Find out potential energy of the two point charge system having charges `q_(1)` and `q_(2)` separated by distance r.

Explanation

Let both the charges be placed at a very large separation initially.
Let `W_(1)` = work done in bringing charge `q_(1)` in absence of `q_(2) = q(V_(f) - V_(i)) = 0 W_(2)` = work done in bringing charge `q_(2)` in presence of
`q_(1) = q(V_(f) - V_(i)) = q_(1)(Kq_(2)//r - 0)`
`PE = W_(1) + W_(2) = 0 + Kq_(1)q_(2)//r = Kq_(1)q_(2)//r`