MCQ on single phase motor 49-60

49. Which of the following motors is used in mixies ?
(a) Repulsion motor
(b) Reluctance motor
(c) Hysteresis motor
(d) Universal motor✔

50. Which of the following motors is inherently self starting ?
(a) Split motor
(b) Shaded-pole motor✔
(c) Reluctance motor
(d) None of these

51. The direction of rotation of an hysteresis motor is determined by
(a) interchanging the supply leads
(b) position of shaded pole with respect to main pole✔
(c) retentivity of the rotor material
(d) none of these

52. Burning out of winding is due to
(a) short circuited capacitor✔
(b) capacitor value hiving changed
(c) open circuiting of capacitor
(d) none of the above

53. Direction of rotation of a split phase motor can be reversed by reversing the connection of
(a) running winding only
(b) starting winding only
(c) either (a) or (b)✔
(d) both (a) and (b)

54. Short-circuiter is used in
(a) repulsion induction motor
(b) repulsion motor
(c) repulsion start induction run motor✔
(d) none of the above

55. The range of efficiency for shaded pole motors is
(a) 95% to 99%
(b) 80% to 90%
(c) 50% to 75%
(d) 5% to 35%✔

56. In a capacitor start single-phase motor, when capacitor is replaced by a resistance
(a) torque will increase
(b) the motor will consume less power
(c) motor will run in reverse direction
(d) motor will continue to run in same direction✔

57. The power factor of a single-phase induction motor is usually
(a) lagging✔
(b) always leading
(c) unity
(d) unity to 0.8 leading

58. A shaded pole motor can be used for
(a) toys
(b) hair dryers
(c) circulators
(d) any of the above✔

59. A hysteresis motor works on the principle of
(a) hysteresis loss✔
(b) magnetisation of rotor
(c) eddy current loss
(d) electromagnetic induction

60. Which of the following motor will give the highest starting torque ?
(a) D.C. shunt motor
(b) Schrage motor✔
(c) Repulsion start and induction run motor
(d) Universal motor