A very thin, infinitely long metal sheet lies in the xy-plane,

Question

between x = -w and x = w. A current of density h A/m flows
in the +y-direction. What are the magnitude and direction
of the magnetic field at a distance z « w above and
below the sheet? Neglect end effects.

Answer 1

I think B = (mu)h
where mu is the permeability of free space. Direction is +x above and -x below.