# 125+ Single-Phase Induction Motors Multiple Choice Questions (MCQ)

In this article, we shared the single-phase induction motors multiple choice questions and answers for electrical and electronics engineers.

## Single-Phase Induction Motors Multiple Choice Questions

The below list provides all the multiple-choice questions related to the electrical induction motors.

Answers are available at the bottom of the article.

1. The direction of rotation of a shaded pole motor is determined by

2. As hysteresis motors are free from mechanical and magnetic vibrations, therefore, these are considered as suitable for

3. The value of starting capacitor of a fractional horse-power motor will be

4. Which of the following motors is used for the unity power factor?

5. The speed control of universal motor used for sewing machines is by

6. Speed torque characteristic of a repulsion induction motor is similar to that of a D.C.

7. The purpose of the stator winding in the compensated repulsion motor is to

8. When a D.C. series motor is connected to A.C. supply, the power factor will be low- because of

9. Which of the following statements regarding reluctance-start motor is incorrect ?

10. What could be the size of a universal motor for use in vacuum cleaners?

11. The centrifugal switch is used to disconnect starting winding when the motor has

12. Which of the following motor will have a relatively higher power factor?

13. The range of efficiency for shaded pole motors is

14. For ceiling fans generally the single-phase motor used is

15. If starting winding of a single-phase induction motor is left in the circuit, it will

16. A reluctance motor

17. In a hysteresis motor, the rotor must have

18. Which motor will make the least noise?

19. Shading coils, in case of a shaded pole motor, are used to

20. If a D.C. series motor is operated on an A.C. supply, it will

21. In repulsion motor, maximum torque is developed when

22. In A.C. series motor compensating winding is employed to

23. A.C. series motor as compared to D.C. series motor has

24. In a shaded pole motor, the shading coil usually consist of

25. Centrifugal switch disconnects the auxiliary winding of the motor at about ____percent of synchronous speed

26. Reluctance motors are

27. A schrage motor can run on

28. Short-circuiter is used in

29. Which of the following motors would you select for vacuum cleaners?

30. Speed control of a universal motor is achieved by

31. In a split-phase motor the ratio of the number of turns for starting winding to that for running winding is

32. A repulsion-start induction-run single phase motor runs as an induction motor only when

33. A universal motor is one which

34. A shaded pole motor does not possess

35. The electric motor used in portable drills is

36. If the centrifugal switch of a two-value capacitor motor using two capacitors fails to open then

37. If a particular application needs high speed and high starting torque, then which of the following motor will be preferred?

38. If a single-phase motor runs hot the probable cause cannot be

39. Electrical faults in a motor occur most commonly in its

40. A universal motor operates on

41. Which of the following applications would need the smallest size of motor?

42. Which of the following statements regarding permanent-split single value capacitor motor is incorrect?

43. Which motor is relatively free from mechanical and magnetic vibrations?

44. A single-phase induction motor is

45. If the centrifugal switch does not open at 70 to 80 percent of the synchronous speed of the motor, it would result in

