If q1q2 > 0, potential
energy is positive This is as expected, since for like charges (q1q2 > 0),
electrostatic force is repulsive and a positive amount of work is needed to
be done against this force to bring the charges from infinity to a finite
distance apart For unlike charges (q1 q2 < 0), the electrostatic force is
attractive In that case, a positive amount of work is needed against this
force to take the charges from the given location to infinity