Question

for a synchronous motor, its power factor __________

(a) improves with increase in excitation and may even become leading at higher excitations

(b) is independent of its excitation

(c) decreases with increase in excitation

(d) increases with loading for a given excitation

This question was addressed to me in an internship interview.

Question is taken from Two Reaction Theory of Salient Pole Machines topic in division Synchronous Machines of Electrical Machines

Answer 1

Right option is (a) improves with increase in excitation and may even become leading at higher excitations

The best I can explain: A per the inverted V-curves it can be easily concluded that as the excitation increases synchronous motor becomes leading.