A 100 hp, 220 V, 1200 rpm DC shunt motor with an armatureresistance of 0.05 ? and a field resistance of 50 ?. The motor hascompensating windings, so armature reactance can be ignored.Mechanical and core losses may be ignored also. The motor isdriving a drilling machine, TL ? (1/n). The motor is driving a loadwith a line current of 120 A and an initial speed of 1200 rpm.Assume Linear Magnetization curve
i. What is the motor speed if the field resistance is increased to55?? While supplying a constant-torque load
ii. Calculate the motor speed as a function of the fieldresistance, assuming a constant-Load Torque. Plot the motor speedas a function of the field resistance.
