Synchronous Motors For power factor correction, synchronous motors operate at normal load with zero excitation no-load and greatly over-excited fields no-load and under-excited fields normal load with minimum excitation normal load with zero excitation no-load and greatly over-excited fields no-load and under-excited fields normal load with minimum excitation ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors When a synchronous motor is on no load, the torque angle is about ________ 0° electrical 45° electrical 30° electrical 90° electrical 0° electrical 45° electrical 30° electrical 90° electrical ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors Change of D.C. excitation of a synchronous motor changes Applied voltage of the motor Power factor of power drawn by the motor Motor speed Any of the above Applied voltage of the motor Power factor of power drawn by the motor Motor speed Any of the above 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 lagging power factor with over-excitation leading power factor with under-excitation leading power factor with over-excitation no change of power factor lagging power factor with over-excitation leading power factor with under-excitation leading power factor with over-excitation no change of power factor ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors The net armature voltage of a synchronous motor is equal to the vector difference of Eh and V arithmetic difference of Eb and V vector sum of Eb and V arithmetic sum of Eb and V vector difference of Eh and V arithmetic difference of Eb and V vector sum of Eb and V arithmetic sum of Eb and V ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors Damper winding in a synchronous motor________ Reduces windage losses Increases hunting of the motor Improve pf of the motor Serves to start the motor Reduces windage losses Increases hunting of the motor Improve pf of the motor Serves to start the motor ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS