Single Phase Motor MCQ

21. Single-phase motor is made self-starting by the addition of a/an

1. running winding
2. starting winding
3. electric starter
4. autotransformer

22. As per double field revolving theory with slip denoted by s

1. The forward flux has a slip of s and backward flux have a slip of 2-s.
2. The forward flux has a slip of 2-s and backward flux have a slip of s.
3. The forward flux has a slip of 2+s and backward flux have a slip of 2-s.
   
4. The forward flux and backward flux have a slip of s.
   

23. A capacitor motor has a difficulty of starting. What is the probable cause?

1. Reversed magnetic field
2. Shorted commutator segments
3. Shorted windings
4. All options are correct

24. Which type of single-phase motor is relatively free from mechanical and magnetic vibrations?

1. Universal motor
2. Hysteresis motor
3. Shaded pole motor
4. Reluctance motor

25. By low voltage application, we can start a

1. Schrage motor
2. Synchronous motor
3. Slip ring induction motor
4. DC compound motor

26. Voltage limit for AC single phase induction motor is

1. 3 kV
2. 1.5 kV
3. 250 V
4. 11 kV

27. Speed control of Single phase series motor (AC) can be done by

1. Pole changing
2. Frequency variation
3. Voltage variation
4. Shifting of brushes

28. Single phase induction motor is also known as

1. multi horse power motor
2. single horse power motor
3. fraction horse power motor
4. double horse power motor

29. Punching machine is characterized as

1. continuous full load
2. no load
3. continuous part load
4. impact load

30. In FHP induction motors, splitting the phase is done using:

1. Only capacitor
2. Only resistance
3. Resistance/capacitor
4. Resistance/inductance