1. A 400-V DC shunt motor has ?eld and armature resistances of respectively 100 and 0.1 Ω. If the motor absorbs 40 kW from the electric grid, calculate:
(a) the line, armature, and ?eld current
(b) the electromotive force
(c) the ef?ciency
2. The 400-V DC motor of the previous exercise is running at 1100 rpm and absorbing a line current of 80 A. Calculate the torque developed and the ef?ciency.