Most Synchronous Motors

121. While starting a salient pole synchronous motor by induction motor action and connecting field discharge resistance across field, starting and accelerting torque is produced by

1. induction motor torque in field winding
2. induction motor torque in damper winding
3. eddy current and hysteresis torque in pole faces
4. reHetance motor torque due to saliency of the rotor
5. all of the above methods

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122. While starting a synchronous motor by induction motor action, field winding is usually

1. connected to D.C. supply
2. short-circuited by low resistance
3. kept open-circuited
4. none of the above

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