Synchronous Motors The pull out torque of a practical synchronous motor will occur when the torque angle is about _____ 45° 75° 30° 0° 45° 75° 30° 0° ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors The speed of a synchronous motor can be changed by varying _______ Supply frequency None of the listed here Mechanical load Field excitation Supply frequency None of the listed here Mechanical load Field excitation ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors A synchronous motor connected to infinite bus-bars has at constant full load, 100% excitation and unity power factor. On changing the excitation only, the armature current will have no change of power factor leading power factor with under-excitation leading power factor with over-excitation lagging power factor with over-excitation no change of power factor leading power factor with under-excitation leading power factor with over-excitation lagging power factor with over-excitation ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors When pull-out torque occurs in a synchronous motor, the poles of the rotor are _______ Mid way between N and S poles of stator 45° (electrical) behind stator poles Coincident with statorbpoles None of the listed here Mid way between N and S poles of stator 45° (electrical) behind stator poles Coincident with statorbpoles None of the listed here ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors In case one phase of a three-phase synchronous motor is short-circuited the motor will take less than the rated load not start run with excessive vibrations run at 2/3 of synchronous speed take less than the rated load not start run with excessive vibrations run at 2/3 of synchronous speed ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors By which of the following methods the constant speed of a synchronous motor can be changed to new fixed value ? By changing the applied voltage By changing the supply frequency By changing the load By interchanging any two phases By changing the applied voltage By changing the supply frequency By changing the load By interchanging any two phases ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS