Hi I'm thinking about making an instrument to show the force on a wire carrying electric current for students in lab. A normal wire which levitates from ground after it has current flowing in it. We have the following equations F = ILBsin(a) W = ALg 'A' being the mass of unit length of the wire. We will make the magnetic field perpendicular to the current flow so a=Pi/2 and sin(a)=1 and I want the wire to be suspended above the ground so in equilibrium we must have: F = W ILB = ALg IB = Ag Since g and A are constant in this device what I will need to do is playing with magnetic field and electric current. I'm not very familiar with the Earnshaw theorem but I know if I use an AC current this is doable. I can use normal power outlets (220 V in this case) but I don't know how to create the uniform magnetic field needed. Are natural magnets (Like Neodymium magnets) better or a magnetic field generated by another wire or coil? Is there any easier way to do this? What are notes to keep in mind in this experiment?