In EM theory concept of skin depth is induced which is a measure of how much a EM wave can penetrate the medium, from it arises the concept of skin effect which is for EM wave but we use this to explain flow of current in conductor (most of the current flows over the skin of conductor at high frequency). But all this was derived for EM wave then why are we using it to explain flow of current,which is not em wave ???
for EM wave then why are we using it to explain flow of current,which is not em wave ???
The current in the wire is actually related to electromagnetic waves around the wire.
It just happens to be easier in many situations to analyze the currents in and voltages on conductive parts of a system than to analyze the fields in the dielectric parts of the system.
But the currents and voltages are inextricably linked to the fields, and in the case of analyzing skin depth it's easier to understand if we analyze the fields instead of the currents and voltages.