46. For which of the applications a reluctance motor is preferred?

47. Direction of rotation of a split-phase motor can be reversed by reversing the connection of

48. In a capacitor start single-phase motor when the capacitor is replaced by a resistance

49. In split-phase motor main winding is of

50. In case of high speed universal motor which of the following needs more attention ?

51. The wattage of the motor for driving a domestic sewing machine will be around

52. By pushing and pulling the rotor shaft of a motor, we can check its

53. Two-value capacitor motor finds increased application as compressor motor in small home air conditioners because

54. A capacitor selected for capacitor-run motor should be rated for

55. In which single-phase motor, the rotor has no teeth or winding?

56. The wattage rating for a ceiling fan motor will be in the range

57. Which of the following applications make use of a universal motor?

58. Which of the following statements regarding a reluctance motor is incorrect?

59. The speed with which the magnetic field of an induction motor rotates is called

60. Which of the following motors has the highest starting torque?

61. Starting winding of a single-phase motor of a refrigerator is disconnected from the circuit by means of a

62. In a shaded pole motor, the direction of rotation is from

63. Which of the following single-phase induction motors is generally used in time phonographs?

64. When a universal motor is operated on no-load, its speed is limited by

65. Most of the fractional horsepower motors have either

66. In a split phase motor

67. If the ceiling fan, when switched on, runs at a slow speed in the reverse direction, it can be concluded that

68. The rotor of the hysteresis motor is made of

69. The motor used for the compressors is

70. Which motor is normally free from mechanical and magnetic vibrations?

71. In a split phase motor, the running winding should have

72. The speed of a universal motor is generally reduced by using

73. A hysteresis motor works on the principle of

74. In an A.C. series motor armature coils are usually connected to the commutator

75. The capacitors used in, single-phase capacitor motors have no

76. In a ceiling fan employing capacitor run motor

77. The starting winding of a single-phase motor is placed in

78. Which of the following motors has two separate windings on the motor?

79. A shaded pole motor can be used for

80. A single-phase capacitor-start motor will take starting current nearly

81. The direction of rotation of the universal motor can be reversed by

82. In a universal motor, normally the ratio of the width of the brush to the width of commutator segments is

83. Which of the following motors is generally used in toys?

84. To reverse the direction of rotation of a capacitor-start motor while it is running we should

85. In a hysteresis motor, the rotor

86. Which motor has an unsymmetrical rotor?

87. The rotor of which motor does not have winding on it?

88. Which of the following applications always have switched on?

89. A capacitor-start single phase induction motor is switched on to supply with its capacitor replaced by an inductor of equivalent reactance value. It will

90. In a shaded-pole single-phase motor, the revolving field is produced by the use of

91. Which statement about resistance start split-phase motor is incorrect?

92. A repulsion motor is equipped with

93. The speed of a universal motor is usually reduced by using

94. Which of the following motor will give relatively high starting torque?

95. For the same rating which of the following motors has the highest starting torque ?

96. For a system involving sound recording and reproduction which motor would you select ?

97. In split-phase motor auxiliary winding is of

98. The rotor slots, in an induction motor, are usually not quite parallel to the shaft because it

99. In repulsion motor direction of rotation of motor

100. Burning out of windings is due to

101. A motor gets overheated due to

102. In a shaded-pole motor, a rotating magnetic field is produced by using

103. Which of the following motors is preferred for tape recorders?

104. The motor used on small lathes is usually

105. Which of the following motors-is used in a situation where load increases with speed ?

106. In a capacitor start and run motor the function of the running capacitor in series with the auxiliary winding is to

107. Which of the following motors is inherently self-starting?

108. Which of the following statements regarding the single-phase induction motor is correct?

109. In a universal motor, the most common cause of brush sparking is

110. When a ceiling fan employing a capacitor run motor is switched on, it hums but does not burn. When it is driven by external means, it runs in whatever direction it is made to run. The trouble is due to

111. Which of the following statements about the universal motor is incorrect?

112. In capacitor start single-phase motors

113. Hysteresis motor is particularly- useful for high-quality record players and tape recorders because

114. Single-phase induction motor usually operates on

115. If the capacitor of a single-phase motor is short-circuited

116. Which of the following motor will give the highest starting torque?

117. The direction of rotation of the universal motor can be reversed by reversing the flow of current through

118. Which of the following statements regarding the repulsion induction motor is incorrect?

119. Which of the following motors is used in mixies?

120. Which of the following Motors can be used for unity power factor?

121. In a two-value capacitor motor, the capacitor used for running purposes is

122. Which of the following motors will operate at high power factor?

123. The locked rotor current of a shaded pole motor is

124. If a single-phase induction motor runs slower than normal, the most likely defect is

125. The repulsion-start induction-run motor is used because of

126. Which of the following single-phase motors will be cheapest?

127. The power factor of a single-phase induction motor is usually

128. The shaded pole motor is used for

129. After the starting winding of a single-phase induction motor is disconnected from the supply, it continues to run only on

130. Which of the following single-phase motors has relatively poor starting torque ?

131. Which of the following single-phase motors is suitable for timing and control purposes?

132. The running winding of a single-phase motor on testing with megger is found to be ground. The most probable location of the ground will be

133. The speed/load characteristics of a universal motor is same as that of

134. In a repulsion motor, brushes are connected

135. Which of the following statements regarding two value capacitor motor is incorrect?

136. In a single-phase motor the centrifugal switch

137. A universal motor can run on

138. Which of the following motors can be run on A.C. as well as D.C. supply?

139. In a capacitor start motor, the phase displacement between starting and running winding can be nearly

140. Which type of load is offered by cranes and hoists?

141. Which of the following statements regarding hysteresis motor is incorrect?

142. In repulsion motor, zero torque is developed when

143. Torque developed by a single-phase induction motor at starting is

144. Which of the following motors is used in tape recorders?

145. The rotor developed by a single-phase motor at starting is

146. Which of the following is the most economical method of starting a single-phase induction motor?