Consider the charges and the Gaussian surface shown in the figure. When calculating the electric flux through the spherical surface,the electric field is due to which of the following?

$A$ metallic sphere of radius $R$ carrying a charge $q$ is kept at a certain distance from another metallic sphere of radius $R/4$ carrying a charge $Q$. What is the electric flux at any point inside the metallic sphere of radius $R$ due to the sphere of radius $R/4$?

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 $TRUE$?

$A$ cylinder of radius $R$ and length $L$ is placed in a uniform electric field $E$ parallel to the cylinder axis. The total flux for the surface of the cylinder is given by

$A$ line charge of length $\frac{a}{2}$ is kept at the center of an edge $BC$ of a cube $ABCDEFGH$ having edge length $a$ as shown in the figure. If the linear charge density is $\lambda \; C/m$, then the total electric flux through all the faces of the cube will be . . . . . . . (Take $\varepsilon_0$ as the free space permittivity)

$A$ charge $q$ is placed at the centre of the open end of a cylindrical vessel. The flux of the electric field through the surface of the vessel is: