Q
If excitation of a synchronous motor running with a constant load is decreased from its normal value, ignoring effects of armature reaction, it leads to____________?
AA. Increase in both armature current and power factor angle
BB. Increase in back e.m.f. but decrease in armature current
CC. Increase in both armature current and power factor which is lagging
DD. Increase in torque angle but decrease in back e.m.f.
Correct Answer:
A. A. Increase in both armature current and power factor angle