Synchronous Motors In a synchronous motor, the magnitude of stator back emf depends on _____ Load on the motor Both the speed and rotor flux Speed of the rotor Dc excitation only Load on the motor Both the speed and rotor flux Speed of the rotor Dc excitation only ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors The armature current of a synchronous motor will be minimum for ______ power factor. 0.8 lagging None of the listed here Unity 0.8 leading 0.8 lagging None of the listed here Unity 0.8 leading 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 pull out torque of a synchronous motor is generally ______ times its full-load torque. 1.25 to 3.5 0.5 5 to 10 6 to 9 1.25 to 3.5 0.5 5 to 10 6 to 9 ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors The pull out torque of a practical synchronous motor will occur when the torque angle is about _____ 30° 75° 0° 45° 30° 75° 0° 45° ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors If a synchronous motor is operating at a supply frequency of 50 cycles/second, then, rotor revolves at ______ 100 cycles/second 25 cycles/ second None of the listed here 50 cycles/second 100 cycles/second 25 cycles/ second None of the listed here 50 cycles/second ANSWER DOWNLOAD EXAMIANS APP