An electric field is given by $(6 \hat{i}+5 \hat{j}+3 \hat{k}) \ N / C$.

The electric flux through a surface area $30 \hat{\mathrm{i}}\; m^2$ lying in $YZ-$plane (in SI unit) is

A charge $q$ is located at the centre of a cube. The electric flux through any face is

A charge is kept at the central point $P$ of a cylindrical region. The two edges subtend a half-angle $\theta$ at $P$, as shown in the figure. When $\theta=30^{\circ}$, then the electric flux through the curved surface of the cylinder is $\Phi$ If $\theta=60^{\circ}$, then the electric flux through the curved surface becomes $\Phi / \sqrt{n}$, where the value of $n$ is. . . . . . .

A few electric field lines for a system of two charges $Q_1$ and $Q_2$ fixed at two  different points on the $x$ -axis are shown in the figure. These lines suggest that:-

How field lines depend on area or on solid angle made by area ?