# Basic Electrical Engineering Test - Set - 3

1)   “ Total electric flux through any closed surface is equal to the charge enclosed by that surface ”. This is

a. Lenz’s law
b. Gauss’s law
c. Maxwell’s law
 Answer  Explanation  Related Ques ANSWER: Gauss’s law Explanation: No explanation is available for this question!

2)   Gauss’s law is applicable for

a. Only point charge
b. Infinite line charge
c. Infinite sheet of charge
d. All of these
 Answer  Explanation  Related Ques ANSWER: All of these Explanation: No explanation is available for this question!

3)   The potential difference between two points is given by

a. V = E / Q
b. V = W / Q
c. V = Q / E
d. V = Q / W
 Answer  Explanation  Related Ques ANSWER: V = W / Q Explanation: No explanation is available for this question!

4)   For forming an electric dipole between two point charges separated by a small distance, the two point charges are of

a. Unequal magnitude and opposite sign
b. Unequal magnitude but same sign
c. Equal magnitude and same sign
d. Equal magnitude but opposite sign
 Answer  Explanation  Related Ques ANSWER: Equal magnitude but opposite sign Explanation: No explanation is available for this question!

5)   The amount of work done in moving a charge from one point to another along an equipotential line or surface charge is

a. Zero
b. Infinity
c. One
d. Two
 Answer  Explanation  Related Ques ANSWER: Zero Explanation: No explanation is available for this question!

6)   In ac circuitμ the maximum current required is

a. Equal to the effective current
b. 1.414 times the effective current
c. Twice the effective current
d. 1.732 times the effective current
 Answer  Explanation  Related Ques ANSWER: 1.414 times the effective current Explanation: No explanation is available for this question!

7)   A vector quantity has

a. Only magnitude
b. Only direction
c. Both (a) and (b)
d. None of these
 Answer  Explanation  Related Ques ANSWER: Both (a) and (b) Explanation: No explanation is available for this question!

8)   The phasor current through a 200 ohm resistor assuming a voltage of 200Arms at an angle of zero degree applied across it is

a. 1Arms at an angle of zero degree
b. 1Arms at an angle of 45 degree
c. 1Arms at an angle of 90 degree
d. 1Arms at an angle of 180 degree
 Answer  Explanation  Related Ques ANSWER: 1Arms at an angle of zero degree Explanation: No explanation is available for this question!

9)   If the number of turns, area and current of an ac circuit is doubled then the new inductance will be

a. Equal to the former
b. Twice of the former
c. Four times the former
d. Half of the former
 Answer  Explanation  Related Ques ANSWER: Four times the former Explanation: No explanation is available for this question!

10)   When an ac power is applied to a reactive load, then the voltage is

a. In phase with the current
b. 90 degree out of phase with the current
c. 180 degree out of phase with the current
d. 270 degree out of phase with the current
 Answer  Explanation  Related Ques ANSWER: 90 degree out of phase with the current Explanation: No explanation is available for this question!

11)   If the number of conductors and speed of a lap wound generator is doubled then the generated emf will be

a. Remains same
b. Twice of the former
c. Four times of former emf
d. Half of the former emf
 Answer  Explanation  Related Ques ANSWER: Four times of former emf Explanation: No explanation is available for this question!

12)   When the motor runs on no load, then

a. Back emf is almost equal to applied voltage
b. Back emf will be greater than applied voltage
c. Back emf will be less than applied voltage
d. None of these
 Answer  Explanation  Related Ques ANSWER: Back emf is almost equal to applied voltage Explanation: No explanation is available for this question!

13)   The field winding of dc series motor consists of few turns of

a. Thin wire with low resistance
b. Thick wire with low resistance
c. Thin wire with high resistance
d. Thick wire with high resistance
 Answer  Explanation  Related Ques ANSWER: Thick wire with low resistance Explanation: No explanation is available for this question!

14)   If the armature current of dc series motor has become twice then the torque will become

a. Twice of the former
b. Four times of the former
c. One fourth of the former
d. Remains same
 Answer  Explanation  Related Ques ANSWER: Four times of the former Explanation: No explanation is available for this question!

15)   For application in electric locomotives or for traction purposes, the most suitable motor is

a. Dc series motor
b. Differentially compounded motor
c. Cumulatively compounded motor
d. None of these
 Answer  Explanation  Related Ques ANSWER: Dc series motor Explanation: No explanation is available for this question!

16)   In order to bring the pointer to rest within a short time,

a. Gravity control is required
b. Damping control is required
c. Spring control is required
d. All of these
 Answer  Explanation  Related Ques ANSWER: Damping control is required Explanation: No explanation is available for this question!

17)   Among the following damping method, the most effective and efficient damping is

a. Air friction damping
b. Fluid friction damping
c. Eddy current damping
d. None of these
 Answer  Explanation  Related Ques ANSWER: Eddy current damping Explanation: No explanation is available for this question!

