Synchronous Motors The back emf in the stator of a synchronous motor depends on Rotor excitation Rotor speed None of the listed here Flux density Rotor excitation Rotor speed None of the listed here Flux density ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors As the load is applied to a synchronous motor, the motor takes more armature current because The rotor by shifting its phase backward causes motor to take more current The back e.m.f. decreases causing an increase in motor current The increased load has to take more 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 back e.m.f. decreases causing an increase in motor current The increased load has to take more current The rotor strengthens the rotating field causing more motor current ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors The speed regulation of a synchronous motor is always 1% Positive Zero 0.5% 1% Positive Zero 0.5% ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors The pull out torque of a synchronous motor is generally ______ times its full-load torque. 6 to 9 1.25 to 3.5 0.5 5 to 10 6 to 9 1.25 to 3.5 0.5 5 to 10 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 leading power factor with under-excitation lagging power factor with over-excitation leading power factor with over-excitation no change of power factor leading power factor with under-excitation lagging power factor with over-excitation leading power factor with over-excitation no change of power factor ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors When the synchronous motor is pulled out of synchronism, the stator current _______ Is decreased too much Is increased too much Remains unchanged Becomes zero Is decreased too much Is increased too much Remains unchanged Becomes zero ANSWER DOWNLOAD EXAMIANS APP
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