An electric dipole is a pair of equal and opposite charges, separated by a small fixed distance between them. The dipole is free to move. What is the action on it, when it is placed in a uniform electric field.

Two small identical electrical dipoles $AB$ and $CD$, each of dipole moment '$p$' are kept at an angle of $120°$ as shown in Fig. What is the resultant dipole moment of this combination? If this  system is subjected to electric field $\left(\overrightarrow{E}\right)$ directed along $+X$ direction, what will be the magnitude and direction of the torque acting on this?

A thin metallic spherical shell of radius $R$ carries a charge $Q$ on its surface. A point charge $\frac{Q}{2}$ is placed at its centre $C$ and another charge $+2Q$ is placed outside the shell at a distance $X$ from the centre as shown in Fig.

Find the force on the charge at the centre of shell and at the point $A$.