If I have two parallel wires x distance apart in a uniform magnetic field, how would I find the force exerted on a 3rd wire y by z distance away? Is this the time to use the formula for force per unit length?

Question

anonymous · Answer

If both A and C have the same magnitude I but are in opposite directions, the force between them should be 0 right? Does this meant that the force on D due to both A and C will also be 0 since it is an equal distance from both A and C? Or should I be going along the route of calculating A's force on C and C's force on A and somehow relating that to D?

anonymous · Answer

We should first have our symbols clearly stated. I am assuming that your A, C, and D are the three wires. So the first question is, do they all have the same current? 
The next point I make is that opposite currents in two different wires do not give zero force. In fact the two wires repel each other with a force which you can calculate using the formula for the force per unit length. 
I also could not clearly understand where the third wire is located. If you could state that clearly, I can help. Wherever it is, you have to calculate the total force on it by calculating the force due to each of the first two wires, using the force per unit length formula, and then adding the two forces as vectors.