$C_1$ and $C_2$ are two hollow concentric cubes enclosing charges $2Q$ and $3Q$ respectively as shown in the figure. The ratio of electric flux passing through $C_1$ and $C_2$ is:

In the figure,a point charge $+Q_1$ is at the centre of an imaginary spherical surface and another point charge $+Q_2$ is outside it. Point $P$ is on the surface of the sphere. Let $\Phi _s$ be the net electric flux through the sphere and $\vec E_p$ be the electric field at point $P$ on the sphere. Which of the following statements is $TRUE$?

The number of lines of force originating from a point charge of $2 \times 8.85 \times 10^{-9} \text{ C}$ in a medium of dielectric constant $10$ is $(\epsilon_0 = 8.85 \times 10^{-12} \text{ SI unit})$.

$A$ charge $q$ is placed inside a hollow cylinder. The electric flux associated with the curved surface $B$ is $\phi$. The flux associated with a plane surface (either $A$ or $C$) will be:

How do electric field lines depend on the area or the solid angle subtended by the area?

The figure shows the electric field lines around three point charges $A, B$,and $C$.
$(a)$ Which charges are positive?
$(b)$ Which charge has the largest magnitude? Why?
$(c)$ In which region or regions of the picture could the electric field be zero? Justify your answer.
$(i)$ Near $A$ $(ii)$ Near $B$ $(iii)$ Near $C$ $(iv)$ Nowhere