A hysteresis motor works on the principle of__________?

Related Mcqs:

1. The direction of rotation of an hysteresis motor is determined by____________?

   A. interchanging the supply leads
   B. position of shaded pole with respect to main pole
   C. retentivity of the rotor material
   D. none of these

2. Which of the following statements regarding hysteresis motor is in incorrect?

   A. It is extremely sensitive to fluctuations in supply voltage
   B. Its high starting torque is due to its high rotor hysteresis loss
   C. It is extremely quiet in operation
   D. It accelerates from rest to full-speed almost instantaneously

3. Hysteresis motor is particularly useful for high-quality record players and tape-recorders because___________?

   A. it revolves synchronously
   B. it is not subject to any magnetic or mechanical vibrations
   C. it can be easily manufactured in extremely small sizes of up to 1 W output
   D. it develops hysteresis torque which is extremely steady both in amplitude and phase

4. In a hysteresis motor, the rotor must have____________?

   A. retentivity
   B. resistivity
   C. susceptibility
   D. none of the above

5. The rotor of a hysteresis motor is made of___________?

   A. aluminium
   B. cast iron
   C. chrome steel
   D. copper

6. As hysteresis motors are free from mechanical and magnetic vibrations therefore these are considered as suitable for__________?

   A. fans
   B. blowers
   C. sound equipment
   D. mixer grinders

7. Direction of rotation of a split phase motor can be reversed by reversing the connection of__________?

   A. running winding only
   B. starting winding only
   C. either A. or (b)
   D. both A. and (b)

8. 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

9. 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

10. 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