Synchronous Motors While running, a synchronous motor is compelled to run at synchronous speed because of _______ Damper winding in its pole faces Compulsion due to lenz's law Induced emf in rotor field winding by stator flux Magnetic locking between stator and rotor poles Damper winding in its pole faces Compulsion due to lenz's law Induced emf in rotor field winding by stator flux Magnetic locking between stator and rotor poles ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors Damper winding in a synchronous motor________ Serves to start the motor Reduces windage losses Increases hunting of the motor Improve pf of the motor Serves to start the motor Reduces windage losses Increases hunting of the motor Improve pf of the motor ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors When load on an over-excited or under excited synchronous motor is increased, rate of change of its armature current as compared with that of power factor is less more twice equal less more twice equal ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors If the synchronous motor, properly synchronised to the supply is running on no load and is having negligible loss then the stator current will be very high the stator current will be zero the stator current will be very small the back e.m.f. will be more than the supply voltage the stator current will be very high the stator current will be zero the stator current will be very small the back e.m.f. will be more than the supply voltage ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors The duration of sudden short-circuit test on a synchronous motor is usually about one second None of these one minute one hour one second None of these one minute one hour ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors If one phase of a 3 phase synchronous motor is short circuited, motor Will overheat in spots Will refused ro start Will fail to pull into step Will not come upto speed Will overheat in spots Will refused ro start Will fail to pull into step Will not come upto speed ANSWER DOWNLOAD EXAMIANS APP
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