A synchronous motor with negligible armature resistance runs at a load angle of 20° at the rated frequency. If supply frequency is increased by 10%, keeping other parameters constant, the new load angle will be
A. 16°
B. 18°
C. 20°
D. 22° [U.P.S.C. I.E.S. E.E.-II, 1999]
Answer:C
A synchronous motor with negligible armature resistance runs at a load angle of 20° at the rated frequency. If supply frequency is increased by 10%, keeping other parameters constant, the new load angle will be
A. 16° B. 18° C. 20° D. 22° [U.P.S.C. I.E.S. E.E.-II, 1999]