Electric charge is the feature of the sub atomic particles which determines the electromagnetic interaction between them.
As we all know the positive and negative charges on an object are equal. Due to equal balancing of charges, large amount of charge on an object is almost hidden. Those objects on which positive and negative charges are equal are said to be electrically neutral. In other words we can also say that, ‘there is no net charge present on the object.
Basic types of charges
Charges are of two types. It is the basic property of charge that it exists only in two forms. One is positive charge and other is negative charge. Let us take an example to clear the types of charges.
Take a glass rod and rub it with a silk cloth. Hang it in air with the help of thread. Now take another glass rod. Repeat the same process of rubbing it. Bring both glass rods near to each other. The rods will repel each other.
Similarly take two ebonite rods. Rub both the rods with fur. Bring both rods nearer to each other. Repulsion will take place.
Now in case third, take one glass rod and rub it with silk cloth. On the other hand take an ebonite rod and rub it with fur. Then bring both rods closer to one another. You will observe that attraction will take place between the rods. It is cleared from the experiment that the charge present on glass rod is different from that of ebonite rod. So it is founded beyond doubt that there are two kinds of charges. So formally the charge present on the glass rod is taken as positive and the charge present on the ebonite rod is taken as negative. So it is proved that like charges repel each other and unlike charges attracts each other.
Note: It is not true that attraction can be seen only between the bodies having opposite charges. Two bodies one charged and other uncharged, one uncharged and other electrically neutral can also show attraction.
Types of charges on different objects:
Positive Charge: Glass rod, Fur, Woolen coat, woolen carpet, Nylon, Dry hair.
Negative charge: Silk cloth, Ebonite rod, plastic seat, Rubber shoes, Cloth, comb.
