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 $+q$ is placed somewhere inside the cavity of a thick conducting spherical shell of inner radius $R_1$ and outer radius $R_2$. A charge $+Q$ is placed at a distance $r > R_2$ from the centre of the shell. Then the electric field in the hollow cavity

A metallic shell has a point charge ‘$q$’ kept inside its cavity. Which one of the following diagrams correctly represents the electric lines of forces

A charge $Q$ is enclosed by a Gaussian spherical surface of radius $R$. If the radius is doubled, then the outward electric flux will

A metallic solid sphere is placed in a uniform electric field. The lines of force follow the path(s) shown in figure as

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