Question

What is specific permeance?

(a) specific permeance is product of permeance of unit length and depth of field

(b) specific permeance is ratio of permeance of unit length and depth of field

(c) specific permeance is the permeance per unit length

(d) specific permeance is the permeance per unit pole

I had been asked this question during an online interview.

My question comes from Specific Permeance & Calculation of Magnetizing Current in portion Principles of Magnetic Circuit Design of Design of Electrical Machines

Answer 1

The correct answer is (c) specific permeance is the permeance per unit length

For explanation I would say: Specific permeance is defined as permeance per unit length. It is also known as the depth of field.