In this topic, you study the different sources of electricity.
The different sources of electricity by which the electricity can be produced are known as the source Of electricity. There are a number of sources by which the electricity can be produced, these are as follows:
By friction: When two bodies or things are rubbed heat is produced, in the same way the static electricity can be produced by friction. When the glass rod is rubbed with silk or ebonite rod with cat skin in both the ways the electricity produced is Of static nature and is produced by friction. This electricity cannot be transmitted from one place to the another.
By chemical means: The electriéity can be produced by means of chemical action for example if two dissimilar rods say of Zn and Cu are put in dilute sulphuric acid the electricity will be produced. Whenever in a jar two dis-similar rods of zinc and copper are immersed some bubbles of the nascent hydrogen over the zinc rod is seen. The nascent hydrogen is very active and negatively charged, it gives away its charge to copper. If a galvanometer is connected between copper and zinc and rod it deflects. The electricity in the cell is caused by the chemical changes. In batteries this electrical energy is being stored in the shape of chemical energy, which can be used at any time, or in other words the battery can be said as the portable electricity. In this case the electricity flows form positive to negative.
By mechanical means: In this way the mechanical energy can be covered into electrical energy by means of generators. This type Of energy is the dynamic electricity. The principle is same as whenever a conductor links with the changing flux or cuts the magnetic lines of force, an e.m.f is produced in that conductor. This e.m.f. causes the current to flow through the conductor. The current flows from positive to negative.
In this way the produced current is of two types:
- Direct current.
- Alternating current.
The current in which the direction and value of the current does not change is known as direct Current. It is produced by D.C. generator. The current which changes its value and direction after a definite interval of time is called alternating current. This current is produced by the A.C. generator called alternator.
By means of heat: The electricity produced by the heat is called thermal electricity. When dis-similar metals are joint in the shape of bow and the junction is heated and the other is kept cold, the current flows from hot portion to cold portion. The Current produced by the heating is called the thermal electricity. This is Of very small quantity and .is having a limited field.
By means of lighting: When light falls on the dissimilar metals, the electricity is produced. Photoelectric cell is the example of this effect. This type of electricity is used in ratio and electronics circuits etc.
By means of solar cell: Electricity can be produced by means of solar cells. When light falls over them it is converted into electricity.