Two identical conducting balls having unequal positive charges q₁ and q₂ are separated by a distance r . If they are made to touch each other and then separated to the same distance, the force between them will be

Step-by-step solution

Initial force: F₁ = k q₁ q₂ r^2 After touching, each ball gets charge q' = q₁+q₂ 2 New force: F₂ = k ( q₁+q₂ 2 )^2 r^2 Comparing: since q₁ q₂ , (q₁-q₂)^2 > 0 (q₁+q₂)^2 > 4q₁q₂ ( q₁+q₂ 2 )^2 > q₁q₂ F₂ > F₁ , the force is more than before.