A positive point charge ($+Q$) is kept in the vicinity of an uncharged conducting plate. Sketch electric field lines originating from the point charge on to the surface of the plate.

Figure shows two large metal plates, $P_1$ and $P_2$ tightly held against each other and placed between two equal and unlike point charges perpendicular to the line joining them.

What will happen to the plates when they are released?

Figure shows two large metal plates, $P_1$ and $P_2$ tightly held against each other and placed between two equal and unlike point charges perpendicular to the line joining them.

Draw the pattern of the electric field lines for the system.

In the electric field shown in Figure the electric field lines on the left have twice the separation as that between those on the right. If the magnitude of the field at point $A$ is $40 {\mathrm{NC}}^{-1}$, calculate the force experienced by a proton placed at point $A$ Also find the magnitude of electric field at point $B$.

Consider the situation shown in Figure What are the signs of $q_1$ and $q_2$? If the lines are drawn in proportion to the charge, what is the ratio $\frac{{\mathrm{q}}_1}{{\mathrm{q}}_2}$?