Electricity is an important source of energy in the modern times. Electricity 🔌 is used in our homes, in industry and in transport. For example, electricity is used in our homes for lighting, operating fans and heating purpose. In industry, electricity is used to run various types of machines, and in transport sector electricity is used to pull electric train 🚂.
In this article, we will discuss electric potential, electric current, electric power and the heating effect of electric ⚡ current. In order to understand electricity, we should first know something about the electric charges. These are discussed below.
If we bring a plastic comb near some very tiny pieces of paper 🗞️, it will not have any effect on them. If however, the comb is first rubbed with dry hair and then brought near the tiny pieces of paper, we find that the camb now attracts the pieces of paper 🗞️ towards itself. These observation are explained by saying that initially the comb is electrically neutral so it has no effect on the tiny pieces of paper. When the comb is rubbed with dry hair, then it gets electric ⚡ charge. This electric charged comb exerts an electric force on the tiny pieces of paper and attracts them. Similarly, a glass rod rubbed with silk cloth, and an ebonite rod rubbed with woollen cloth also acquire the ability to attract small pieces of paper and are said to have electric charge.
Types of Electric Charges
It has been found by experiment that there are two types of electric charges:
- Positive charges
- Negative charges
By convention, the charge acquired by a glass rod (rubbed with a silk cloth) is called positive charge and the charge acquired by an ebonite rod (rubbed with a woollen cloth) is called negative charge.
An important property of electric charges is that:
- Opposite Charges (or Unlike charges) attract each other. For example, a positive charge attracts a negative charge.
- Similar charges (or Like charges) repel each other. For example, a positive repels a positive charge; and a negative charge repels a negative charge.
