Question

What is the electric field due to a uniformly charged thin insulating infinite plane sheet?

Options

• \[E = \frac{\sigma}{\varepsilon_0}\]

• \[E = \frac{\sigma}{4\pi\varepsilon_0 r^2}\]

• \[E = \frac{\sigma A}{2\varepsilon_0}\]

• \[E = \frac{\sigma}{2\varepsilon_0}\]

Answer 1

For the insulating sheet, flux exits through both flat faces, giving \[2EA = \sigma A/\varepsilon_0\]. Cancelling \[A\) gives \[E = \sigma/(2\varepsilon_0)\].