Electrostatics
5.0 Continuous charge distribution
5.0 Continuous charge distribution
Depending on the dimension of a body, three types of continuous charge distribution are,
- 1-D body (rod): Linear charge density
- 2-D body (film or lamina): Surface charge density
- 3-D body: Volume charge density
5.1 Linear charge density
Charge per unit length is known as linear charge density.
It is denoted by symbol $\lambda $. $$\lambda = \frac{{{\text{Charge}}}}{{{\text{Length}}}}$$
Its SI unit is $C{m^{ - 1}}$.
It is used for 1-D body.
Example: Rod
5.2 Surface charge density
Charge per unit area is known as surface charge density.
It is denoted by symbol $\sigma $. $$\sigma = \frac{{{\text{Charge}}}}{{{\text{Area}}}}$$
Its SI unit is $C{m^{ - 2}}$.
It is used for 2-D body.
Example: Lamina, film, thin plate, spherical shell, cylindrical shell etc.
5.3 Volume charge density
Charge per unit volume is known as volume charge density.
It is denoted by symbol $\rho $. $$\rho = \frac{{{\text{Charge}}}}{{{\text{Volume}}}}$$
Its SI unit is $C{m^{ - 3}}$.
It is used for 3-D body.
Example: Solid cone, solid sphere, solid cylinder etc.
