A d.c machime has a torque angle of 90 degree. When rotating the at 3000rpm with a field current of 1A, the generated voltage is 100v. When the two windings are connected to a a.c supply of 50hz, the field current is 0.1A, the armature current is 100A and the phase difference between them is 60 degree. calculate the average torque and maximum torque?