An electric dipole is held in a uniform electric field $\overrightarrow{E}$. Show that the net force acting on it is zero.

An electric dipole is held in a uniform electric field $\overrightarrow{E}$. The dipole is aligned with its dipole moment $\overrightarrow{p}$ parallel to the field $\overrightarrow{E}$. Find the work done in turning the dipole till its dipole moment points in the direction opposite to $\overrightarrow{E}$.

An electric dipole is held in a uniform electric field $\overrightarrow{E}$. The dipole is aligned with its dipole moment $\overrightarrow{p}$ parallel to the field $\overrightarrow{E}$. Find the orientation of the dipole for which the torque acting on it becomes maximum.

Show that the electric field at the surface of a charged conductor is given by $\overrightarrow{E}=\frac{\sigma }{{\epsilon }_0}\widehat{n}$, where $\sigma$ is the surface charge density and n ̂ is a unit vector normal to the surface in the outward direction?

or

Derive an expression for the electric field at the surface of a charged conductor.