1. The problem statement, all variables and given/known data You have a 1.10-m-long copper wire. You want to make an N-turn current loop that generates a 0.800 mT magnetic field at the center when the current is 1.50 A. You must use the entire wire. What will be the diameter of your coil? 2. Relevant equations B = (mu_0)(n)(i)/(2r) 2(pi)(r)(n) = 1.1 ? 3. The attempt at a solution 0.8 * 10^-3 = 4(pi)*(10^-7)n(1.5)/2r find n/r from this then: nr = 1.1/2(pi) combine the two you get r^2 = ... I'm not sure if im going right here although I'm quite positive.. Need help on the calculations.