Question

What happens if the field form is symmetrical about the pole axis?

(a) north and south pole of a machine are similar

(b) no harmonics

(c) no cosine terms

(d) north and south pole of a machine are similar, no harmonics, no cosine terms

I had been asked this question during an online exam.

The origin of the question is Field Form, Harmonic Analysis of Flux Distribution Curve topic in portion Principles of Magnetic Circuit Design of Design of Electrical Machines

Answer 1

Right answer is (d) north and south pole of a machine are similar, no harmonics, no cosine terms

Explanation: If the field form is symmetrical about the pole axis the north and south pole of a machine are similar. As the poles are similar, no harmonics and no cosine terms and the constant term is zero.