Figure shows a charge array known as an electric quadrupole. For a point on the axis of the quadrupole, obtain the dependence of potential on 'r' for `r/a gt gt 1`, and contrast your result with that due to an electric dipole, and an electric monopole (i.e, a single charge)

Explanation

For large r, quadrupole potential goes like `1//r^(3)`, dipole potential goes like `1//r^(2)` , monopole potential goes like 1/r.