Question

State Gauss's theorem and state its any 'two' applications.

Answer 1

Gauss's theorem: It states that electric flux ${\varphi }_E$ through any closed surface is equal to $\frac{1}{{\epsilon }_0}$ times the net charge '$q$' enclosed by the surface.

${\varphi }_{\epsilon }=\oint E.dA=\frac{q}{{\epsilon }_0}$

Two applications:

$\left(1\right)$ For finding out electric field due to different shapes i.e., infinite line of charge.
$\left(2\right)$ For finding out electric field due to uniformly charged infinite plane sheet.