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  $O{P}^{\text{'}}=\left(\frac{y}{3}\right)$ . The force on Q  will be $n\times F$.

Find n