Gaussian Units: Electric Field

[soupdejour]

I am stuck with Gaussian units. If the field in vacuum is

$$E = \frac{Q}{r^2}$$

Is the field in a dielectric

$$E = \frac{Q}{\epsilon_r r^2}$$

, or is it unchanged?

 

[Born2bwire]

The latter is the correct equation. In gaussian units, free-space epsilon is unity, this is why I prefer MKS units since all the unities in natural units sometimes hide these kind of relationships.

 

[astrokreng]

In Gaussian units, the electric field is measured in units of statvolt per centimeter (statV/cm). In vacuum, the electric field is given by E = Q/r^2, where Q is the charge and r is the distance from the charge. However, in a dielectric material, the electric field is affected by the presence of the material's permittivity (ε_r). This means that the electric field in a dielectric is given by E = Q/(ε_r r^2), where ε_r is the material's permittivity. Therefore, the field in a dielectric is not unchanged and is dependent on the material's permittivity. It is important to use the correct units and equations when working with Gaussian units to accurately describe and measure electric fields.