6.29 A 40-hp, 320-V DC shunt motor has armature and field winding resistances of 0.2Ω and 115Ω, respectively. At no-load and rated voltage, the speed is 1,200 rpm and the motor draws a line current of 5A. If load is applied to the motor, its speed drops to 1,100 rpm. Assume that the effects of armature reaction are negligible. At this load, determine:
1. The armature current and the line current
2. The developed torque
3. The horsepower output assuming the rotational losses are constant at 350W