What is Permittivity?

Permittivity is the measurement of passage of electric field through a material which in turn measures the polarisibility of the material. The property of a vacuum to allow electric fields is known as free space permittivity. When it comes to material media, the permittivity changes since each medium has a unique capacity to allow an electrical field through it; however, since empty space is devoid of matter and fields, the permittivity remains constant. As a result, open space has a constant permittivity with a standard value. The constant has a relative standard uncertainty of 1.5 × 10^-10 and is roughly equivalent to 8.854 x 10^-12 F/m (farad per meter). The standard unit of capacitance used to measure a material’s capacity to store an electric charge is the farad.

The formula for Permittivitty is given as

ε = D/E

where,

• ε is Permittivitty
• D is Displacement Electric Field
• E is Electric Field

The permittivity of unoccupied space is represented by ε₀, or epsilon-naught, which is also related to capacitance and the energy stored in an electric field. Please take note that, unlike metals, dielectrics have no free electrons that may go through the material, therefore when we place them in an electric field, almost no current flows in them. Rather, there is electric polarization. Accordingly, a substance’s permittivity is its capacity to permit the electric field to flow through it.

Permittivity of Free Space

A physical constant that represents the capacity of electrical fields to flow through a classical vacuum is called the permittivity of free space. Free space has a permittivity of its own, much like every other medium does. The vacuum is the medium in this instance. Hence, Permittivity of Free Space is also called Permittivity of Vacuum. The electric constant, or vacuum permittivity, is another name for the permittivity of free space. In a certain medium, such a vacuum, permittivity is the constant that determines the proportionality between electric displacement and electric field intensity. The value of Permittivity of free space is 8.854 x 10^-12 F/m. The formula of Permittivity of free space is given as

ε₀ = ε/ε_r

where,

• ε is the Permittivity
• ε_r is the Relative Permittivity

Significance of Epsilon Naught

Some of the important usecase of significance of Epsilon Naught are:

• Epsilon Naught indicates the open space’s or vacuum dielectric permittivity.
• Since space permittivity is a constant, it is frequently utilized in numerical issues.
• Using Coulomb’s law, it is used to determine the force between two charged particles.
• Epsilon Naught is employed to determine an insulator’s capacitance.
• The dielectric constant of a substance is computed using the value of Epsilon Naught.

Also, Check

• Unit of Electric Charge
• Dielectric and Polarisation
• Electric Field Lines

Epsilon Naught Value is 8.85418782 × 10^-12 m^-3 kg^-1s⁴ A². Epsilon Naught is represented as ε₀ where Epsilon is a Greek letter with 0 as its suffix. Epsilon Naught is used to represent the Permittivity of free space and permittivity is basically the measure of the polarisibility of a material in the presence of an electric field.

Permittivity simply means, that the greater the value of permittivity the more a material will polarise in the presence of the electric field. The permittivity of free space is also called the permittivity of the vacuum. In this article, we will learn what is epsilon naught, what is the value of epsilon naught, the dimensional formula of epsilon naught, and its derivation.