A shunt-wound dc motor with the field coils and rotor connected in parallel (Fig) operates from a

Question:

A shunt-wound dc motor with the field coils and rotor connected in parallel (Fig) operates from a 120-V dc power line. The resistance of the field windings, RI , is 218 .n. The resistance of the rotor, R" is 5.9 .n. When the motor is running, the rotor develops an emf E. The motor draws a current of 4.82 A from the line. Friction losses amount to 45.0 W. Compute
(a) The field current;
(b) The rotor current;
(c) The emf E;
(d) The rate of development of thermal energy in the field windings;
(e) The rate of development of thermal energy in the rotor;
(f) The power input to the motor;
(g) The efficiency of the motor.