Two independent single phase semiconverters are supplying the armature and field circuits of a separately excited dc motor for controlling its speed. The firing angle of the converter supplying the field adjusted such that maximum field current flows. The machine parameters are armature resistance = 0.25 Ω, field circuit resistance 147 Ω, motor voltage constant K = 0.7032 V/A *rad/s. The load torque is T = 45 Nm at 1000 rpm. The converters are fed from a 208 V, 50 Hz ac supply, and the friction and windage losses are neglected. The inductance of the field and armature circuits is sufficient to make the armature and field current continuous and ripple free. Determine (a) The field current (b) The delay angle of the armature converters (c) The input power factor of armature circuit converters.