Charges - q and + q located at A and B, respectively, constitute an electric dipole. Distance AB =2 a, O is the mid point of the dipole and OP is…

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