This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
From coulomb's equation, derive electric field. From that derive electric potential.
From that derive potential energy.

q1 is at A and q2 is at B and AB = r.
force on q2 by q1 =  F = Z * q1 * q2 / r^2
             Z =  1 / 4pie epsilon
electric field at B due to q1  = F / q2  = E =  Z q1 / r^2
Electric potential at B due to q1 = Integral E dr    ,  r varies from infinity to AB
               = V at B =  - Z q1 / r
Potential Energy at distance AB of both charges : q2 * V at B
Potential Energy in bringing q2 from infinity to B =
         q2 ( potential at B - potential at infinity)  = - Z q1 Q2 / r
                    as potential and P E at infinity are zero.

1 5 1