# Electric Flux is zero

When is the Electric Flux zero through a closed surface? I know that if number of field lines entering is equal to leaving then it is true. Which I think is always true for a closed surface. So can there be any situation in which an isolated surface has 0 flux?

• Gauss's law states that the flux through a closed surface is proportional to the charge contained within the surface... – lemon Apr 23 '16 at 13:25
• So What ? Will that answer my question – Kumar Sambhav Apr 23 '16 at 13:37
• Yes... To put it even more simply: the flux through a closed surface is equal to the charge contained within it (in the right units). So under what circumstance will the flux be zero? – lemon Apr 23 '16 at 14:02

Electric flux through a closed surface $\rm S$ is $$\Phi= \int_{\mathrm S} \,\mathbf E\cdot \mathbf n\,\mathrm d^2 \mathbf r\;.$$
From $(1)\,,$ it can be concluded that when $Q_\textrm{int}= 0\,$ the electric flux is zero.