# Quiz On Single Phase Motor, Electrical Machine Quiz

Hello Guys, welcome back to my blog. In this article, I will discuss quiz on single-phase motor, quiz questions related to the single-phase motor. Electrical machines MCQ with answers.

If you want an article on some other topics then comment us below in the comment section. You can also catch me @ Instagram – Chetan Shidling.

Quiz On Single Phase Motor

01. The efficiency rage of the shaded pole motors is

• (a) 95% to 99%
• (b) 80% to 90%
• (c) 50% to 75%
• (d) 5% to 35%

Ans: d

02. If the capacitor is replaced by resistance in capacitor start induction motor?

• (a) torque will increase
• (b) the power is less consumed by the motor
• (c) In the reverse direction, the motor will run
• (d) In the same direction, the motor will continue to run

Ans: d

03. The single-phase induction motor power factor is usually

• (a) lagging
• (c) unity
• (d) unity to 0.8 leading

Ans: a

04. The application of shaded pole motos is in?

• (a) toys
• (b) hair dryers
• (c) circulators
• (d) any of the above

Ans: d

05. The working principle of a hysteresis motor is

• (a) hysteresis loss
• (b) magnetization of rotor
• (c) eddy current loss
• (d) electromagnetic induction

Ans: a

06. The motor gives the highest starting torque in the following motors?

• (a) D.C. shunt motor
• (b) Schrage motor
• (c) Repulsion start and induction run the motor
• (d) Universal motor

Ans: b

07. The reluctance motor is preferred for which application?

• (a) Electric shavers
• (b) Refrigerators
• (c) Signaling and timing devices
• (d) Lifts and hoists

Ans: c

08. In the small lathes, the motor used is usually

• (a) universal motor
• (b) D.C. shunt motor
• (c) single-phase capacitor run motor
• (d) 3-phase synchronous motor

Ans: c

09. In the tape-recorders which of the following motor is used?

• (b) Hysteresis motor
• (c) Two value capacitor motor
• (d) Universal motor

Ans: b

10. A single-phase induction motor is inherently

• (a)  self-starting with high torque
• (b)  self-starting with low torque
• (c)  non-self-starting with low torque
• (d)  non-self-starting with high torque

Ans: c

11. A Schrage motor can run at

• (a) zero slip
• (b) negative slip
• (c) positive slip
• (d) all of the above

Ans: d

12. A universal motor can run at

• (a) A.C. only
• (6) D.C. only
• (c) either A.C. or D.C.
• (d) none of the above

Ans: c

13. For timing and control purposes, which of the following motor is suitable?

• (a) Reluctance motor
• (b) Series motor
• (c) Repulsion motor
• (d) Universal motor

Ans: a

14. The single-phase induction motor operates at

• (a) 0.6 power factor lagging
• (b) 0.8 power factor lagging
• (c) 0.8 power factor leading
• (d) unity power factor

Ans: a

15. The auxiliary winding in the split-phase motor is of

• (a) At the bottom thick wire is placed of the slots
• (b) At the top thick wire is placed of the slots
• (c) At the top thin wire is placed of the slots
• (d) At the bottom thin wire is placed of the slots

Ans: c

16. At the high power factor, which of the following motor operate?

• (a) Shaped pole motor
• (b) Split phase motor
• (c) Capacitor start motor
• (d) Capacitor run motor

Ans: d

17. The capacitor used for running purposes in a two-value capacitor motor is

• (a) air capacitor
• (b) paper spaced oil-filled type
• (c) ceramic type
• (d) a.c. electrolytic type

Ans: b

18. The motor which can run on AC. as well as D.C. supply?

• (a) Universal motor
• (b) Repulsion motor
• (c) Synchronous motor
• (d) Reluctance motor

Ans: a

19. The compensating winding used in A.C motor 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

Ans: c

20. In time phonographs, which of the following motor is used?

• (a) Resistance start
• (b) Capacitor start capacitor run
• (d) Universal

Ans: c

21. The following motor which has the highest starting torque?

• (a) Repulsion motor
• (b) Shaped pole motor
• (c) Capacitor-start motor
• (d) Split-phase motor

Ans: c

22. The repulsion-start induction-run motor is usually employed because of

• (a) good power factor
• (b) high efficiency
• (c) minimum cost
• (d) high starting torque

