Fall 2003 14 Em

A superconducting slab occupies the region $z < 0$. A long straight wire is parallel to the $\hat{y}$ axis and lies at $x = 0$ and $z = h$; assume that the wire carries current $I$ in the $+\hat{y}$ direction.

1. Determine the magnetic field in the region above the superconductor, taking into the account the fact that the superconductor excludes any magnetic field from its interior.
2. Determine the surface current on the superconductor.
3. Determine the force per unit length on the wire, stating explicitly whether the wire is attracted to or repelled from the surface.