The electric force between two charged particles becomes weaker with increasing distance. Suppose instead that the electric force were independent of distance. In this case, would a charged comb still cause a neutral insulator to become polarized as in Fig. 21.8? Why or why not? Would the neutral insulator still be attracted to the comb? Again, why or why not?

Fig.21.8

Electrons in each molecule of the neutral insulator shift away from the comb. This time, electrons in the molecules shift toward the comb . Positively charged comb `Negatively charged comb As a result, the (+) charges in each molecule are closer to the comb than are the () charges and so feel a stronger force from the comb. Therefore the net force is attractive. so the (-) charges in each molecule are closer to the comb, and feel a stronger force from it, than the (+) charges. Again, the net force is attractive.