An electric dipole is placed in uniform electric field in an unstable equilibrium position. Now the dipole is rotated in this field. The graph which best represents variation of its potential energy is given by,

The dipole moment of the given charge distribution is,

Six charges are placed at the vertices of a regular hexagon as shown in the figure.

The electric field on the line passing through point $O$ and perpendicular to the plane of the figure at a distance of $x(>>a)$ from $O$ is,

Figure shows electric field lines in which an electric dipole $p$ is placed as shown. Which of the following statements is correct?