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 leading power factor with over-excitation leading power factor with under-excitation lagging power factor with over-excitation no change of power factor leading power factor with over-excitation leading power factor with under-excitation lagging power factor with over-excitation no change of power factor ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors If the synchronous motor, properly synchronised to the supply is running on no load and is having negligible loss then the back e.m.f. will be more than the supply voltage the stator current will be zero the stator current will be very small the stator current will be very high the back e.m.f. will be more than the supply voltage the stator current will be zero the stator current will be very small the stator current will be very high ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors Damper winding in a synchronous motor________ Serves to start the motor Reduces windage losses Improve pf of the motor Increases hunting of the motor Serves to start the motor Reduces windage losses Improve pf of the motor Increases hunting of the motor ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors An under excited synchronous motor behaves as_______ An inductor A resistor A capacitor None of the listed here An inductor A resistor A capacitor None of the listed here ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors The power factor of a synchronous motor is better than that of induction motor because stator supply is relieved of responsibility of producing magnetic field synchronous motor runs at synchronous speed synchronous motor has large air gap mechanical load on the motor can be adjusted stator supply is relieved of responsibility of producing magnetic field synchronous motor runs at synchronous speed synchronous motor has large air gap mechanical load on the motor can be adjusted ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors The speed of a synchronous motor can be changed by varying _______ Field excitation Supply frequency Mechanical load None of the listed here Field excitation Supply frequency Mechanical load None of the listed here ANSWER DOWNLOAD EXAMIANS APP
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