A large block of permanently magnetised material fills the region is air
PHYSICS · Multi-part · Fermi University Physics · Electricity, Magnetism & Electromagnetism · Magnetic materials · Maxwell's equations and conservation laws
Electricity, Magnetism and Electromagnetism, Ch Displacement current, Maxwell's equations and boundary conditions
Problem
A large block of permanently magnetised material fills the region z<0; the region z>0 is air, which may be treated as vacuum. The magnetisation inside the block is uniform, M=5.0×105Am−1 along +x^, that is parallel to the flat face. Just inside the face the magnetic field is also tangential, B=0.80T along +x^. There is no free surface current on the face, and nothing changes with time.
((a)) Find the magnitude of H just inside the block.
((b)) Hence find the magnitude of B in the air just above the face.
((c)) Find the magnitude and direction of the bound surface current density on the face, and check that it accounts for the jump in the tangential B.