The electric field intensity at a point near and outside the surface of a charged conductor of any shape is $E_1$. The electric field intensity due to uniformly charged infinite thin plane sheet is $E_2$. The relation between $E_1$and $E_2$ is

The electric field due to a uniformly charged sphere of radius $R$ as a function of the distance from its centre is represented graphically by

Three identical small dipoles are arranged as shown in the figure. What will be the net electric field at $P$? ($k=\frac{1}{4\pi {\epsilon }_0}$)