780 V, 97 A, 1360 rpm separately excited dc motor with armature resistance (Ra) equal to 9 ohms. Calculate back emf developed in the motor when it operates on one-fourth of the full load. (Assume rotational losses are neglected)

• A. equal to 9 ohms. Calculate back emf developed in the motor when it operates on one-fourth of the full load. (Assume rotational losses are neglected)a) 564.75 V
• B. 561.75 V
• C. 562.45 V
• D. 564.75 Vb) 561.75 Vc) 562.45 Vd) 565.12 V