Question

Consider a single phase synchronous machine of cylindrical rotor type. A single phase supply is given to the stator winding and a voltmeter is connected across rotor winding. For what value of θr, the voltmeter reads maximum?

(a) 90°

(b) 0°

(c) 45°

(d) 30°

I have been asked this question in homework.

Enquiry is from Elementary Synchronous Machines topic in chapter Basic Concepts in Rotating Machines of Electrical Machines

Answer 1

Right answer is (b) 0°

To elaborate: When θr=0, the flux linkages with the rotor are maximum, and this is indicated by a maximum voltmeter reading.