18)   In dynamometer type wattmeter, at equilibrium

a. Tc > Td
b. Tc < Td
c. Tc = Td
d. None of these
 Answer  Explanation  Related Ques ANSWER: Tc = Td Explanation: No explanation is available for this question!

19)   The moving system of induction type single - phase energy meter consists of

a. One pointer and two control spring
b. One pointer and one control spring
c. Two pointer and two control spring
d. No pointer and no control spring
 Answer  Explanation  Related Ques ANSWER: No pointer and no control spring Explanation: No explanation is available for this question!

20)   The braking torque of induction type single - phase energy meter is

a. Directly proportional to the flux
b. Inversely proportional to the flux
c. Directly proportional to the square of the flux
d. Inversely proportional to the square of the flux
 Answer  Explanation  Related Ques ANSWER: Directly proportional to the square of the flux Explanation: No explanation is available for this question!

21)   The power curve for a purely resistive circuit is zero only when

a. Current is zero
b. Voltage is zero
c. Both current and voltage is zero
d. None of these
 Answer  Explanation  Related Ques ANSWER: Both current and voltage is zero Explanation: No explanation is available for this question!

22)   The power absorbed by a pure inductive circuit and pure capacitive circuit is

a. Zero and non zero
b. Non zero and zero
c. Non zero and non zero
d. Zero and zero
 Answer  Explanation  Related Ques ANSWER: Zero and zero Explanation: No explanation is available for this question!

23)   The product of rms values of current and voltage is called as

a. Real power
b. Apparent power
c. Reactive power
d. Polar curves
 Answer  Explanation  Related Ques ANSWER: Apparent power Explanation: No explanation is available for this question!

24)   The net power in a series R-C circuit is

a. Zero
b. Positive
c. Negative
d. None of these
 Answer  Explanation  Related Ques ANSWER: Positive Explanation: No explanation is available for this question!

25)   For solving parallel ac circuit, the method used is

a. Vector method
c. Symbolic or j - method
d. All of these
 Answer  Explanation  Related Ques ANSWER: All of these Explanation: No explanation is available for this question!

26)   For improving the soil condition and efficiency of earthing system, the pit area around the G.I. pipe is filled with

a. Mixture of copper and nickel
b. Mixture of chloride and sodium
c. Mixture of aluminium and sulphate
d. Mixture of salt and coal
 Answer  Explanation  Related Ques ANSWER: Mixture of salt and coal Explanation: No explanation is available for this question!

27)   The fusing current of a fuse depends on its

a. Material and its length
b. Length and its diameter
c. Material and diameter
d. Material, length and diameter
 Answer  Explanation  Related Ques ANSWER: Material, length and diameter Explanation: No explanation is available for this question!

28)   The wrong statement among the following is

a. A fuse can be fitted in an outlet socket
b. A fuse should not get overheated
c. The current rating of fuse should not exceed the rating of the smallest cable protected
d. Fuse having rating less than 3 A can be used in radio
 Answer  Explanation  Related Ques ANSWER: A fuse can be fitted in an outlet socket Explanation: No explanation is available for this question!

29)   In HRC fuses, the space within the body surrounding the element is usually filled with

a. Silver
b. Zinc
c. Quartz
d. Copper
 Answer  Explanation  Related Ques ANSWER: Quartz Explanation: No explanation is available for this question!

30)   For extinguishing arc in an high voltage fuses, the element can be immersed in

a. Oil
b. Carbon tetrachloride
c. Carbon tetrafloride
d. Only (a) and (b)
 Answer  Explanation  Related Ques ANSWER: Only (a) and (b) Explanation: No explanation is available for this question!

31)   The expression for total power output of a delta connected system in terms of phase voltage and current is given by

a. 3VpIpcos∅
b. √3VpIpcos∅
c. 1/√ 3VpIpcos∅
d. 1/3 x VpIpcos∅
 Answer  Explanation  Related Ques ANSWER: 3VpIpcos∅ Explanation: No explanation is available for this question!

32)   In delta connected system, the potential difference between line outers is

a. Equal to the phase voltage
b. Greater than the phase voltage
c. Less than the phase voltage
d. None of these
 Answer  Explanation  Related Ques ANSWER: Equal to the phase voltage Explanation: No explanation is available for this question!

33)   By using two wattmeter method, power can be measured in

a. 3 - phase, 2 - wire system
b. 3 - phase, 3 - wire system
c. 3 - phase, 4 - wire system
d. All of these
 Answer  Explanation  Related Ques ANSWER: 3 - phase, 3 - wire system Explanation: No explanation is available for this question!

