1. The problem statement, all variables and given/known data An infinitely long thin metal strip of width w=12cm carries a current of I=10A that is uniformly distributed across its cross section. What is the magnetic field at point P a distance a=3cm above the center of the strip? 2. Relevant equations dB = (μ0*dI)/(2*∏*r) 3. The attempt at a solution I evaluate the integral: ∫(μ0*I)/(2*∏*w)*(dr/r) I am unsure of the limits and cannot get the correct answer.