Objective Questions on Single Phase Motors

16. Single phase motors are commercially manufactured up to

A 1 H.P.
B 2 H.P.
C 5 H.P.
D 10 H.P.

17. 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.

18. 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.

19. 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.

20. A motor suitable for signaling device is

A induction motor
B dc shunt motor
C dc series motor
D reluctance motors.

21. Which capacitor is preferred in case of single phase motor

A Paper capacitor
B Ceramic capacitor
C Mica capacitor
D Electrolytic capacitor.

22. The motor used for driving the record player deck is

A dc series motor
B synchronous motor
C hysteresis motor
D dc shunt motor.

23. 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.

24. 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.

25. 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.

26. Which of the following applications make use of a universal motor ?

A Floor polishing machine
B Oil expeller
C Portable tools
D Lathe machines.

27. In portable tools the speed of the driven shaft is reduced by

A Gearing
B Belt drive
C Chain drive
D Fluid coupling.

28. 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.

29. 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.