MCQ on single phase motor 61 to 80

61. For which of the applications a reluctance motor is preferred ?
(a) Electric shavers
(b) Refrigerators
(c) Signalling and timing devices✔
(d) Lifts and hoists

62. The motor used on small lathes is usually
(a) universal motor
(b) D.C. shunt motor
(c) single-phase capacitor run motor✔
(d) 3-phase synchronous motor

63. Which of the following motors is preferred for tape-recorders ?
(a) Shaded pole motor
(b) Hysteresis motor✔
(c) Two value capacitor motor
(d) Universal motor

64. A single-phase induction motor is
(a) inherently self-starting with high torque
(b) inherently self-starting with low torque
(c) inherently non-self-starting with low torque✔
(d) inherently non-self-starting with high torque

65. A schrage motor can run on
(a) zero slip
(b) negative slip
(c) positive slip
(d) all of the above✔

66. A universal motor can run on
(a) A.C. only
(6) D.C. only
(c) either A.C. or D.C.✔
(d) none of the above

67. Which of the following single-phase motors is suitable for timing and control purposes ?
(a) Reluctance motor✔
(b) Series motor
(c) Repulsion motor
(d) Universal motor

68. Single phase induction motor usually operates on
(a) 0.6 power factor lagging✔
(b) 0.8 power factor lagging
(c) 0.8 power factor leading
(d) unity power factor

69. In split-phase motor auxiliary winding is of
(a) thick wire placed at the bottom of the slots
(b) thick wire placed at the top of the slots
(c) thin wire placed at the top of the slots✔
(d) thin wire placed at the bottom of the slots

70. Which of the following motors will operate at high power factor ?
(a) Shaped pole motor
(b) Split phase motor
(c) Capacitor start motor
(d) Capacitor run motor✔

71. In a two value capacitor motor, the capacitor used for running purposes is
(a) air capacitor
(b) paper spaced oil filled type✔
(c) ceramic type
(d) a.c. electrolytic type

72. Which of the following motors can be run on AC. as well as D.C. supply ?
(a) Universal motor✔
(b) Repulsion motor
(c) Synchronous motor
(d) Reluctance motor

73. In A.C. series motor compensating winding is employed to
(a) reduce the effects of armature reaction
(b) increase the torque
(c) reduce sparking at the brushes✔
(d) none of the above

74. Which of the following single-phase induction motors is generally used in time phonographs ?
(a) Resistance start
(b) Capacitor start capacitor run
(c) Shaded pole✔
(d) Universal

75. Which of the following motors has highest starting torque ?
(a) Repulsion motor
(b) Shaped pole motor
(c) Capacitor-start motor✔
(d) Split-phase motor

76. The repulsion-start induction-run motor is used because of
(a) good power factor
(b) high efficiency
(c) minimum cost
(d) high starting torque✔

77. In case of a shaded pole motor the direction of rotation of the motor is
(a) from main pole to shaded pole✔
(b) from shaded pole to main pole
(c) either of the above depending on voltage
(d) either of the above depending on power factor

78. In case of high speed universal motor which of the following needs more attention ?
(a) End play
(b) Air gap
(c) Insulation in rotor
(d) Balancing of rotor✔

79. The wattage rating for a ceiling fan motor will be in the range
(a) 200 to 250 W
(b) 250 to 500 W
(c) 50 to 150 W✔
(d) 10 to 20 W

80. The wattage of motor for driving domestic sewing machine will be around
(a) 100 to 150 W✔
(b) 40 to 75 W
(c) 10 to 30 W
(d) 5 to 10 W