Two infinitely large charged planes having uniform surface charge density $+\mathrm{\sigma } \mathrm{and} -\mathrm{\sigma }$ are placed along x-y plane and y-z plane, respectively, as shown in the figure. Then the nature of electric lines of forces in x-z plane is given by

The electric field intensity due to each uniformly charged infinite plane is uniform. The electric field intensity at points A, B, C andD due to plane 1, plane 2 and both planes are given by E₁, E₂ and E as shown in figure l . Hence, the electric lines of forces are as given in figure 2.