The correct answer is C. Damper winding in conjunction with star-delta starter.
A synchronous motor is a type of AC motor that runs at a constant speed, regardless of the load. It is used in a variety of applications, including fans, pumps, and compressors.
To start a synchronous motor, the rotor must be brought up to speed. This is done by using a starter to connect the motor to the power supply. The starter then gradually increases the voltage applied to the motor until it reaches its rated speed.
There are two main types of starters used to start synchronous motors: star-delta starters and damper winding starters.
A star-delta starter connects the motor to the power supply in a star configuration. This reduces the voltage applied to the motor, which makes it easier to start. Once the motor is up to speed, the starter switches the motor to a delta configuration. This increases the voltage applied to the motor and allows it to operate at its rated speed.
A damper winding starter uses a set of windings in the rotor to help the motor start. These windings are connected to a capacitor, which creates a magnetic field that helps to pull the rotor up to speed.
In some cases, a damper winding starter may be used in conjunction with a star-delta starter. This provides a smoother start for the motor and reduces the stress on the windings.
Resistance starter in the armature circuit is not a method used to start a synchronous motor.