On certain properties of the electric vector potential in eddy-current problems. Part 2

The boundary-value problem for eddy currents induced in a magnetic solid by an external magnetic field is considered. It is shown that the Lorentz or Coulomb condition in general cannot be applied for systems comprising magnetic solids of finite extents. These conditions are applicable for systems comprising nonmagnetic solids. Therefore the nonhomogeneous diffusion equation can be derived only for the electric vector potential in systems comprising non-magnetic solids.