# Why don't charges on surface of current carrying wire move?

When a steady current flows through a wire, there is usually charges on the surface of the wire. These surface charges have an nonuniform distribution so that the electric field inside the wire is uniform and parallel to the wire.

But… If I understand correctly due to the nonuniform surface charge distribution there should be tangential electrical field on the surface of the wire, which is directed same as the current. If so, why don’t surface charge move in same direction as free charges in the bulk of conductor. In other words, what force makes the charges on the wire surface be stationary?

• Why do you think this being true?"there is usually charges on the surface of the wire." Commented Aug 8 at 10:07
• @trula that is part of standard physics explanation of how wires actually work. See the huge debate that Veritasium kicked off with the "energy does not flow in wires" video. Commented Aug 8 at 10:11
• > "why don’t surface charge move in same direction as free charges in the bulk of conductor." I think that is an approximation. Maybe they do move, but the surface is pretty thin and has high resistance, unlike the wire inside, so in usual DC conduction, surface current is considered negligible. Commented Aug 8 at 13:44

The entire wire feels a constant $$\vec E=\rho\vec J$$ field, and the constant $$\vec J$$ flow of current means that every bit of the surface charge that flowed tangentially to the next bit of the wire, is also being replaced by the charge that is coming from the back that flows into it. This steady state of affairs means that the non-uniform surface charge is easily kept there, and does not diminish away, at least until the power supply or battery stops supplying either of voltage or current.