Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

What is the correct formula for electric permittivity?

Image here

share|cite|improve this question
up vote 0 down vote accepted

If you are looking for a formula for $\epsilon_0$ (vacuum permittivity), you will not find it, because $\epsilon_0$ is a constant. $$\epsilon_0=8.854187817\times 10^{−12} \frac{F}{m}$$ In other hand, permitivity $\epsilon$ is defined as follows $$\epsilon=(1+\chi_e)\epsilon_0$$ Where $\chi_e$ is called the electric susceptibility, and is defined with $$\mathbf{P}=\chi_{e}\epsilon_{0}\mathbf{E}$$ Where $\mathbf{P}$ is the polarization vector.

share|cite|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.