34)   The two wattmeter method is applicable for

a. Only star connected system
b. Only delta connected system
c. Both star connected and delta connected system
d. None of these
 Answer  Explanation  Related Ques ANSWER: Both star connected and delta connected system Explanation: No explanation is available for this question!

35)   In a balanced 3-phase system, if one of the two wattmeter’s reading is negative then the

a. Reading should be taken as it is
b. Reading should be taken after reversing the pressure coil
c. Reading should be taken after reversing the current coil
d. All of these
 Answer  Explanation  Related Ques ANSWER: Reading should be taken after reversing the pressure coil Explanation: No explanation is available for this question!

36)   From full load to no load, the change of terminal voltage is more in case of

a. Lagging power factor
c. Unity power factor
d. Both lagging and leading power factor compared to unity power factor
 Answer  Explanation  Related Ques ANSWER: Both lagging and leading power factor compared to unity power factor Explanation: No explanation is available for this question!

37)   The synchronous generator is also called an

a. AC generator
b. Alternator
c. DC generator
d. Only (a) and (b)
 Answer  Explanation  Related Ques ANSWER: Only (a) and (b) Explanation: No explanation is available for this question!

38)   In India, the synchronous generator generates

a. 11 kilo - volts
b. 33 kV
c. 66 kV
d. Either (a) or (b)
 Answer  Explanation  Related Ques ANSWER: Either (a) or (b) Explanation: No explanation is available for this question!

39)   The non salient pole type synchronous generator is driven by

a. Hydraulic turbines
b. Diesel engines
c. Steam engines
d. All of these
 Answer  Explanation  Related Ques ANSWER: Steam engines Explanation: No explanation is available for this question!

40)   The number of cycles of the induced emf per second is equal to

a. No. of cycles per revolutions x no. of revolutions per second
b. No. of cycles per second x no. of revolutions per second
c. No. of cycles per revolutions x no. of revolutions per hour
d. No. of cycles per revolutions / no. of revolutions per second
 Answer  Explanation  Related Ques ANSWER: No. of cycles per revolutions x no. of revolutions per second Explanation: No explanation is available for this question!

41)   Copper losses occurs due to ohmic resistance in

a. Primary winding
b. Secondary winding
c. Both primary and secondary winding
d. None of these
 Answer  Explanation  Related Ques ANSWER: Both primary and secondary winding Explanation: No explanation is available for this question!

42)   Efficiency of a transformer is maximum at

b. Lagging power factor
c. Unity power factor
d. None of these
 Answer  Explanation  Related Ques ANSWER: Unity power factor Explanation: No explanation is available for this question!

43)   If the transformer is loaded then the secondary terminal voltage falls for and rises for

a. Lagging power factor, leading power factor
b. Lagging power factor, unity power factor
c. Unity power factor, lagging power factor
d. Leading power factor, lagging power factor
 Answer  Explanation  Related Ques ANSWER: Lagging power factor, leading power factor Explanation: No explanation is available for this question!

44)   Copper losses is proportional to

a. kVA
b. square of kVA
c. cube of kVA
d. none of these
 Answer  Explanation  Related Ques ANSWER: square of kVA Explanation: No explanation is available for this question!

45)   The efficiency of the transformer will be maximum when

a. Iron losses is equal to the twice of the copper losses
b. Copper losses is equal to the twice of the iron losses
c. Iron losses is equal to the copper losses
d. All of these
 Answer  Explanation  Related Ques ANSWER: Iron losses is equal to the copper losses Explanation: No explanation is available for this question!

46)   The frequency of the induced emf in an induction motor is

a. Greater than the supply frequency
b. Lesser than the supply frequency
c. Same as the supply frequency
d. None of these
 Answer  Explanation  Related Ques ANSWER: Same as the supply frequency Explanation: No explanation is available for this question!

47)   In an induction motor, rotor speed is always

a. Less than the stator speed
b. More than the stator speed
c. Equal to the stator speed
d. None of these
 Answer  Explanation  Related Ques ANSWER: Less than the stator speed Explanation: No explanation is available for this question!

48)   Slip of an induction motor increases with

a. increase in current and decrease in torque
b. increase in current and torque
c. decrease in current and torque
d. decrease in current and increase in torque
 Answer  Explanation  Related Ques ANSWER: increase in current and torque Explanation: No explanation is available for this question!

49)   The frequency of rotor current in an induction motor is

a. slip times the frequency of stator current
b. slip times the frequency of supply
c. One by slip times the frequency of stator current
d. One by slip times the frequency of supply
 Answer  Explanation  Related Ques ANSWER: slip times the frequency of supply Explanation: No explanation is available for this question!

50)   Slip ring induction motor has

a. Low starting torque
b. Medium starting torque
c. High starting torque
d. None of these
 Answer  Explanation  Related Ques ANSWER: High starting torque Explanation: No explanation is available for this question!