When an ebonite rod is rubbed with wool, the process of charging occurs through a combination of friction and electron transfer, not conduction. Here's a step-by-step explanation of what happens:
Triboelectric Effect: The phenomenon that causes the charging of materials through friction is called the triboelectric effect. It occurs when two dissimilar materials come into contact and then separate, causing a transfer of electrons between them.
Electron Transfer: Ebonite and wool are two materials with different electron affinities, which means they have a tendency to either gain or lose electrons when they come into contact with each other. When the ebonite rod is rubbed against the wool, some of the electrons from one material are transferred to the other.
Charging by Electron Transfer: As the ebonite rod is rubbed against the wool, electrons from the ebonite are transferred to the wool. This leaves the ebonite with a net positive charge since it has lost some of its negatively charged electrons. Conversely, the wool gains these extra electrons and becomes negatively charged.
Opposite Charges: The ebonite rod and wool acquire opposite charges during this process. The ebonite becomes positively charged, and the wool becomes negatively charged.
It's essential to understand that this charging process happens through the transfer of electrons and not through conduction. Conduction involves the flow of charges (usually electrons) through a conductive material when there is an electrical potential difference. However, in the case of the ebonite rod and wool, the charges do not flow through them; instead, the charges are statically accumulated on the surfaces of the materials, making them oppositely charged. This static charge buildup is what causes them to attract or repel each other and other charged objects.