A 440-V shunt motor has armature resistance of 0.8 Ω and field resistant 200 Ω. What will be the back e.m.f when giving an output of 7.46 kW at 85 percent efficiency

Q. A 440-V shunt motor has armature resistance of 0.8 Ω and field resistant 200 Ω. What will be the back e.m.f when giving an output of 7.46 kW at 85 percent efficiency.

A.            567.2 V

B.            345.4 V

C.            425.8 V

D.            645 .34 V

Answer: 425.8V