Question

If the machine size increases, the three phase alternator resistance _______ and synchronous reactance _______

(a) increases, decreases

(b) decreases, increases

(c) remains constant, decreases

(d) decreases, decreases

The question was posed to me in an online interview.

This question is from Voltage Regulation of an Alternator in portion Synchronous Generators of Electrical Machines

Answer 1

Right choice is (a) increases, decreases

For explanation I would say: If the machine size increases, the copper amount will increase but the air gap will also increase having more reluctance so the reactance will reduce.