MCQ on Single Phase Induction Motor

1. In a split phase motor, the running winding 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

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

(a) the motor will not start
(b) the motor will run
(c) the motor will run in reverse direction
(d) the motor will run in the same direction at reduced R.P.M.

3. In capacitor start single-phase motors

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

4. In a split phase motor

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

5. The torque developed by a single phase motor at starting is

(a) more than the rated torque
(b) rated torque
(c) less than the rated torque

6. Burning out of windings is due to

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

7. Short-circuiter is used in

(a) repulsion induction motor
(b) repulsion motor
(c) repulsion start induction run motor
(d) none of the above

8. The range of efficiency for shaded pole motors is

(a) 95% to 99%
(b) 30% to 90%
(c) 50% to 75%
(d) 5% to 35%

9. In a capacitor start single-phase motor when capacitor Is replaced by a resistance

(a) torque will increase
(c) the motor will consume less power
(c) motor will run in reverse direction
(d) motor will continue to run in same direction

10. A hysteresis motor works on the principle of

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

11. 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

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

(a) gear trains
(b) V-belts
(c) brakes
(d) chains

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

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

14. 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

15. Which of the following motors is preferred for sound recording systems ?

(a) Shaded pole motor
(b) Hysteresis motor
(c) Two value capacitor motor
(d) Universal motor

16. A Shrage motor can run on

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

17. 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

18. 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

19. 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

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

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

21. 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) electrolytic type

22. 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

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

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

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

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

25.In case of 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

26. 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

27. 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

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

(a) Universal motor
(b) Repulsion motor
(c) Capacitor motor
(d) All single phase motors have zero starting torque

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

(a) Gradually varying load
(b) Non-reversing, no-load start
(c) Reversing, light start
(d) Reversing, heavy start

 

1. MCQ on Single Phase Induction Motor
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4. Single Phase Induction Motor MCQ

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