Synchronous Motors Synchronous motors are generally used in application requiring _______ Sudden application of heavy loads Variable speed Frequent stopping Infrequent starting Sudden application of heavy loads Variable speed Frequent stopping Infrequent starting ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors In a synchronous motor it the back e.m.f. generated in the armature at noload is approximately equal to the applied voltage, then the excitation is said to be zero per cent the torque generated is maximum the motor is said to be fully loaded the excitation is said to be hundred per cent the excitation is said to be zero per cent the torque generated is maximum the motor is said to be fully loaded the excitation is said to be hundred per cent ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors A synchronous machine with low value of short-circuit ratio has lower stability limit high stability limit good voltage regulation good speed regulation lower stability limit high stability limit good voltage regulation good speed regulation 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 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 ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors As the load is applied to a synchronous motor, the motor takes more armature current because The back e.m.f. decreases causing an increase in motor current The rotor strengthens the rotating field causing more motor current The rotor by shifting its phase backward causes motor to take more current The increased load has to take more current The back e.m.f. decreases causing an increase in motor current The rotor strengthens the rotating field causing more motor current The rotor by shifting its phase backward causes motor to take more current The increased load has to take more current ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors A three phase synchronous motor will have Two slip rings No slip rings Three slip rings One slip rings Two slip rings No slip rings Three slip rings One slip rings ANSWER DOWNLOAD EXAMIANS APP
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