Synchronous Motors A synchronous machine with low value of short-circuit ratio has high stability limit lower stability limit good speed regulation good voltage regulation high stability limit lower stability limit good speed regulation good voltage regulation ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors Damper winding in a synchronous motor________ Improve pf of the motor Reduces windage losses Increases hunting of the motor Serves to start the motor Improve pf of the motor Reduces windage losses Increases hunting of the motor Serves to start the motor 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 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 The duration of sudden short circuit test on synchronous motor is usually about One second One hour None of the listed here One minute One second One hour None of the listed here One minute ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors When pull-out torque occurs in a synchronous motor, the poles of the rotor are _______ Coincident with statorbpoles None of the listed here 45° (electrical) behind stator poles Mid way between N and S poles of stator Coincident with statorbpoles None of the listed here 45° (electrical) behind stator poles Mid way between N and S poles of stator ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors When the field of a synchronous motor is under-excited, the power factor will be lagging zero leading unity lagging zero leading unity ANSWER DOWNLOAD EXAMIANS APP
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