Two point charges of charge `q_(1)` and `q_(2)` (both of same sign) and each of mass m are placed such that gravitational attraction between them balances the electrostatic replusion. Are they in stable equilibrium ? If not then what is the nature of equilibrium ?

Explanation

In given example :
`(Kq_(1)q_(2))/(r^(2)) = (Gm^(2))/(r^(2))`
We can see that irrespective of distance between them charges will remain in equilibrium. If now distance is increased or decreased then there is no effect in their equilibrium. Therefore it is a neutral equilibrium.