question_answer 13)

Suppose the spheres A and B in Q.1.12 have identical sizes. A third sphere of the same size but uncharged is brought in contact with the first, then brought in contact with the second, and finally removed from both. What is the new force of repulsion between A and B? 

Answer:

Charge on sphere A on contact with third sphere (say C) having no charge is given by                                                 When third sphere, now having, charge is brought in contact with sphere B, the charge left on sphere R given by,                                                  New Columb?s force                                 .