why is the efficiency of a generator more than that of motor? also is there any significance for the gap between the efficiency curve of a generator and a motor. if so, what is the significance?

 

the generator windings are made of more thicker windings hence have lesser resistance and hence lower copper losses

in a motor the armature produces back emf which tries to oppose the motion of the motor (there are two opposing voltages )
but in generator there are no opposing voltages

also the leakage of magnetic flux produces power losses in a motor but the leakage of the flux produced by the field winding in generator is minimum and also not so critical and so it does not pose a problem to lose some flux

 

yeah.. in case of swinburnes test we consider the same dc machine as generator and motor... then there wil be no difference in the construction. then how can we give a reason for max efficiency?

 

but in generator there are no opposing voltages

?

Not what I heard