Calculate the potential at P due to the charge configuration shown in the figure. If r>>a, then how will you modify the result?
The potential at P due to the given charge configuration is the sum of the potentials due to charges -q, +q and +q. These charges are at distances r + a, r and r - a respectively from the point P.
or
If r>> a, then r2- a2= r2
When r>>a, the potential at P is simply the potential of a dipole and an isolated charge at distance r.
