MCQ on Single Phase Motor 19-48

19. A capacitor start single phase induction motor will usually have a power factor of
(A) unity
(B) 0.8 leading
(C) 0.6 leading
(D) 0.6 lagging.✔

20. A capacitor start, capacitor run single phase induction motor is basically a
(A) ac series motor
(B) dc series motor
(C) 2 phase induction motor✔
(D) 3 phase induction motor.

21. The starting torque of a capacitor start motor is
(A) zero
(B) low✔
(C) same as rated torque
(D) more than rated torque.

22. The torque developed by a split phase motor is proportional to
(A) Sine of angle between lm and ls✔
(B) Cosine of angle between lm and Is
(C) Main winding current, Im
(D) Auxiliary winding current,Is

23. A capacitor start single phase induction motor is switched on the supply with its capacitor replaced by an inductor of equivalent reactance value. It will
(A) not start✔
(B) start and run
(C) start and then stall
(D) none of the above.

24. The starting capacitor of a single phase motor is
(A) Electrolytic capacitor✔
(B) Ceramic capacitor
(C) Paper capacitor
(D) None of the above.

25. Which of the following is the most economical method of starting a single phase motor ?
(A) Resistance start method
(B) Inductance start method
(C) Capacitance start method✔
(D) Split-phase method.

26. The number of turns in the starting winding of a capacitor start motor as compared to that for split phase motor is
(A) same
(B) more✔
(C) less
(D) none of the above.

27. In a split phase motor, the ratio of number of turns for starting winding to that for running winding is
(A) 2.0
(B) more than 1
(C) 1.0
(D) less than 1.✔

28. A single phase motor generally used for small air compressor is
(A) capacitor start capacitor run motor✔
(B) reluctance motor
(C) universal motor
(D) shaded pole motor.

29. Out of the following motors, which will give the highest starting torque ?
(A) Universal motor
(B) Capacitor start motor✔
(C) Shaded pole motor
(D) All have zero starting torque.

30. Which single phase ac motor will you select for record players and tape recorders ?
(A) Hysteresis motor✔
(B) Shaded pole motor
(C) Reluctance motor
(D) Two value capacitor motor.

31. A universal motor is one
(A) which can run on any value of supply voltage
(B) which has infinitely varying speed
(C) which can operate on ac as well as dc voltage✔
(D) which can work as single phase or three phase motor.

32. Under normal operating conditions which motor can run at 5000 rpm ?
(A) Synchronous motor
(B) Induction motor
(C) Universal motor✔
(D) No motor can give 5000 rpm.

33.The motor used in household refrigerator is
(A) dc series motor
(B) dc shunt motor
(C) universal motor
(D) single phase induction motor.✔

34. The direction of rotation of universal motor can be reversed by
(A) reversing the supply terminals
(B) switching over from ac to dc
(C) interchanging the brush leads✔
(D) any of the above.

35. A universal motor operates on
(A) constant speed and varying load
(B) constant load and varying speed
(C) approximately constant speed and load✔
(D) synchronous speed with varying load.

36. Which of the following single phase motors will operate at high power factor ?
(A) shaded pole motor
(B) capacitor run motor✔
(C) split phase motor
(D) capacitor start motor.

37. A motor suitable for signaling device is
(A) induction motor
(B) dc shunt motor
(C) dc series motor
(D) reluctance motors.✔

38. Which capacitor is preferred in case of single phase motor
(A) Paper capacitor
(B) Ceramic capacitor
(C) Mica capacitor
(D) Electrolytic capacitor.✔

39. The motor used for driving the record player deck is
(A) dc series motor
(B) synchronous motor
(C) hysteresis motor✔
(D) dc shunt motor.

40. When a motor speed of 5000 rpm is required, which motor will you select ?
(A) Capacitor start motor
(B) Shaded pole motor
(C) Hysteresis motor
(D) Universal motor✔

41. As compared to other single phase ac motors a universal motor has
(A) speed ratio of 2: 1 on ac/dc
(B) highest efficiency on 50 Hz supply
(C) high horse power/kg ratio✔
(D) all of the above.

42. When a universal motor is operated on no load, its speed is limited by
(A) armature reaction
(B) armature weight
(C) windage and friction✔
(D) supply voltage frequency.

43. Which of the following applications make use of a universal motor ?
(A) Floor polishing machine
(B) Oil expeller
(C) Portable tools✔
(D) Lathe machines.

44. In portable tools the speed of the driven shaft is reduced by
(A) Gearing✔
(B) Belt drive
(C) Chain drive
(D) Fluid drive

45. For ceiling fans generally the single phase motor used is
(A) split phase type
(B) capacitor start type
(C) capacitor start and run type
(D) permanent capacitor type.✔

46. In case of split phase motors the phase shift is usually limited to
(A) 3 degrees✔
(B) 60 degrees
(C) 90 degrees
(D) 150 degrees.

47. The capacitance of a small single phase motor will be of the order of
(A) Kilo farads
(B) Few hundred farads
(C) Farads
(D) Micro or pico farads.✔

48. the single Ф motor commercially Manufactured up to
(a) 1HP
(b) 2 HP✔
(c) 5 HP
(c) 10HP