Tru Physics

Permittivity of Free Space

—

by

Tru Physics
in

Introduction

The permittivity of free space, commonly denoted as \varepsilon_0, is a fundamental physical constant that measures the ability of a vacuum to permit electric field lines. It is a crucial parameter in the study of electromagnetism.

Definition and Value

The permittivity of free space is defined as the ratio of the electric flux density \vec{D} to the electric field \vec{E} in a vacuum:

\vec{D} = \varepsilon_0 \vec{E}

The standard value of the permittivity of free space is:

\varepsilon_0 = 8.854187817 \times 10^{-12} \dfrac{\text{F}}{\text{m}}

where F stands for Farads, the unit of electrical capacitance, and m for meters, the unit of distance.

Role in Electromagnetic Waves

In electromagnetic waves, the permittivity of free space appears in the equation for the speed of light in vacuum, which is given by:

c = \dfrac{1}{\sqrt{\mu_0 \varepsilon_0}}

where \mu_0 is the permeability of free space.

Conclusion

The permittivity of free space is a fundamental physical constant that characterizes how an electric field propagates in free space. It is integral to many laws and principles in electromagnetism and is crucial in the study of electromagnetic waves. It is a key parameter for understanding the interaction of electric fields with matter and the propagation of electromagnetic waves.

Do you prefer video lectures over reading a webpage? Follow us on YouTube to stay updated with the latest video content!

Want to study more? Visit our Index here!

Comments

One response to “Permittivity of Free Space”

  1. Ampere’s Law – Tru Physics

    […] is the curl of the magnetic field, is the current density, are the permeability and permittivity of free space respectively, and is the rate of change of the electric […]

    Reply

Have something to add? Leave a comment!