$A$ charge $Q$ is placed at a distance $a/2$ above the centre of the square surface of edge $a$ as shown in the figure. The electric flux through the square surface is

The black shapes in the figure below are closed surfaces. The electric field lines are shown by dashed arrows. For which case,the net flux through the surfaces is non-zero?

$A$ positive charge $q$ is placed at the centre of a neutral hollow cylindrical conducting shell with its cross-section as shown in the figure below. Which one of the following figures correctly indicates the induced charge distribution on the conductor? (Ignore edge effects)

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

If electric flux through a cubic Gaussian surface is $1.9 \times 10^5 \text{ Nm}^2 \text{C}^{-1}$,then the electric charge at its center is . . . . . . . (Edge length of cube = $9.0 \text{ cm}$).

$A$ circular plate sheet of radius $10 \,cm$ is placed in a uniform electric field of $2 \sqrt{3} \times 10^5 \,NC^{-1}$, making an angle of $60^{\circ}$ with the field. Find the electric flux through the sheet.