[amp_mcq option1=”maintaining constant excitation” option2=”running the motor on leading power factors” option3=”providing damper bars in the rotor pole faces” option4=”oscillations cannot be damped” correct=”option3″]
The correct answer is: C. providing damper bars in the rotor pole faces.
Dampers bars are a type of winding that is placed in the rotor of a synchronous motor. They help to reduce the oscillations of the motor by providing a path for current to flow when the motor is not synchronized with the power grid. This current helps to stabilize the motor and prevent it from oscillating.
Option A is incorrect because maintaining constant excitation will not help to damp out the oscillations of the motor. In fact, it may actually make the oscillations worse.
Option B is incorrect because running the motor on leading power factors will not help to damp out the oscillations of the motor. In fact, it may actually make the oscillations worse.
Option D is incorrect because oscillations can be damped out by providing damper bars in the rotor pole faces.