Property of a Material that determines how much electric flux density will build up upon the application of an electric field.
Permittivity of free space, εO.
A fundamental constant of nature
εO=8.85 x 10-12farad meter -1
Related to the permeability of free space μO
and the speed of light c
The relative permittivity εr (also known as the dielectric constant) of any material of permittivity ε is given by ε/εO.
The electric flux density D and the electic field E are related by the permeability.
D=ε E=εr εO E