**What is Permittivity of Free Space?**

**Permittivity**is an electric constant that measures the ability of a medium to store energy within the medium. If the medium is a vacuum then it is called the

*permittivity of free space/vacuum (𝜀o).*

The value of (

*𝜀o*) is measured by the formula -Where

*c*is the**that has a defined value of***speed of light**299792458 m/s*and*μ0*is called the**( commonly known as***magnetic constant***) that has an approximate value of***permeability of free space**4π × 10-7 N/A**2*. So*εo*can be expressed numerically as**Units of Permittivity of Free Space**

We all know from Coulomb's law that

We know that in the SI unit system the unit of charge is

*, the unit of force is***Coulomb (C)***, and the unit of distance is***Newton (N)****.***meter (m)*Therefore, in the SI unit system, the unit of permittivity of free space (

*𝜀o*) is**Dimension of Permittivity of Free Space**

Similarly,

**Relative & Absolute Permittivity**

We know that when two charges are placed in a vacuum, then the effective force that is working between them is

And if the charges are placed in another medium instead of a vacuum, then the effective force that is working between them is

Now

Here this

*𝜀r*is called*relative permittivity,**𝜀*is called**. and also***absolute permittivity/permittivity of the medium**𝜀o*is the**.***permittivity of free space***Read next:**The Vector form of Coulomb's Law