I need help working this one out. Would really appreciate the help. An 80-V DC motor has a constant field flux (separately excited) and a nameplate speed of 1150 rpm with 710 W output power. The nameplate armature current is 10 Amps and the no-load current it 0.5 A. Assume constant rotational losses. a) Determine the armature resistance b) Estimate the rotational loss c) Find the machine constant in V/(rad/s) d) What is the no-load speed in rpm e) Find the effieciency at nameplate load, including field circuit losses of 30 W. I know the formula for part a) is Ra=(V-E)/Ia, but how do you find E?