How does the electric potential energy between two charged particles change if one particle's charge is increased by a factor of 2?

Magnitude of potential energy is increased by factor "2"

Explanation:

As we know that if two charge particles are placed at some distance "r" from each other then the electrostatic potential energy between two charge particles is given as

now we know that if the charge of one of the charge particle is increased to twice of initial charge then

now we can say from above two equations that

so on increase one of the charge to twice of initial value then the potential energy will become TWICE