1. The problem statement, all variables and given/known data If a uniform current with current density s flows around a tube of radius a-- so it is a surface current, how might I find the magnetic field at some arbitrary position vector r?* 2. Relevant equations Biot-Savart? 3. The attempt at a solution I am guessing Biot-Savart? Or is there a simpler way since it has nice symmetry?