(a) An infinitely large film of insulating magnetic material has permeability and thickness h. A uniform...

(a) An infinitely large film of insulating magnetic material has permeability μ and thickness h. A uniform external magnetic field B₀ is oriented perpendicular to the plane of the film. Find the magnetic field B at any point inside the film.
(b) Create a magnetic disk by removing from the film in part (a) all the matter that lies outside a region of radius R >> h (see diagram below). Find B at the center of the disk which remains (to first order in h/R) by subtracting, from the answer to part (a), the magnetic field produced at the center of the disk by the matter outside the disk.

The field of a point magnetic dipole with moment m is

Transcribed Image Text:

Во -R h