A medium which has influence in the characteristics of the fields, when the sources of electric and magnetic fields exist in it.
The medium constructs
relation to describe the fields characteristics namely,
D
= ϵE where, ϵ =
permitivity
B
= µH µ =
permeability
J
= σ E σ =
conductivity
Sometimes we describe
mediums into several titles. Among them our familiar titles are given
below-
Homogeneous medium: It is a medium for which ϵ, µ, σ are constant throughout the medium.
Example- Free space.
Nonhomogeneous medium: It is a medium for which ϵ, µ, σ are not constant and are different
from point to point in the medium. Example- Human body.
Isotropic medium: It is a medium for which at least ϵ is a
scalar constant. Example- Free space.
Anisotropic medium: It is a medium for which at least ϵ is
not a scalar constant.Example- Human body.
Source free region: It is a medium in which there are no
field sources.
