Question about electricity and magnetism

[Andrew Shaw]

Why is it that 2 wires carrying parallel current attract each other i think they should repeal imagine 2 wires carrying electrons to the left then the current is to the right, in the reference frame of the moving electrons it seems like the electrons on the other wire are not moving so the should create a static electric field that should repeal the electrons in the wire using that particles of same charge repeal each other this has been bothering for a long time and i would appreciate i somebody could help me thanks in advance

 

[Bob S]

When there are parallel currents in two parallel wires, they attract one another. This also true if the observer is in a moving frame where the current in one wire is zero, because in doing the transform, the azimuthal magnetic fields in BOTH wires in the rest frame are transformed to radial electric fields in the observer's frame, even if the current in one wire is zero. These two electric fields either repel or attract. See
http://pdg.lbl.gov/2009/reviews/rpp2009-rev-electromag-relations.pdf

 

[astrokreng]

The phenomenon of two wires carrying parallel currents attracting each other is known as the Ampere's force law. This law states that two parallel current-carrying conductors will experience an attractive force between them, with the magnitude of the force increasing as the current and the distance between the wires increases.

This may seem counterintuitive, as you have correctly pointed out that particles with the same charge should repel each other. However, in this case, the attractive force is not due to the charges on the wires themselves, but rather the magnetic fields they create.

When an electric current flows through a wire, it creates a magnetic field around it. This magnetic field interacts with the magnetic field of the other wire, resulting in an attractive force between the two wires. This is similar to how two magnets with opposite poles attract each other.

In the reference frame of the moving electrons, as you mentioned, the electrons in the other wire may appear to be stationary. However, this is because they are moving at the same velocity as the electrons in the first wire, so their relative motion cancels out. This does not change the fact that both wires are still carrying a current and creating a magnetic field, which results in the attractive force between them.

I hope this explanation helps to clarify the concept of Ampere's force law and why two parallel current-carrying wires attract each other. Keep asking questions and exploring the wonders of electricity and magnetism!