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EEE :: Single Phase Induction Motors

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

  2. A.

     Shaped pole motor

    B.

     Split phase motor

    C.

     Capacitor start motor

    D.

     Capacitor run motor


  3. Single phase induction motor usually operates on

  4. A.

     0.6 power factor lagging

    B.

     0.8 power factor lagging

    C.

     0.8 power factor leading

    D.

     unity power factor


  5. In a split phase motor, the running winding should have

  6. 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 inductiance


  7. If the centrifugal switch does not open at 70 to 80 percent of synchronous speed of motor, it would result in

  8. A.

     Damage to the starting winding

    B.

     Damage to the centrifugal switch

    C.

     Overloading of running winding

    D.

     None of the above


  9. A.C. series motor as compared to D.C. series motor has

  10. 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


  11. If a D.C. series motor is operated on A.C. supply, it will

  12. A.

     spark excessively

    B.

     have poor efficiency

    C.

     have poor power factor

    D.

     all of the above


  13. In a capacitor start single-phase motor, when capacitor is replaced by a resistance

  14. A.

     torque will increase

    B.

     the motor will consume less power

    C.

     motor will run in reverse direction

    D.

     motor will continue to run in same direction


  15. A schrage motor can run on

  16. A.

     zero slip

    B.

     negative slip

    C.

     positive slip

    D.

     all of the above


  17. Which motor is normally free from mechanical and magnetic vibrations ?

  18. A.

     Split phase motor

    B.

     Universal motor

    C.

     Hysteresis motor

    D.

     Shaded pole motor


  19. Speed torque characteristic of a repulsion induction motor is similar to that of a D.C.

  20. A.

     shunt motor

    B.

     series motor

    C.

     compound motor

    D.

     separately excited motor