Question

What is the formula for the mmf required for stator teeth?

(a) mmf required for stator teeth = mmf per metre + depth of stator slots

(b) mmf required for stator teeth = mmf per metre * depth of stator slots

(c) mmf required for stator teeth = mmf per metre / depth of stator slots

(d) mmf required for stator teeth = mmf per metre – depth of stator slots

I have been asked this question during an online exam.

My doubt stems from No Load Current in section Three Phase Induction Motor of Design of Electrical Machines

Answer 1

Correct option is (b) mmf required for stator teeth = mmf per metre * depth of stator slots

To elaborate: First the mmf per meter is obtained separately from its design equation. Then the depth of the stator slots is obtained and the product of both gives mmf required for stator teeth.