# Electric field along a wire and load

I have referred to many books and all of them apply loss in potential across a resistor only in case of circuits. However, the electric field is present in the whole conductor. Hence the electrons should lose potential all along the wire and not only across the resistor?

P.S. There could be some assumption in this topic and I'm apparently unaware of it.

• Nobody makes that assumption outside of simplified student exercises. Neither engineers nor working experimental physicists treat wires as ideal, lossless conductors. Conduction in materials (electrical and heat) is one of the most important topics in solid state physics, with a wide range of theoretical work to understand it. – CuriousOne Jan 12 '16 at 15:14

Ok, that's a bit tricky: These books propably use the assumption that the wire is a perfect conductor. What follows is that any difference in the electric potential $\Phi$ allong the potential will create a field (as you said). BUT, and here is the clue: Since it is a perfect conductor, and electrons have little mass compared to the force that the electric field generates, these books (and pretty mutch everyone) makes the assumption that the electrons are being distributed along the conductor in a way that there is no electric Field anymore.