When the stator windings are connected in such a fashion that the number of poles are made half, the speed of the rotor of a synchronous motor___________?

Related Mcqs:

1. When the rotor speed, in a synchronous machine, becomes more than the synchronous speed during hunting, the damper bars develop_________________?

   A. inductor motor torque
   B. induction generator torque
   C. synchronous motor torque
   D. d.c. motor toque
   E. none of the above

2. The angle between the rotating stator flux and rotor poles is called _________ angle.

   A. synchronizing
   B. obtuse
   C. torque
   D. power factor

3. The mechanical displacement of the rotor with respect to the stator, in polyphase multipolar synchronous motors running at full load, is of the order of_____________?

   A. zero degree
   B. two degrees
   C. five degrees
   D. ten degrees

4. The maximum torque which a synchronous motor will develop at rest for any angular position of the rotor, at rated stator supply voltage and frequency, is known as__________?

   A. locked-rotor torque
   B. synchronous torque
   C. pull up torque
   D. reluctance torque

5. In which of the following motors the stator and rotor magnetic field rotate at the same speed?

   A. Universal motor
   B. Synchronous motor
   C. Induction motor
   D. Reluctance motor

6. A synchronous motor installed at the receiving end substation operates with such an excitation that it takes power at lagging power factor. Now if the applied voltage of the synchronous motor goes down, the power factor of the synchronous motor will___________?

   A. remain same
   B. go down
   C. improve
   D. none of the above

7. In which of the following motors the stator and rotor fields rotate simultaneously?

   A. D.C. motor
   B. Reluctance motor
   C. Universal motor
   D. Synchronous motor
   E. Induction motor

8. In a synchronous motor, damper windings are provided on____________?

   A. stator frame
   B. rotor shaft
   C. pole faces
   D. none of the above

9. In a synchronous motor, the magnitude of stator back e.m.f. Eb depends on___________?

   A. load on the motor
   B. d.c. excitation only
   C. both the speed and rotor flux
   D. none of the above

10. In a synchronous motor, the magnitude of stator back e.m.f. & depends on_______________?

    A. d.c. excitation only
    B. speed of the motor
    C. load on the motor
    D. both the speed and rotor flux