Question

What is energy in electric field?

Answer 1

1. Energy is the capacity to do work.
2. The electric field is a vector field that can be associated with each point in space.
3. The energy of electric field results from excitation of the space permeated by an electric field.
4. The potential energy in an electric field:
   $\mathrm{U}=\frac{{\mathrm{kq}}_1{\mathrm{q}}_2}{\mathrm{r}}$
   where $\mathrm{U}$is the potential energy of the electric field, $\mathrm{k}$ is the constant, ${\mathrm{q}}_1\mathrm{and}{\mathrm{q}}_2$ are the charges, $\mathrm{r}$ is the distance between the charges.
5. The energy stored in an electric field. For the electric field, the energy density is ${\eta }_E=\frac{energy}{volume}=\frac{1}{2}\epsilon E^2$
   where $\mathrm{E}$is the electric field vector, $\mathrm{\epsilon }$ is the permittivity of the medium.
   This formula is used to calculate the electric field of the capacitor.