Sources of Energy | Class 10 CBSE | Web Notes | Part 1: Introduction, What is a good source of energy?
In a physical or chemical process, total energy is conserved.
One form of energy can be converted to another. For example:
When a plate hits the ground, potential energy is converted to sound energy.
In a burning candle, chemical energy is converted to heat energy and light energy.
These energy forms cannot be reversed back to their previous forms.
When hot water is kept at room temperature, the heat energy is lost to the environment. This lost energy cannot be re-collected to heat the water again.
Dissipated usable energy cannot be used again.
WHAT IS A GOOD SOURCE OF ENERGY?
Various sources of energy are used for doing work.
Muscular energy is used to carry out physical work, electrical energy for running various appliances, and chemical energy for cooking food or running a vehicle, all of which come from some sources.
Various fuels for cooking include electricity, LPG, wood, coal, solar cookers, etc.
A good fuel is easily available, efficient, cheap, clean, and easy to use, producing no or minimal pollutants. For example, in homes, LPG and electricity are preferred as they are highly efficient, smokeless, easily available, and easy to use.
Selection of fuels also depends on the work to be done and the amount of energy needed.
Advantages of a good source of energy:
Does a large amount of work per unit volume or mass.
