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.
30. 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.
