In a A.C. series motor armature coils are usually connected to commutator____________?

Related Mcqs:

1. A.C. series motor as compared to D.C. series motor has__________?

   A. smaller brush width
   B. less number of field turns
   C. more number of armature turns
   D. less air gap
   E. all of the above

2. When a D.C. series motor is connected to A.C. supply, the power factor will be low because of____________?

   A. high inductance of field and armature circuits
   B. induced current in rotor due to variations of flux
   C. fine copper wire winding
   D. none of the above

3. 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

4. If a D.C. series motor is operated on A.C. supply, it will____________?

   A. spark excessively
   B. have poor efficiency
   C. have poor power factor
   D. all of the above

5. In case of a 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

6. Two-value capacitor motor finds increased application as compressor motor in small home air-conditioners because_____________?

   A. it is comparatively cheaper
   B. it has almost non-destructible capacitor
   C. it has low starting as well as running currents at relatively high power factor
   D. it is quiet in operation

7. In case of a reluctance motor, when the load is increased so that it cannot maintain synchronous speed the motor will_____________?

   A. become unstable
   B. draw excessive armature current and may burn out
   C. fall out of synchronism and come to stand still
   D. run as induction motor

8. In a shaded pole motor, the shading coil usually consist of___________?

   A. a single turn of heavy wire which is in parallel with running winding
   B. a single turn of heavy copper wire which is short-circuited and carries only induced current
   C. a multilayer fine gauge copper wire in parallel with running winding
   D. none of the above

9. The speed of a universal motor is usually reduced by using____________?

   A. gearing
   B. belts
   C. brakes
   D. chains

10. The rotor slots, in an induction motor, are usually not quite parallel to the shaft because it_____________?

    A. improves the efficiency
    B. helps the rotor teeth to remain under the stator teeth
    C. helps in reducing the tendency of the rotor teeth to remain under the stator teeth
    D. improves the power factor