1.A DC Motors A 4-pole, 250 V, wave-connected shunt motor gives 10 kW when running at 1000 r.p.m. and drawing armature and field currents of 60 A and 1 A respectively. Analyse the efficiency of the motor if it has 560 conductors, armature resistance of 0.2 ohm and assume a voltage drop of 1 V per brush