Two identical, small metallic shpheres A and B are placed side by side on an insultaing smooth table as shown in the figure. If A is positively charged and held fixed with the table , discuss the motion of B.

Explanation

When A is charged positively, then negative and positive charges are induced on B as shown in Fig. (a). Then B will be attracted by A and comes into contact with A. When B is in contact with A, due to conduction, positive charge flows from A to B and B also becomes positively charged. [Fig. ]

Then A and B repel each other and B moves away from A (Fig. ).