$A$ point charge causes an electric flux of $-2 \times 10^4 \ Nm^2 C^{-1}$ to pass through a spherical Gaussian surface of $8.0 \ cm$ radius,centred on the charge. The value of the point charge is: (Given $\epsilon_0 = 8.85 \times 10^{-12} \ C^2 N^{-1} m^{-2}$)

The figure shows two situations in which a Gaussian cube sits in an electric field. The arrows and values indicate the directions and magnitudes (in $N-m^2/C$) of the electric flux through the faces of the cube. What is the net charge (in the two situations) inside the cube?

Consider a region in free space bounded by the surfaces of an imaginary cube having sides of length $a$ as shown in the figure. $A$ charge $+Q$ is placed at the centre $O$ of the cube. $P$ is a point outside the cube such that the line $OP$ perpendicularly intersects the surface $ABCD$ at $R$, and $OR = RP = a/2$. $A$ charge $+Q$ is also placed at point $P$. What is the total electric flux through the five faces of the cube other than $ABCD$?

If electric flux is coming out of a Gaussian surface,what is associated with the surface?

Write the $SI$ unit of electric flux.

What is the net flux of the uniform electric field of $E = 3 \times 10^{3} \hat{i} \; N/C$ through a cube of side $20 \; cm$ oriented so that its faces are parallel to the coordinate planes?