Physics

# Explain Principle of Conservation of Energy

Energy can be transformed form one form to another or more forms. The total energy of the universe is constant and unchangeable.

Transformation of energy: We have mentioned earlier about different forms of energy. All of them are related to one another. In other words, it is possible to transform one form of energy into another. This is known as the transformation of energy. In fact, almost every natural phenomenon can be considered as a transformation of energy. Several examples of energy transformation are described below.

1. Transformation of mechanical Energy: Rubbing of hands produces heat. In this case, mechanical energy is converted into heat energy. If we low air in an empty pen cap, mechanical energy is converted into sound energy. When water is on a hill or a mountain, potential energy is stored in it. When this water flows down through a spring or river then the potential energy is transformed into kinetic energy. This flow of water can rotate a wheel to produce electricity. In this way mechanical energy can be transformed into electrical energy.
2. Transformation of heat Energy: In steam engine heat is used to produce steam for driving train etc. Here heat energy is converted into mechanical energy. Heat energy is converted into light energy by conducting electric current through the filament of a bulb. If the junction of two different metallic substances is heated, the heat energy is converted into electric energy.
3. Transformation of light energy: If we touch the chimney of a lantern we feel it be hot. Here the light energy is converted into heat energy. The action of light on a photovoltaic cell converts light energy into electric energy. Due to the action of light on a photographic film light energy is transformed into chemical energy.
4. Transformation of chemical energy: Food and fuel, such as oil, gas, coal and wood are the sources of chemical energy. The energy of food is released in our body by chemical reaction and we can work when this energy is transformed into other forms of energy. When fuel is burnt in an engine or boiler, the transformation of energy takes place. In an electric cell, chemical energy is transformed into electrical energy. In the filament of an electric bulb, electrical energy is transformed into light and heat energy.
5. Transformation of electrical energy: In electric motor electric energy is transformed into mechanical energy. In instruments like heater, electric iron etc. electric energy is converted into heat energy. In electric bulbs, electric energy is converted into light energy. The receiver of a telephone or radio converts electrical energy into sound energy. In a storage cell electric energy is converted into chemical energy. In electromagnets, electric energy is converted into magnetic energy.
6. Transformation of Nuclear energy: In nuclear submarine, nuclear energy is transformed into mechanical energy. The devastating action of the atom bomb is nothing but the transformation of nuclear energy. Nowadays, the transformation of nuclear energy into other forms of energy especially electrical energy in a nuclear reactor mostly satisfies the demand of energy.