A 15hp, 440V, 1250rpm separately excited dc motor draws 30A atrated load. The no-load current is 5A. The armature resistance is0.8ohms. Consider that the rotational losses(core+mechanical) areproportional to the speed. The rated field losses are equal to500W. The field current is kept constant. The machine is notsaturated. For a 220V armature voltage, the recorded armaturecurrent is 25A. Find
a) the motor speed
b) the electromagnetic power and torque
c) the shaft power and torque.