Question

In a DC machine, what is the torque induced beyond the pole shoes?

(a) 0

(b) 2/π *∅*i

(c) π *∅*i/2

(d) Can’t be calculated

The question was posed to me during an internship interview.

I want to ask this question from EMF and Torque Production in division Circuit Model, Emf and Torque of DC Machines

Answer 1

Right option is (a) 0

Explanation: In a construction of a DC machine poles are located in magnetically neutral region. The magnetic field at the pole terminals in a DC machine will be equal to 0. Thus, cross product with the current flowing through the armature yields zero.