Depending on the nature of the surface charge density is given as the following
Linear Charge Density
where q is the charge and l is the length over which it is distributed
S.I unit of Linear charge density is coulomb/m
Surface Charge Density
σ = q / A
where q is the charge and A is the area over which it is distributed
S.I unit of Linear charge density is coulomb/This is the rendered form of the equation. You can not edit this directly. Right click will give you the option to save the image, and in most browsers you can drag the image onto your desktop or another program.
Volume Charge Density
ρ = q / v
where q is the charge and V is the volume over which it is distributed
S.I unit of Linear charge density is coulomb/This is the rendered form of the equation. You can not edit this directly. Right click will give you the option to save the image, and in most browsers you can drag the image onto your desktop or another program.
Solved Example
Find the charge density if a charge of 8 C is present in a cube of 4 m3
Solution
Given :
Charge q = 8 C
Volume v = 4 m3
The charge density formula is given by
ρ = q / v
= 8 / 4
Charge density ρ = 2 C/m3