In a synchronous motor, damper windings are provided on

The correct answer is: C. pole faces

Damper windings are provided on the pole faces of a synchronous motor to reduce hunting. Hunting is a self-excited oscillation that can occur in a synchronous motor when the load torque is not constant. The damper windings provide a damping torque that opposes the hunting motion and helps to stabilize the motor.

The stator frame is the stationary part of the motor that contains the stator windings. The rotor shaft is the rotating part of the motor that contains the rotor windings. The pole faces are the surfaces of the rotor that are located between the stator poles.

The following is a brief explanation of each option:

• A. stator frame The stator frame is the stationary part of the motor that contains the stator windings. The stator windings are responsible for creating the magnetic field that interacts with the rotor windings to produce torque. The stator frame is not directly involved in the hunting motion, so it does not make sense to provide damper windings on the stator frame.
• B. rotor shaft The rotor shaft is the rotating part of the motor that contains the rotor windings. The rotor windings are responsible for creating the magnetic field that interacts with the stator windings to produce torque. The rotor shaft is not directly involved in the hunting motion, so it does not make sense to provide damper windings on the rotor shaft.
• C. pole faces The pole faces are the surfaces of the rotor that are located between the stator poles. The pole faces are responsible for creating the magnetic field that interacts with the stator windings to produce torque. The pole faces are directly involved in the hunting motion, so it makes sense to provide damper windings on the pole faces.
• D. none of the above None of the other options are directly involved in the hunting motion, so it does not make sense to provide damper windings on any of them.