A dc shunt motor drives a centrifugal pump at a speed of 1000rpm when the terminal voltage and the line currents are 200V and 50A, respectively. The armature and field resistance are 0.1 ohm and 100 ohm respectively.
A.)Design a starting resistance for a maximum starting current of 120A in the armature circuit.
B.)What resistance should be added to the armature current to reduce the speed to 800 rpm?
C.)If the terminal voltage is reduced by 25%, what is the speed of the motor?