At 50% of full load, the armature current drawn by a dc shunt motor is 40 A when connected to a 200 V supply. By decreasing the field flux , its speed is raised by 20%; this also causes a 10% increase in load torque. Calculate the percentage change in field current. The armature resistance including the brushes is 1 ohm. Neglect saturation and armature reaction.

At 50% of full load, the armature current drawn by a dc shunt motor is 40 A when connected to a 200 V supply. By decreasing the field flux , its speed is raised by 20%; this also causes a 10% increase in load torque. Calculate the percentage change in field current. The armature resistance including the brushes is 1 ohm. Neglect saturation and armature reaction.

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter30: Dc Motors

Section: Chapter Questions

Problem 4RQ

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