A 300 V, d.c. shunt motor runs at a speed of 800 rpm when driving a constant-torque load. The armature resistance is 0.5 2 and the field resistance is adjusted to give 3A in the field circuit. Under certain load condition the motor draws a line current of 20 A. (a) Calculate the resistance that must be added to the armature circuit to reduce the speed of the motor to 400 rpm. (b) What is the value of the additional resistance that must be inserted in the armature circuit to make the motor operates in the stalling condition?

A 300 V, d.c. shunt motor runs at a speed of 800 rpm when driving a constant-torque load. The armature resistance is 0.5 2 and the field resistance is adjusted to give 3A in the field circuit. Under certain load condition the motor draws a line current of 20 A. (a) Calculate the resistance that must be added to the armature circuit to reduce the speed of the motor to 400 rpm. (b) What is the value of the additional resistance that must be inserted in the armature circuit to make the motor operates in the stalling condition?

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter5: Resistors

Section: Chapter Questions

Problem 1PA

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