# Maintenance & Testing of Electrical Equipments Test Set 3

1)   What is the average value of a lead acid cell?

a. 1.2 V (DC)
b. 2.2 V (DC)
c. 1.8 V (DC)
d. 2.5 V (DC)
 Answer  Explanation  Related Ques ANSWER: 1.8 V (DC) Explanation: No explanation is available for this question!

2)   Which among the following components is / are present in the auxiliary AC system?

a. High voltage and low voltage switchgear
b. Power cables
d. All of these
e. None of these
 Answer  Explanation  Related Ques ANSWER: All of these Explanation: No explanation is available for this question!

3)   Which alarm is generally used in a DC bus?

a. Over voltage alarm
b. Earth fault alarm
c. Under voltage alarm
d. Only (b) & (c)
e. All of these
 Answer  Explanation  Related Ques ANSWER: All of these Explanation: No explanation is available for this question!

4)   Which charging method is preferred to avoid sulphating of batteries?

a. Initial charging
b. Trickle charging
c. Quick charging
d. All of these
 Answer  Explanation  Related Ques ANSWER: Trickle charging Explanation: No explanation is available for this question!

5)   What is main cause of sulphating?

a. Partial charging
b. Discharged for longer period
c. High specific gravity
d. Only (a) & (b)
e. All of these
 Answer  Explanation  Related Ques ANSWER: All of these Explanation: No explanation is available for this question!

6)   What is the equation for kW rating calculation in a battery charger using taper method?

a. kW = (N* Ah * 2.25 *0.225 * 0.8 ) / 1000
b. kW = (N* Ah * 0.25 *0.225 * 0.8 ) / 1000
c. kW = (N* Ah * 2.25 *0.225 * 0.6 ) / 1000
d. kW = (N* Ah * 2.25 *0.225 * 1.8 ) / 1000
 Answer  Explanation  Related Ques ANSWER: kW = (N* Ah * 2.25 *0.225 * 0.8 ) / 1000 Explanation: No explanation is available for this question!

7)   What is the maximum temperature of the electrolyte in case of nickel cadmium battery?

a. 10 °
b. 25 °
c. 46 °
d. 60 °
 Answer  Explanation  Related Ques ANSWER: 46 ° Explanation: No explanation is available for this question!

8)   Which substance is generally added to prevent contamination of electrolyte?

a. Transformer oil
b. Paraffin oil
c. A small piece of zinc
d. None of these
 Answer  Explanation  Related Ques ANSWER: Paraffin oil Explanation: No explanation is available for this question!

9)   What is the main cause of noise in the transformer?

a. Magnetostriction
b. Mechanical vibration of the tank
c. Mechanical vibration due to lamination
d. Only (a) & (c)
e. All of these
 Answer  Explanation  Related Ques ANSWER: All of these Explanation: No explanation is available for this question!

10)   Which measuring is used for the measurement of insulation resistance?

a. Kelvin’s bridge
b. Wheatstone bridge
c. Megger
d. Both (b) and (c)
 Answer  Explanation  Related Ques ANSWER: Megger Explanation: No explanation is available for this question!

11)   What is polarisation index?

a. Ratio of 10 minute resistance to one minute insulation resistance
b. Ratio of 1 minute resistance to 10 minute insulation resistance
c. Ratio of 5 minute resistance to 25 minute insulation resistance
d. None of these
 Answer  Explanation  Related Ques ANSWER: Ratio of 10 minute resistance to one minute insulation resistance Explanation: No explanation is available for this question!

12)   What is the maximum temperature limit up to which class E insulation can be used?

a. 120 °C
b. 180 °C
c. 50 °C
d. 90 °C
 Answer  Explanation  Related Ques ANSWER: 120 °C Explanation: No explanation is available for this question!

13)   Which method of connection is preferred for VTs?

a. V – V connection
b. Star – star connection
c. Star - open delta
d. All of these
e. None of these
 Answer  Explanation  Related Ques ANSWER: All of these Explanation: No explanation is available for this question!

