Question

There are three long parallel wires arranged so that, in cross-section, they occupy the points of an equilateral triangle. Is there any way to arrange the currents so that all three wires attract each other?

Answer 1

Yes, there is such a way.

Step-by-step explanation:

If currents flow in the same direction in two or more long parallel wires, there will be an attractive force between the wires. If the current flows in different directions, there will be a repulsive force between the wires. In this case, these three parallel wires, can be be made to carry current in the same direction, creating an attractive force between all three wires.

Note that it is not possible to have at the least one of them carry current in the opposite direction and still have an attractive current between them.