#### CHAPTER 8 ELECTROMAGNETIC WAVES

Maxwell’s generalisation of Ampere’s circuital law

The source of a magnetic field is not just the conduction electric current, but also the time rate of change of electric field. Or the total current i is the sum of the conduction current denoted by ic, and the displacement current denoted by,

${\mathrm{i}}_{\mathrm{d}}={\mathrm{\varepsilon }}_{\mathrm{o}}\left(\frac{{\mathrm{d}\mathrm{Ф}}_{\mathrm{E}}}{\mathrm{d}\mathrm{t}}\right)$

That is,

The Amperes circuital law is modified as follows,

This is called Ampere Maxwell law.