14)   What is the application of capacitor voltage transformers?

a. Line voltmeters
b. Protective relays
c. High speed distance protection
d. Both (a) and (b)
e. All of these
 Answer  Explanation  Related Ques ANSWER: Both (a) and (b) Explanation: No explanation is available for this question!

15)   What is the accuracy class of residually connected VT?

a. 5.00 or 10.00
b. 6.00 or 12.00
c. 4.00 or 8.00
d. 10.00 or 20.00
 Answer  Explanation  Related Ques ANSWER: 5.00 or 10.00 Explanation: No explanation is available for this question!

16)   What is the residual voltage in VT?

a. Vector sum of three line to line voltages
b. Vector sum of three line to earth voltage
c. Vector sum of three phase voltage
d. None of these
 Answer  Explanation  Related Ques ANSWER: Vector sum of three line to earth voltage Explanation: No explanation is available for this question!

17)   Insulation resistance of H V circuit breaker is more than ___________.

a. 1000 M Ω
b. 500 M Ω
c. 2000 M Ω
d. 400 M Ω
 Answer  Explanation  Related Ques ANSWER: 2000 M Ω Explanation: No explanation is available for this question!

18)   What is the main application of single phase circuit breaker?

a. In power generating station
b. On the roof of coach
c. Both (a) and (b)
d. On the distribution system
 Answer  Explanation  Related Ques ANSWER: On the roof of coach Explanation: No explanation is available for this question!

19)   Which among the following is present in SCADA?

a. Data collection equipment
b. Data transmission telemetric equipment
c. Data monitoring equipment
d. All of these
e. None of these
 Answer  Explanation  Related Ques ANSWER: All of these Explanation: No explanation is available for this question!

20)   Which instrument is present in the power line carrier communication system?

a. Multiplexer
b. Tuning unit
d. None of these
 Answer  Explanation  Related Ques ANSWER: Tuning unit Explanation: No explanation is available for this question!

21)   What is present in relay maintenance unit?

a. Foreign matter removal
b. Covers cleaning
c. Breakers tripped by manual contact closing
d. All of these
e. None of these
 Answer  Explanation  Related Ques ANSWER: All of these Explanation: No explanation is available for this question!

22)   Which equipments are installed in the main substation?

a. Auxiliary switchgear
b. Low voltage AC switchgear
c. Low voltage DC switchgear
d. Only (a) & (b)
e. All of these
 Answer  Explanation  Related Ques ANSWER: All of these Explanation: No explanation is available for this question!

23)   What does the numerical in ‘IC 11‘ indicate?

a. First numerical indicates the machine is free air circulation.
Second numerical indicates that the coolant is self circulated.
b. First numerical indicates that the coolant is self circulated.
Second numerical indicates the machine is free air circulatio
c. First numerical indicates the machine is free air circulation.
Second numerical indicates that the coolant is circulated by integrally mounted component.
d. First numerical indicates that the coolant is circulated by integrally mounted component.
Second numerical indicates the machine is free air circulation.
 Answer  Explanation  Related Ques ANSWER: First numerical indicates the machine is free air circulation. Second numerical indicates that the coolant is self circulated. Explanation: No explanation is available for this question!

24)   What is meant by circulation by integral dependent component?

a. Movement of the coolant by temperature difference.
b. Movement of the coolant by means of an integral component not mounted directly on the shaft of the machine.
c. Movement of the coolant by an electrical or mechanical intermediate component mounted on the machine.
d. None of these.
 Answer  Explanation  Related Ques ANSWER: Movement of the coolant by means of an integral component not mounted directly on the shaft of the machine. Explanation: No explanation is available for this question!

25)   What is the description for W in ‘IC W 37A71’?

a. Water circulated by separate pump.
b. Forced water cooled machine.
c. Water cooled heat exchanger on the machine.
d. Both A and C
 Answer  Explanation  Related Ques ANSWER: Both A and C Explanation: No explanation is available for this question!

