Question

What should be the range of the current per brush arm?

(a) limited to 400 A

(b) limited to 200 A

(c) limited to 100 A

(d) limited to 300 A

This question was posed to me in a job interview.

My doubt stems from Selection of Number of Poles in division Thermal Design Aspects of Electrical Machines & D.C of Design of Electrical Machines

Answer 1

Right answer is (a) limited to 400 A

To explain: The current per brush arm should be limited to maximum of 400 A. If the limit gets exceeded then there occurs damage to the machine.