permittivitást

Permittivitas is a fundamental property of a dielectric medium that describes its ability to reduce the electric field strength within it. More formally, it is the ratio of the electric displacement field to the electric field. It quantifies how an electric field affects, and is affected by, the dielectric material that constitutes it. In essence, when a dielectric material is placed in an electric field, its constituent molecules polarize, meaning their positive and negative charges separate slightly, creating tiny electric dipoles. These induced dipoles generate an internal electric field that opposes the external field, thereby reducing the net electric field within the material.

Permittivity is often denoted by the Greek letter epsilon, $\varepsilon$. In a vacuum, the permittivity is called the permittivity of free space, denoted by $\varepsilon_0$. For any material, its permittivity is usually expressed as a relative permittivity, also known as the dielectric constant, $\varepsilon_r$, which is the ratio of the material's permittivity to the permittivity of free space: $\varepsilon = \varepsilon_r \varepsilon_0$. A high dielectric constant indicates that the material can store more electrical energy in an electric field compared to a vacuum. This property is crucial in the design of capacitors and other electronic components. The unit of permittivity in the International System of Units (SI) is farads per meter (F/m).