Charges $-q$ and $+q$ located at $A$ and $B$, respectively, constitute an electric dipole. Distance $AB = 2a$, $O$ is the mid point of the dipole and $OP$ is perpendicular to$AB$. A charge$Q$ is placed at $P$ where $OP = y$ and $y >> 2a$. The charge $Q$ experiences an electrostatic force $F$. If $Q$ is now moved along the equatorial line to $P\text{'}$ such that the $OP\text{'}=\left(\frac{y}{3}\right)$, force on $Q$ will be close to $\left(\frac{y}{3}>>2a\right)$