Anyone know how to start this one off. Lost all my notes on dc motors.
Q) A 240V dc shunt motor has an armature and field resistance of 0.2 ohms and 320 ohms respectively. The motor drives a load at a speed of 950 rev/min and the armature current is 50A. Assuming that the flux is directly proportional to the field current, calculate the additional resistance necessary in the field circuit to increase the speed to 1100 rev/min while maintaining the armature current constant.