Adc motor with its rotor and field coils connected in series has an internal resistance of 3.2 ω. when running at full load on a 120-v line, the emf in the rotor is 105 v.

Missing question: what is the current drawn by the motor from the line?

Solution:
The potential difference between the two ends of the motor is

where  is the emf, I the current and r the internal resistance of the motor.

By re-arranging the equation and using the data of the problem, we can solve to find the current I: