Showing posts with label permittivity. Show all posts
Showing posts with label permittivity. Show all posts

Saturday, 30 December 2017

Gauss's Law: definition, explanation, formula

Definition:

"Gauss's Law states that, Electric flux around a closed surface is depends upon charged enclosed in that surface and permittivity of free space."

Explanation:


Gauss's law states tell us about electric flux through some closed surface or area,
Electric flux through some area depends upon the charge enclosed by that area and the permittivity of free space in that area.
consider there is a closed sphere and there is charge enclosed in it, the flux out of it or the electric field out of the whole area could be determined with the help of Gauss's law.
Consider we wan to find the electric flux through the green planer area, then it will be simple that electric field lines multiplied by area perpendicular to the lines.
But when there comes a closed surface then there is nothing best except Gauss's law to find electric flux through closed surface (enclosed charge.)
It is not necessary that the surface should be closed sphere it could be any type of closed surface. And we will use Gauss's law to determine the electric flux through it.


Formula:


Mathematically we can determine the electric flux through closed surface by formula,

Where Q is the amount of charge enclosed and Ɛ is the permittivity of free space and 𝛟 is electric flux through the surface.


Electric flux density, definition, explanation

Definition:

"Electric flux density is the electric flux passing through some unit area, and its direction is perpendicular to that unit area."

Explanation:

"Electric flux density", when we break down this sentence into "electric flux" and "density".
Then it is easy to understand that, the density of electric flux across some area. Consider there is a unit area shown below.


Electric flux is passing through this, in direction perpendicular to the unit area. The amount of electric flux passing through this unit area, in direction perpendicular to the unit area is called Electric flux density.


Formula:

When we write mathematically the electric flux density it is equal to the product of electric field E and permittivity of material.

                                                                           D=Ɛ.E
Unit:
The unit of electric flux density is coulombs per meter squared.