Question

What is, neglecting the flux within the wires themselves, the inductance for a length l of two, long parallel wires of radius r, separated by a distance d between their centers, that carry equal

currents in opposite directions?

Answer 1

Hey there!

I have drawn the diagram of the electric and the magnetic fields of the parallel wires which carry current in the opposite direction. Since they are in opposite directions I have given them as positive and negative.

Here I have drawn the red lines as the magnetic flux and the black lines as the lines of electric field.

When you could see the electric field lines, they converge from the positive end to the negative end.

When you look at the red lines (magnetic field lines , also known as the magnetic flux) they are found to be in the direction perpendicular to that of the electric field. the magnetic flux meets at the center and hence they negate each other and pushes the wire in opposite directions.

I hope the explanation helps... Feel free to comment and discuss further.... Cheers :)