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 over-excitation leading power factor with under-excitation no change of power factor lagging power factor with over-excitation leading power factor with over-excitation leading power factor with under-excitation no change of power factor ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors In a synchronous motor, the magnitude of stator back emf depends on _____ Speed of the rotor Load on the motor Dc excitation only Both the speed and rotor flux Speed of the rotor Load on the motor Dc excitation only Both the speed and rotor flux ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors Change of D.C. excitation of a synchronous motor changes Any of the above Motor speed Power factor of power drawn by the motor Applied voltage of the motor Any of the above Motor speed Power factor of power drawn by the motor Applied voltage of the motor ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors The maximum speed variation in a 3 phase synchronous motor is 4 percent 2 percent Zero 10 percent 4 percent 2 percent Zero 10 percent ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors If a synchronous motor is operating at a supply frequency of 50 cycles/second, then, rotor revolves at ______ 50 cycles/second 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 ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors A synchronous motor is cheaper than 3-phase induction motor for _____ Low speed, high output High speed, low output None of the listed here High speed, high output Low speed, high output High speed, low output None of the listed here High speed, high output ANSWER DOWNLOAD EXAMIANS APP
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