1. The problem statement, all variables and given/known data Two thin wires of length [tex] L_1, L_2 [/tex] were placed perpendicular to each other in half of their lengths. Wires are carrying current [tex] I_1[/tex] and [tex] I_2. [/tex] Find the torque on each of those wires. 2. Relevant equations [tex] \tau = \mu \times B = r \times F [/tex] 3. The attempt at a solution To calculate the force I need the magnetic field, which I don't really know how to calculate in this problem. Calculating the magnetic dipole moment would require surface area, which I guess is zero(wires are infinitely thin) so it's a dead end. In parallel lines problem I could calculate magnetic field and force easily in any point in space, but I guess I can't really do that here because there is no distance between the wires. Where should I start?