is meant by Creepage Distance?
a. Shortest distance between two conducting parts along a stretched string.
b. Shortest distance between two conducting parts along the surface of the insulating material.
c. Distance between ground and the highest earthed point on the equipment.
d. All of these
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Answer
Explanation
Related Ques
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ANSWER: Shortest distance between two conducting parts along the surface of the insulating material.
Explanation:
No explanation is available for this question!
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5) At what location are the shunt capacitors installed for voltages above 33 kV and above?
a. Are located near the motors
b. Are installed in distribution substations
c. Both (A) and (B)
d. None of these
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6) Which among these HVDC projects are commissioned in India?
a. Rihand – Delhi HVDC
b. Vindhyachal Back to Back only
c. Chandrapur only
d. All of these
e. None of these
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7) Which type of structure is preferred in modern stations?
a. Aluminium alloy structure
b. Galvanised steel structure
c. Fabricated structure
d. All of these
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8) What is the application of hollow porcelain insulator?
a. Transformer bushing
b. Wall bushing
c. SF6 GIS bushing
d. Only b and c
e. All of these
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9) Which types of joints are commonly used to form a string in a string insulator?
a. Ball and socket joint
b. Clevis and tongue coupling
c. Only connector joints
d. Both (a) and (b)
e. All the above
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10) Which equipment is used for EHV lines to improve power transferability?
a. Shunt capacitor
b. Shunt reactor
c. Series capacitor
d. All of these
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11) Which sequence is followed first while closing a circuit breaker?
a. Close the isolator
b. Open earthing switch
c. Close circuit breaker
d. Any of these
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12) Which among these uses a low voltage DC source?
a. Remote indication
b. Emergency lighting system
c. Remote position control
d. All of these
e. None of these
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13) What is the cause for mechanical overloads in the induction motors?
a. Stalling
b. Blowing of fuse
c. Under voltage
d. Open circuit
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14) Which among these synthetic rubber is a thermoplastic?
a. Ethylene propylene rubber
b. Polyvinyl chloride
c. Cross linked poly ethylene
d. All of these
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15) What is the use of belting?
a. To hold the three cores and fillers in a tight assembly
b. To hold the single core and fillers in a tight assembly
c. Is used by only two core assembly
d. Both (A) and (B)
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Answer
Explanation
Related Ques
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ANSWER: To hold the three cores and fillers in a tight assembly
Explanation:
No explanation is available for this question!
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16) At what rated voltage is the shielded cable provided in a low voltage system?
a. Rated voltage < 1kV
b. Rated voltage < 500V
c. Rated voltage > 1 kV
d. Any of these
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17) What data is provided from the no load test on induction motors?
a. Core loss only
b. Magnetising current
c. No load power factor
d. All of these
e. None of these
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18) What is the value of no load current at normal voltage?
a. I0 is between 0.2 and 0.5 pu of full load current
b. I0 is between 0.1 and 0.2 pu of full load current
c. I0 is between 0.4 and 0.9 pu of full load current
d. I0 is between 1 and 1.5 pu of full load current
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Answer
Explanation
Related Ques
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ANSWER: I0 is between 0.2 and 0.5 pu of full load current
Explanation:
No explanation is available for this question!
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19) Which rubber has the properties of natural rubber?
a. Poly chloroprene
b. Ethylene propylene rubber
c. Silicon rubber
d. All of these
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20) Which test is conducted to confirm the withstanding capabilities of insulation?
a. One minute power frequency withstand test
b. Lightning impulse withstand test
c. Switching impulse withstand test
d. All of these
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21) What type of insulated cable is preferred for distribution lines?
a. PVC and XLPE
b. PVC only
c. XLPE only
d. EPR and XLPE
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22) Which among these is a type of catridge?
a. D type
b. Bolted type
c. I type
d. Both (a) and (b)
e. All of these
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23) Upto what temperature should the cable filling compound be warmed for connecting the circuit breaker to the main cable?
a. 80 – 90 ° C
b. 157 – 168 ° C
c. 135 – 148 ° C
d. 149 – 152 ° C
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24) Which among these tests are included in high voltage tests?
a. Power wet test
b. Impulse voltage withstand tests
c. Power frequency withstand test 1 minute dry
d. Only a and b
e. All of these
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25) Which among the following sequence is correct for a synchronous generator?
a. I”d > Id > I’d
b. Id > I’d > I”d
c. I”d > I’d > Id
d. Id > I”d > I’d
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26) What parameter(s) is / are checked using the commissioning tests?
a. Turbine speed
b. Condenser vacuum
c. Turbine governor valve opening
d. Only b and c
e. All of these
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27) At what angle difference is the main winding and the start winding separated in a spilt phase capacitor start induction motor?
a. 45° electrical
b. 90° electrical
c. 45° mechanical
d. 90° mechanical
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28) What is the use of current transformers?
a. Stepping up AC current
b. Measuring and protection
c. Stepping down AC current
d. Both (b) and (c)
e. All of these
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29) What is the typical value of the capacitor used in ‘capacitor start capacitor run’ induction motor?
a. 5 μ F
b. 40 μ F
c. 300 μ F
d. 1000 μ F
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30) Which among these is the application of universal motors?
a. Vacuum cleaners
b. Fans
c. Hair dryers
d. Washing machines
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31) Which type of enclosure is provided for DC motors used in coal handling plants?
a. Screen protected
b. Open type
c. Totally enclosed fan cooled
d. Drip proof
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32) Which among the following applications uses ward Leonard method of speed control?
a. Rolling mills
b. Colliery winding motor
c. Lifts and elevators
d. Only a and c
e. All of these
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33) What is meant by equaliser bus?
a. The bus connecting series fields in parallel
b. The bus connecting series fields in series
c. The bus connecting shunt fields in parallel
d. The bus connecting shunt fields in series
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34) What is the purity of electrically graded aluminium?
a. 95 %
b. 98.3 %
c. 99.5 %
d. 97.5 %
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35) Which alloy is used as electrical resistance alloy?
a. Nickel alloys
b. Nickel chromium alloys
c. Ferro nickel alloys
d. Only a and b
e. All of these
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36) Which material can be used upto a temperature of 130° C?
a. Mica
b. Cotton
c. Synthetic resin
d. All of these
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