Draw electric field lines of positive charge.

Expression for an electric field is given by $\vec{E}=4000 x^2 \hat{i} \frac{V}{m}$. The electric flux through the cube of side $20\,cm$ when placed in electric field (as shown in the figure) is $.........V cm$.

A charge $Q\;\mu C$ is placed at the centre of a cube, the flux coming out from any surfaces will be

Explain the electric field lines and the magnitude of electric field.

Four closed surfaces and corresponding charge distributions are shown below

Let the respective electric fluxes through the surfaces be ${\phi _1},{\phi _2},{\phi _3}$ and ${\phi _4}$ . Then

A sphere of radius $R$ and charge $Q$ is placed inside a concentric imaginary sphere of radius $2R$. The flux associated with the imaginary sphere is