A dc series motor of 230 V, 12 hp, 1200 rpm is connected to a 230 V supply. It draws a current of 40 A, and rotates at 1200 rpm. Ra = 0.25 ohms and Rs = 0.1 ohms. Assume magnetic linearity.
Determine the power and torque developed by the motor.
Determine the speed, torque, and power if the motor draws 20 A.