 |
| Charging by Friction |
|
| Keeping in mind the structure of the atom, we can easily explain charging by rubbing. When glass rod is rubbed with silk, some of the electrons from the atoms on glass are transferred to silk. Because there is a deficiency of electrons in the glass, it becomes positively charged. On the other hand, as the silk has acquired additional electrons it becomes negatively charged. |
| |
| Similarly, when an ebonite rod is rubbed against fur, some electrons are transferred from fur to the ebonite rod. Thus the ebonite acquires a negative charge and the fur acquires an equal amount of positive charge. |
| |
| You should note that charging by rubbing does not create charges. Rubbing simply causes transfer of electrons from one material to the other. When a positive charge is produced on one material an equal amount of negative charge is produced on the other. The net charge on the two is again zero. In fact, we do not produce any charge but we separate the two kinds of charges when we rub a rod. |
| |
| The SI unit of charge is coulomb (C). The charge on an electron is known to be |
| |
| e = -1.6 x 10-19
C. This is the smallest value of charge which exists in nature. The charge
on a proton is equal to
+ 1.6 x 10-19 C. |
| |
| If 'n' number of electrons are transferred from one body to another by rubbing, then the charge 'Q' acquired by each body, in magnitude would be Q = ne. |
| |
