# Skin effect and the eddy currents

I am trying to understand the skin effect, there is a bit in Wikipedia article I don't understand;

"...The change in the magnetic field, in turn, creates an electric field which opposes the change in current intensity. This opposing electric field is called “counter-electromotive force” (back EMF). The back EMF is strongest at the center of the conductor, and forces the conducting electrons to the outside of the conductor, as shown in the diagram on the right."

Why is the induced EMF strongest at the center of the conductor?

• Yep, that's a very poorly thought out explanation, and honestly, I would call it flat out wrong. The current density inside a conductor with skin effect decays towards the inside, and for an infinitely large conductor it would be zero and there would be no fields in there, at all. In technical applications this means that one can use hollow conductors, which can then be cooled from the inside with high pressure water without any significant loss in effective conductivity. – CuriousOne Dec 25 '14 at 13:46

If one evaluates the Ohmic dissipation, (${\bf J}\cdot {\bf E}$) per unit volume, integrated over the depth that the wave penetrates, one finds it is exactly equal to the energy lost deduced from the diminished Poynting vector.