Consider a circular ring of wire of radius a that resides in the x-y plane through the origin. The center of the ring coincides with the origin and you can regard the thickness of the wire to be infinitesimal.
a. Given that a current I flows in the ring, find an expression for the current density J.
∫B(r).dl = μ∫J(r).da
The Attempt at a Solution
ok, I know J(r)=Io * δ(x)*δ(y) z
How do I get this in cylindrical coordinates (ρ,θ,z)?