If one of two interacting charges is doubled, the force between the charges will double.
Explanation:
The force between two charges is given by Coulomb's law
[tex] F=\frac{k q1 q2}{r^{2}} [/tex]
K=constant= 9 x 10⁹ N m²/C²
q1= charge on first particle
q2= charge on second particle
r= distance between the two charges
Now if the first charge is doubled,
we get [tex] F'=\frac{k (2q1) q2}{r^{2}} [/tex]
F'= 2 F
Thus the force gets doubled.