What is the net flux of the uniform electric field of $E =3 \times 10^{3} i\; N / C $ through a cube of side $20\; cm$ oriented so that its faces are parallel to the coordinate planes?
All the faces of a cube are parallel to the coordinate axes. Therefore, the number of field lines entering the cube is equal to the number of field lines piercing out of the cube. As a result, net flux through the cube is zero.
How does the electric field lines depend on area ?
Consider an electric field $\vec{E}=E_0 \hat{x}$, where $E_0$ is a constant. The flux through the shaded area (as shown in the figure) due to this field is
An electric field converges at the origin whose magnitude is given by the expression $E = 100\,r\,Nt/Coul$, where $r$ is the distance measured from the origin.
Shown below is a distribution of charges. The flux of electric field due to these charges through the surface $S$ is
The black shapes in the figure below are closed surfaces. The electric field lines are in red. For which case, the net flux through the surfaces is non-zero?