Two charges Q each are separated by distance 2 l.At what distance the force is maximum

Dear student,

We are assuming that you are asking about the force on a third charge being placed along the line of joining of the the two Q charges.

According to the Coulomb’s law, the force acting on a charge is inversely proportional to the distance between it and the charge exerting the force. So the force is maximum when the third charge is closest to the other two charges. Hence the force is maximum(approaching infinity) at two points- at when inifinitely close to either of the charge.