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Published by: Nuru

Published date: 06 Jul 2021

Energy in Class 10 Science


Energy is defined as the ability or capacity to perform work.

On the basis of their form, they are used. There are two types of energy sources:

The primary sources are:

These are the sources that are being used in their natural form. Wood, coal, crude oil, natural gas, solar energy.

The secondary sources are:

They are derived from secondary sources. Coal gas, biogas, kerosene, petrol, diesel, charcoal are examples of secondary sources.

On the basis of replacing period can be classified into two types:

Non-Renewable sources: Non-renewable sources are found to be accumulated in nature over a very long time and cannot be quickly replaced when exhausted at their origin place. For example Coal, natural gas, petroleum, nuclear, etc.

Renewable sources: The sources that can be replaced if they are exhausted at their origin place are called renewable sources. They are being produced continuously in nature and cannot be exhausted. They are:

  1. Hydropower
  2. Biofuel
  3. Tidal
  4. Wind
  5. Geothermal
  6. Solar

Sun as the ultimate source of energy

The sun is the ultimate source of almost all kinds of energy on earth, either directly or indirectly. Fossil fuels (coal, oil, and gas) are the transformed forms of plants (and animals) which once lived on the earth and grew to capture the energy of the sun. Biomass is a product of photosynthesis where the sun has a major role. Hydroelectricity depends upon the water cycle which again is dependent on solar radiation. Similarly, wind, tidal power, wave power all, in some way or other, and depend on the sun.

Fuel crisis:

The future scarcity of energy sources on the earth due to overpopulation, urbanization, and industrialization is called the fuel crisis. Since the non-renewable resources will not last long and cannot be regained, the world is going to face the problem of crisis in the near future. The only solution to the crisis is its saving. It can be done in the following ways:

  • By reducing the use of renewable sources.
  • By developing the alternative source.
  • By controlling the population growth.

The alternative source:

The source of energy, which can be used instead of non-renewable sources is called an alternative source. E.g. nuclear energy