Ans: d

23. The direction of rotation of the motor in case of shaded pole motor is

• (a) from the main pole to shaded pole
• (b) from shaded pole to the main pole
• (c) either of the above depending on the voltage
• (d) On the power factor either of the depends

Ans: a

24. Which of the following needs more attention in the case of the high-speed universal motor?

• (a) End play
• (b) Air gap
• (c) Insulation in rotor
• (d) Balancing of rotor

Ans: d

25. The ceiling fan motor wattage rating is in the range of?

• (a) 200 to 250 W
• (b) 250 to 500 W
• (c) 50 to 150 W
• (d) 10 to 20 W

Ans: c

26. The running winding in the split-phase motor should have?

• (a) high resistance and low inductance
• (b) low resistance and high inductance
• (c) high resistance as well as high inductance
• (d) low resistance as well as low inductance

Ans: b

27. In the single-phase motor, if the capacitor is short-circuited?

• (a) the motor will not start
• (b) the motor will run
• (c) In the reverse direction, the motor will run
• (d) In the same direction, the motor will run at reduced r.p.m

Ans: a

28. In capacitor start single-phase motors

• (a) the current in the starting winding leads the applied voltage
• (b) the current in the starting winding lags the applied voltage
• (c) the current in the starting winding is in phase with the voltage in running winding
• (d) none of the above

Ans: a

29. The function of the running capacitor in series with the auxiliary winding in a capacitor start and run motors?

• (a) improve power factor
• (c) reduce fluctuations in torque
• (d) to improve torque

Ans: a

30. The phase displacement between running and the starting winding of the capacitor start motor is near?

• (a) 10°
• (b) 30°
• (c) 60°
• (d) 90°

Ans: d

31. In a split-phase motor?

• (a) the centrifugal switch is connected through the starting winding
• (b) the centrifugal switch is connected through the starting winding
• (c) the centrifugal switch is connected through both the starting and running winding
• (d) to control supply voltage the centrifugal switch is connected

Ans: a

32. In single-phase motor, the rotor developed at the starting is?

• (a) more than the rated torque
• (b) rated torque
• (c) less than the rated torque
• (d) zero

Ans: d

33. The motor which has high starting torque?

• (a) Capacitor start motor
• (b) Capacitor run motor
• (c) Split phase motor

Ans: a

34. The motor has a higher power factor?

• (a) Capacitor run motor
• (c) Capacitor start motor
• (d) Split phase motor

Ans: a

35. The revolving field is produced in the single-phase induction motor by the use of?

• (a) inductor
• (b) capacitor
• (c) resistor

Ans: d

36. A centrifugal switch is disconnected with the starting winding when the motor?

• (a) run for about 1 minute
• (b) run for about 5 minutes
• (c) comes to 50 to 70 percent of rated speed
• (d) comes to 10 to 25 percent of rated speed

Ans: c

37. which of the following motor will be preferred for high starting torque and high speed?

• (a) Universal motor
• (b) Shaded pole type motor
• (c) Capacitor start motor
• (d) Capacitor start and run motor

Ans: a

38. In the fractional horsepower motor, the starting capacitor value will be?

• (a) 100 uF
• (6) 200 uF
• (c) 300 uF
• (d) 400 uF

Ans: c

39. The direction of rotation of the motor in repulsion motor?

• (a) is opposite to that of brush shift
• (b) As brush shift is it is same
• (c) is independent of brush shift

Ans: b

40. In a single-phase motor the centrifugal switch

• (a) isolates auxiliary winding of the motor
• (b) isolates the main winding of the motor
• (c) the main winding of the motor is reconnected
• (d) the auxiliary winding of the motor is reconnected

Ans: a

41. In the capacitor-start single phase induction motor, if the capacitor replaced by an inductor of equivalent reactance value. It will?

• (a) start and then stop
• (b) start and run slowly
• (c) start and run at rated speed
• (d) not start at all

Ans: d

42. The motor used in the mixer?

• (a) Repulsion motor
• (b) Reluctance motor
• (c) Hysteresis motor
• (d) Universal motor

Ans: d

43. The motor which is self-starting?

• (a) Split motor
• (c) Reluctance motor
• (d) None of these

Ans: b

44. Burning out of windings in the motor is due to?

• (a) short-circuited capacitor
• (b) capacitor value hiving changed
• (c) open circuiting of the capacitor
• (d) none of the above

Ans: a