1. The problem statement, all variables and given/known data Different question, same problem. I edited this post from what I orignially posted it as (in which my issue was that I misread the problem). In Figure 29-63, a long circular pipe with outside radius R = 2.4 cm carries a (uniformly distributed) current i = 3.40 mA into the page. A wire runs parallel to the pipe at a distance of 3.00R from center to center. Find the magnitude and direction of the current in the wire such that the net magnetic field at point P has the same magnitude as the net magnetic field at the center of the pipe but is in the opposite direction. 2. Relevant equations Ampere's Law 3. The attempt at a solution I want to find the net field at the center of the pipe. By thinking about it and by looking at equations for B (which have R in the denominator), isn't the magnetic field at the center of the pipe due to the pipe zero? If the field due to the pipe at the center of the pipe is zero, then the wire cannot produce a field at point P that is in the opposite direction than the net field at the center of the pipe. So the net field at center of the pipe cannot be zero? Or where else could I be wrong?