1. The problem statement, all variables and given/known data https://dl.dropbox.com/u/63664351/Physics/ELEC1.PNG [Broken] 2. Relevant equations http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/wirfor.html https://dl.dropbox.com/u/63664351/Physics/Magnetioc%20Force%20Between%20Wires.PNG [Broken] 3. The attempt at a solution We want the tension to be zero. But since the force of gravity going downward, then magnetic force in wire 2 must goes up. But magnetic force in wire 2 goes up only if current going to the right and magnetic field goes entering the screen . My question. How do I know for sure that the magnetic field is entering the screen, not out of the screen? Also from the relevant equation image there is something I don't understand in wire 1. Isn't by right hand rule, if thumb is thrust and middle finger the current, then B must be out of the screen? but why in wire one the direction is looping?