1) What is the safety factor of an insulator?
a. Puncture strength * Flash over voltage
b. Puncture strength / Flash over voltage
c. Flash over voltage / Puncture strength
d. None of these
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2) What is the desirable safety factor prescribed for the pin type of insulators?
a. 5
b. 13
c. 10
d. 2
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3) Why is the voltage rating of a multiple shell pin type insulator cannot be increased beyond a limiting value?
a. The internal voltage distribution between shells becomes unequal
b. The leakage path resistance starts reducing
c. The disruptive critical voltage for the material of the insulator is reached
d. The puncture voltage of the material of the insulator is reached
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Answer
Explanation
Related Ques
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ANSWER: The internal voltage distribution between shells becomes unequal
Explanation:
No explanation is available for this question!
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4) What is the main type of distribution system in India?
a. Radial
b. Parallel
c. Network
d. All of these
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5) Which component connects the substation to the area where power is to be distributed?
a. Distributors
b. Service mains
c. Feeders
d. All of these
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6) The cost of material used in a distribution circuit per kVA of the distributed power varies as
a. Square of linear dimensions of supply area.
b. Directly according to (supply area)2
c. Cube of linear dimensions of supply area
d. None of these
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7) Name the cable which connects the distributor to the consumer terminals.
a. Distributors
b. Service mains
c. Feeders
d. All of these
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8) What is the permissible limit of voltage variations allowed in the distribution systems?
a. ± 2 %
b. ± 5 %
c. ± 10 %
d. ± 6 %
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9) Where the radial systems are generally employed?
a. Where power is generated at low voltage
b. Where power is generated at high voltage
c. Where power is generated at low voltage and substation is located at the centre of the load
d. Where power is generated at high voltage and substation is located at the centre of the load
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Answer
Explanation
Related Ques
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ANSWER: Where power is generated at low voltage and substation is located at the centre of the load
Explanation:
No explanation is available for this question!
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10) What is the main advantage of ring main system over radial system?
i. Voltage drop in the feeder is less.
ii. Power factor is higher.
iii. Supply is more reliable.
Which among the above statements are correct?
a. i and ii only
b. ii and iii only
c. i and iii only
d. i, ii and iii
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11) The null point of a uniformly loaded distributor feed at equal voltage at both ends lies at
a. Mid point
b. Either end
c. Two third distance from one end
d. One fourth distance from one end
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12) In a distribution system, which of the following items shares the major cost?
a. Conductors
b. Earthing systems
c. Distribution transformer
d. Insulators
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13) Which type of distribution is preferred in residential areas?
a. Single phase, two wire
b. Three phase, three wire
c. Three phase, four wire
d. Two phase, four wire
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14) In a dc 3 wire distributor using having unequal loads on the two sides
a. Both balancers operate as generators.
b. Both balancers operate as motors.
c. Balancers connected to the lightly loaded sides operate as a generator.
d. Balancers connected to the heavily loaded sides operate as a generator.
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Answer
Explanation
Related Ques
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ANSWER: Balancers connected to the heavily loaded sides operate as a generator.
Explanation:
No explanation is available for this question!
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15) Why are the balancers fields cross connected in a three wire distribution system?
a. Equalise voltage on positive and negative outer
b. Boost the generated voltage
c. Make both machines operate as unloaded motors
d. All of these
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Answer
Explanation
Related Ques
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ANSWER: Equalise voltage on positive and negative outer
Explanation:
No explanation is available for this question!
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16) Which distribution system is energised by two or more generating stations or substations?
a. Radial systems
b. Interconnected systems
c. Ring main systems
d. All of these
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17) A three wire dc distribution makes available how many voltages?
a. One
b. Two
c. Three
d. All of these
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18) If the voltage of the system is about 230 V, then what would be the highest and the lowest permissible voltage?
a. 242 and 214 V
b. 240 and 210 V
c. 244 and 216 V
d. 244 and 212 V
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19) What will be the pd at point B if a pd of 300 V is maintained at a point A, for a 2 wire dc distributor cable AB if 2 km long and supplies loads of 100A, 150A, 200A, and 50A suited at 500m, 1000m, 1600m, and 2000m from the feeding point A. Each conductor has a resistance of 0.01 Ω per 1000 m.
a. 288 V
b. 287.6 V
c. 295.36 V
d. 291.2 V
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20) What is the loss factor in a distribution system?
