A perfectly dimagnetic sphere has a small spherical cavity at its centre, which is filled with a paramagnetic substance. The whole system is placed in a uniform magnetic field B⃗ . Then the field inside the paramagnetic substance is:

Question

G1 Physics · Accepted Answer

A perfect diamagnet excludes magnetic flux. A small central cavity inside the perfectly diamagnetic sphere is magnetically shielded from the external field in the ideal limit, so the field in the paramagnetic filling is zero. Hence A.