Question

39. The electrostatic force between two charged spheres is 64 N. What will the magnitude of the force be if the size of each charge is doubled and the distance between the spheres is doubled?

Answer 1

force = constant* charge1*charge2/distance^2
charge 1, charge 2 are doubled, and distance doubled
2*2/2^2=4/4 = 1, so it remains same.