Synchronous Motors While running, a synchronous motor is compelled to run at synchronous speed because of _______ Compulsion due to lenz's law Damper winding in its pole faces Induced emf in rotor field winding by stator flux Magnetic locking between stator and rotor poles Compulsion due to lenz's law Damper winding in its pole faces Induced emf in rotor field winding by stator flux Magnetic locking between stator and rotor poles ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors When pull-out torque occurs in a synchronous motor, the poles of the rotor are _______ 45° (electrical) behind stator poles Coincident with statorbpoles Mid way between N and S poles of stator None of the listed here 45° (electrical) behind stator poles Coincident with statorbpoles Mid way between N and S poles of stator None of the listed here ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors The efficiency of a properly designed synchronous motor will usually fall in range 60 to 70% 99 to 99.5% 75 to 80% 85 to 95% 60 to 70% 99 to 99.5% 75 to 80% 85 to 95% ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors When load on a synchronous motor is increased, its armature current is increased provided, it is ______ Under-excited Over-excited Normally excited All of these Under-excited Over-excited Normally excited All of these ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors The standard full-load power factor ratings for synchronous motors are zero or 0.8 leading unity or 0.8 leading unity or zero unity or 0.8 lagging zero or 0.8 leading unity or 0.8 leading unity or zero unity or 0.8 lagging ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors If the field circuit of an unloaded salientpole synchronous motor gets suddenly open-circuited, then it runs at a slower speed it runs at a very high speed it continues to run at the same speed the motor stops it runs at a slower speed it runs at a very high speed it continues to run at the same speed the motor stops ANSWER DOWNLOAD EXAMIANS APP
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