**1. The problem statement, all variables and given/known data**

Find the magnetic flux through a circle in the xz plane of radius "a" due to a wire. . The center of the circle is (b,0,0).

**2. Relevant equations**

Well I found the magnetic field to be proportional to

[tex]\frac{1}{\rho}[/tex]

That field has only a component in the phi direction.

Where rho and phi are cylindrical coordinates.

**3. The attempt at a solution**

I can't figure out the limits of integration for anything unless it's rectangular coordinates, but those become very messy and I obtain an integral which is clearly wrong. I KNOW the answer should reduce to something "nice."

I know I'm missing something stupid here.