Synchronous Motors A three phase synchronous motor will have One slip rings No slip rings Three slip rings Two slip rings One slip rings No slip rings Three slip rings Two slip rings 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 equal more less twice equal more less twice 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 back e.m.f. will be more than the supply voltage the stator current will be zero the stator current will be very high the stator current will be very small the back e.m.f. will be more than the supply voltage the stator current will be zero the stator current will be very high the stator current will be very small ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors The magnitude of field flux in a 3-phase synchronous motor Varies with power factor Varies with speed Varies with the load Remains constant at all loads Varies with power factor Varies with speed Varies with the load Remains constant at all loads 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 When pull-out torque occurs in a synchronous motor, the poles of the rotor are _______ None of the listed here Coincident with statorbpoles Mid way between N and S poles of stator 45° (electrical) behind stator poles None of the listed here Coincident with statorbpoles Mid way between N and S poles of stator 45° (electrical) behind stator poles ANSWER DOWNLOAD EXAMIANS APP
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