Permittiivsus

Permitiivsus is a fundamental property of a material that describes how it affects an electric field. More specifically, it quantifies how easily an electric field can be established within a material. When a material is placed in an external electric field, its constituent atoms or molecules may become polarized. This polarization creates an internal electric field that opposes the external field. The permitiivsus of the material determines the extent of this opposition.

In vacuum, the permitiivsus is denoted by $\epsilon_0$ and is a fundamental physical constant. For any material medium, the permitiivsus is typically expressed relative to the vacuum permitiivsus as the relative permitiivsus, $\epsilon_r$. This relative value is a dimensionless quantity. The absolute permitiivsus of a material is then given by $\epsilon = \epsilon_r \epsilon_0$. Materials with high relative permitiivsus, often called dielectrics, can store more electrical energy in an electric field compared to materials with low permitiivsus. This property is crucial in the design of capacitors. The behavior of electric fields in different media is governed by Maxwell's equations, where permitiivsus plays a key role.