1. The problem statement, all variables and given/known data a straight conductor carrying 5A is separated by 10cm from a second parallel conductor carrying 10A in the same direction. at what distance from the first conductor (along the line connecting the two conductors) is the magnetic field zero? 2. Relevant equations F_2 = I_2 L X B_1 = [mu_0(I_1)(I_2)L] / 2(pi)d where F_2 is force on conductor 2, mu_0 is 4(pi)*10^-7 constant, d is distance between conductors, I is current, L is length of conductor 3. The attempt at a solution since i need to find the distance when B_1 is zero, i set B_1 = zero and attempted to solve for d, the thing is since when B_1 is zero it makes the left hand side equal to zero thus it is impossible to solve for d F_2 = I_2 L X B_1 = [mu_0(I_1)(I_2)L]/2(pi)d I_2 L X B_1 = [mu_0(I_1)(I_2)L]/2(pi)d I_2 L X 0 = [mu_0(I_1)(I_2)L]/2(pi)d 0 = [mu_0(I_1)(I_2)L]/2(pi)d 0 = mu_0(I_1)(I_2)L where mu_0 = 4pi*10^-7, I_1 = 5A, I_2 = 10A, L is constant i think my approach is wrong because i did not use the 10cm specified in the problem, am i supposed to use I_1, I_2 and d = 10cm =0.1 m to solve for F_2 first? then do i compare that to something? substitute?