Permittivity

There are three things

• Absolute Permittivity $ϵ$
• Relative Permittivity ${ϵ}_r$
• Permittivity of free space ${ϵ}_0$

Permittivity of free space

${ϵ}_0=8.854\times 10^{-12}{m}^{-3}k{g}^{-1}{s}^4{A}^2\text{ or }\frac{F}{m}$

“Free space” is a technical word for a space which is free of any induced charges.

Absolute Permittivity

$ϵ={ϵ}_r{ϵ}_o$

Relative Permittivity

Relative Permittivity is defined by ${ϵ}_r=1+{\chi }_e$ where ${\chi }_e$ is the Electric Susceptibility.