A six-pole, 60-Hz synchronous machine has a rotor winding with a total of 138 series turns and a winding factor kr = 0.935. The rotor length is 1.97 m, the rotor radius is 58 cm, and the air-gap length = 3.15 cm.

a. What is the rated operating speed in r/min?

b. Calculate the rotor-winding current required to achieve a peak fundamental air-gap flux density of 1.23 T.

c. Calculate the corresponding flux per pole.