26)   What is meant by submersible machine?

a. Water from heavy seas shall not enter the machine in harmful quantity.
b. Ingress of water into the machine in a harmful quantity shall not be possible when the machine is immersed in water.
c. Water splashed against the machine from any direction shall have no harmful effect.
d. None of these
 Answer  Explanation  Related Ques ANSWER: Ingress of water into the machine in a harmful quantity shall not be possible when the machine is immersed in water. Explanation: No explanation is available for this question!

27)   What is / are the criteria used for choosing different types of frame for rotary electrical machines?

a. The bearing type
b. The form of stator
c. The position of shaft
d. All of these
 Answer  Explanation  Related Ques ANSWER: All of these Explanation: No explanation is available for this question!

28)   Which among these is not a type of single phase AC motor?

a. Split phase
b. Synchronous motor
c. Capacitor start
d. Capacitor run
 Answer  Explanation  Related Ques ANSWER: Synchronous motor Explanation: No explanation is available for this question!

29)   Which of the standards are applicable for designing induction motors?

a. Indian standards
b. British standards
c. International electro technical commissions standards
d. All of these
e. None of these
 Answer  Explanation  Related Ques ANSWER: All of these Explanation: No explanation is available for this question!

30)   What designation is used for non sparking type of motor?

a. Ex(d)
b. Ex(p)
c. Ex(N)
d. Ex(e)
 Answer  Explanation  Related Ques ANSWER: Ex(N) Explanation: No explanation is available for this question!

31)   What is the polarization index value for a class A type insulation?

a. 1.5
b. 2.0
c. 2.5
d. Less than 1
 Answer  Explanation  Related Ques ANSWER: 1.5 Explanation: No explanation is available for this question!

32)   What is meant by ‘consign’?

a. The person to whom the material is to be delivered
b. To entrust the material to carrier for delivery
c. By whom the material has been sent
d. None of these
 Answer  Explanation  Related Ques ANSWER: To entrust the material to carrier for delivery Explanation: No explanation is available for this question!

33)   Which among these is the basic requirement of machine foundation?

a. Horizontal level
b. Rigidity
c. Freedom from vibrations
d. Only (b) & (c)
e. All of these
 Answer  Explanation  Related Ques ANSWER: All of these Explanation: No explanation is available for this question!

34)   What will be the rating of heater if the machine to be dried is less than 500 kW?

a. 1.5 - 3 % of the machine rating
b. 3.5 % of the machine rating
c. 5 % of the machine rating
d. 5.5 % of the machine rating
 Answer  Explanation  Related Ques ANSWER: 3.5 % of the machine rating Explanation: No explanation is available for this question!

35)   Why are the high voltage test conducted on the rotating machine?

a. To check the winding resistance
b. To check the insulation of windings
c. To check the maximum power rating of the machine
d. All of these
e. None of these
 Answer  Explanation  Related Ques ANSWER: To check the insulation of windings Explanation: No explanation is available for this question!

36)   What is the expression for maximum test voltage for conducting site tests?

a. Vac = 1.5 * rated line to line voltage
b. Vac = 2 * rated line to line voltage
c. Vac = 3 * rated line to line voltage
d. Vac = rated line to line voltage
 Answer  Explanation  Related Ques ANSWER: Vac = 1.5 * rated line to line voltage Explanation: No explanation is available for this question!

37)   What will be the voltage applied in a routine test for 1minute if the rated voltage of the electrical machine is 400 V?

a. 400 V
b. 1000 V
c. 2000 V
d. 3000 V
 Answer  Explanation  Related Ques ANSWER: 2000 V Explanation: No explanation is available for this question!

38)   What will be the maximum permissible difference in resistance from the measured value to the manufacturer’s value?

a. ± 3 %
b. ± 2 %
c. ± 5 %
d. ± 1 %
 Answer  Explanation  Related Ques ANSWER: ± 2 % Explanation: No explanation is available for this question!

39)   Which power factor condition is not suitable for the operation of synchronous generator?