I've recently stumbled on an electromagnetics problem that I don't quite understand.
There is an infinite wire carrying current I that is placed inside a medium with magnetic permittivity μ1. At a distance d from the wire, there is a boundary between two mediums and a second medium with permittivity μ2 starts.
a) Find vectors B and H.
b) Find the force acting on a unit length of the wire.
I've translated this to english, so if anything isn't clear, I'll try to explain it.
From what I understand. Since the mediums are linear and the wire is infinite. The H field can be calculated using Ampere's law and it will be equal to $H = \dfrac{I}{2\pi r}$ for $r > 0$ and $H = 0$ for $r = 0$. Then the B field in both mediums will just be equal to $μH$. I also think that there will be a bound surface current density at the boundary between the two mediums, but the Lorentz force is dependent on the field B and since for $r = 0$ where the wire is, it's equal to 0, I don't get where a force acting on the wire would come from.