a. 0.3 * load factor + 0.7 (load factor)2
b. 0.5 * (load factor)
c. Load factor
d. 0.7 * load factor + 0.3 (load factor)2
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21) A 2 wire dc street mains AB, 600 m long is fed from both ends at 220 V. Loads of 20 A, 40 A, 50 A and 30 A are tapped at distances 100m, 250m, 400m and 500m from the end A. If the area of cross section of distributor is 1 cm2, what will be the minimum consumer voltage? If ? = 1.7 * 10-6 Ω cm.
a. 220 V
b. 215.69 V
c. 218.36 V
d. 222.58 V
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22) A distribution system is shown in figure with load currents as marked. The two ends of the feeder are fed by voltage sources such that Vp = Vq = 3 V, the value of the voltage Vp for a minimum voltage of 220 V at any point along the feeder is
a. 225.89 V
b. 222.89 V
c. 220.0 V
d. 228.58 V
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23) A uniformly loaded dc distributor is fed at both ends with equal voltages. In comparison to a similar distributor fed at one end only, what will be the maximum voltage drop?
a. One fourth
b. Half
c. One third
d. One sixth
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24) A uniformly loaded dc distributor is fed at both ends with equal voltages. In comparison to a similar distributor fed at one end only, what will be the drop at the midpoint be?
a. One fourth
b. Half
c. One third
d. One sixth
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25) Installation of capacitors at suitable locations and of optimum size in a distribution system results in
i. Improved voltage regulation.
ii. Reduction in distribution power losses.
iii. Reduction of kVA rating of distribution transformers.
Which among the above statements are correct?
a. i only
b. i and ii only
c. iii only
d. All of these
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26) What are boosters?
a. Is a high voltage and low circuit machine
b. Is a series wound dc generator driven by dc shunt motor
c. Is a low voltage and high current generator operating on straight or linear portion of its voltage current characteristics
d. Both (b) and (c)
e. None of these
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27) Why are the boosters inserted in the circuit?
a. Reduce current
b. Increase current
c. Reduce voltage drop
d. Compensate for voltage drop
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28) Why is the floating neutral in a three phase supply considered as undesirable?
a. High voltage across the load
b. Low voltage across the load
c. Unequal line voltages across the load
d. None of above
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29) A 300m ring distributor has loads as shown in the fig. The distances are in metres. The resistance of each conductor is 0.2 W per 1000 metres and loads are tapped off at B, C, D. If the distributor is fed at A at 240 V, what will be the voltage at B?
a. 220.6 V
b. 236.9 V
c. 240.6 V
d. 235.97 V
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30) For purely domestic loads which type of distribution is employed?
a. Single phase two wire
b. 3 phase 3 wire
c. 3 phase 4 wire
d. None of these
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31) Which type of loads use 3 phase 4 wire ac system of distribution?
a. Balanced
b. Unbalanced
c. Both (a) and (b)
d. None of these
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32) In a balanced 3 phase, 4 wire ac system the phase sequence is RYB. If the voltage of R phase = 230 ∠ 0° volts, then what will be the B phase?
a. 230 ∠ - 120°
b. 230 ∠ - 90°
c. 230 ∠ - 90°
d. 230 ∠ - 120°
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33) What are ground detectors?
a. Used for detecting earth faults for all cables
b. Used for detecting ground faults for underground cables
c. Used for detecting all types of fault in a underground cables
d. None of these
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Answer
Explanation
Related Ques
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ANSWER: Used for detecting ground faults for underground cables
Explanation:
No explanation is available for this question!
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34) A single phase AC distributor supplies two single phase loads as shown. What is the voltage drop from A to C?
a. 4.5 V
b. 30 V
c. 31.5 V
d. 20 V
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35) An industrial consumer has a load pattern of 2000 kW, 0.8 lag for 12 hours and 1000 kW UPF for 12 hours. What is its load factor?
a. 10.5
b. 0.75
c. 0.6
d. 2.0
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36) Where are the strain type of insulators used?
a. Low voltage overhead lines
b. Dead ends
c. Change in direction of the transmission lines
d. Both (b) and (c)
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37) Strain and Shackle type insulators are provided on which type of plane?
a. Vertical plane
b. Horizontal plane
c. On the surface
d. All of these
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38) Which insulator is also called as spool type of insulators?
a. Pin type
b. Shackle type
c. Suspension type
d. Stay insulators
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39) Assembly of which type of insulators are used as strain type of insulators?
a. Pin type
b. Shackle type
c. Suspension type
d. None of these
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40) Which type of insulators is mainly used for low voltage overhead lines?
a. Pin type
b. Shackle type
c. Suspension type
d. None of these
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