1. The problem statement, all variables and given/known data A single-turn wire loop produces a magnetic field of 41.2 μT at its center, and 5.15 nT on its axis, at 20.0 cm from the loop center. Find loop raidus and current. 2. Relevant equations F = qv x B 3. The attempt at a solution I tried to use the above equation, but could not figure out how to use it to find a radius r. What must be done in order to get an equation with such variables? For current I believe F = IL x B should work, but I don't know if radius r is necessary.