Image current inclusion in the permeable sphere

Abstract

An interesting property of the magnetostatic image theory for a superconducting sphere in the field of a static circular current loop with its axis radial to the sphere is pointed out: the magnetic field outside the superconducting sphere remains unchanged if the superconductor is replaced by a permeable sphere with an embedded current loop which coincides with the image current for the superconducting sphere case. An alternative path for reaching the conclusion is proposed as an exercise for the student. © 2006 IOP Publishing Ltd.