Question

Two identical small conducting spheres having unequal positive charges $q_1$ and $q_2$ are separated by a distance r. If they are now made to touch each other and then separated again to the same distance, the electrostatic force between them in this case will be :

• A. less than before
• B. same as before
• C. more than before
• D. zero

Answer 1

The correct option is C more than before

Before touch the electrostatic force between them is $F=\frac{k{q}_1{q}_2}{r^2}$

When they are touched, the charge will flow still they have same potential. So the average charge on each sphere is $q_a=\frac{q_1+q_2}{2}$

Thus, $q_a>q_1$ and $q_a>q_2$ So, after touch the force between them will be more than before.