Figure below shows a metal rod AB placed on an insulating stand. In Fig.(a), a negatively charged ebonite rod C is touched with the metal rod AB, while in Fig.(b), the negatively charged ebonite rod C is held near the rod AB. State the kind of charges at the ends A and B of the rod, in each case.

In Fig.(a), rod AB gets charged by conduction. There is negative charge at both ends A and B of the metal rod AB.

In Fig.(b), rod AB gets charged by induction. It's end A which is near to the rod C becomes positively charged and the end B which is far from the rod C becomes negatively charged.