(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A bar of soft iron of cross sectional area A and relative permeability μ is bent into

a ring of radius R. The bar is wound with n turns of a wire carrying a current I. Deduce a value

for the magnetic field in the iron, explaining your assumptions.

(b) A narrow gap of width w is sawn into the ring. Find the magnetic field in the gap.

2. Relevant equations

3. The attempt at a solution

For part a. I used Ampere's Law with H to get

H = nI/(2*pi*r)

B = μμ0nI/(2*pi*r)

But part b? I thought of trying to do some sort of superposition. Perhaps working out M in the original problem, and then doing the field due to the original problem plus the field due to a small chunk with opposite magnetization. Is this at all on the right lines?

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# Magnetization, coil question

Can you offer guidance or do you also need help?

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