A DC shunt motor drives a centrifugal pump at a speed of 1000
rpm when the terminal voltage and line currents are 200 V and 50 A,
respectively. Given the armature resistance, Ra = 0.1 ohm and field
resistance, Rf =100 ohm. Design a circuit which the speed of the
motor can be controlled by using the added resistance method to the
armature circuit and the maximum starting current is 120 A. Next,
if the added resistance in the designed...