Draw the electric field lines for a negative point charge.

$A$ charged particle $q$ is placed at the centre $O$ of a cube of side length $L$ $(A, B, C, D, E, F, G, H)$. Another identical charge $q$ is placed at a distance $L$ from $O$, outside the cube, as shown in the figure. The electric flux through the face $BGFC$ is

$A$ point charge of $2.0 \; \mu C$ is at the centre of a cubic Gaussian surface $9.0 \; cm$ on edge. What is the net electric flux through the surface?

If the radius of the spherical Gaussian surface is increased, then the electric flux due to a point charge enclosed by the surface

$A$ hemispherical surface of radius $a$ is placed in a uniform electric field $E$ such that the flat surface makes an angle of $\pi /4$ with the vertical. There is no charge inside the hemisphere. The electric flux passing through the curved surface of the hemisphere is:

$A$ 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