Two-point charges +2 C and +6 C separated by distance ' r ' repel each other with a force of 18 N . If negative charge of 4 C is added to each of these charges, then the force experienced by them is

Step-by-step solution

The initial charges are q₁ = +2 C and q₂ = +6 C , separated by distance r . The initial repulsive force is F₁ = 18 N . Using Coulomb's Law, F₁ = k |q₁ q₂| r^2 = k 12 r^2 , giving 18 = k 12 r^2 . Adding -4 C to each charge yields q₁' = -2 C and q₂' = +2 C . The new force is F₂ = k |(-2)(2)| r^2 = k 4 r^2 . Taking the ratio of the forces, F₂ 18 = 4 12 = 1 3 , so F₂ = 18 3 = 6 N . The charges are opposite in sign, resulting in an attractive force.