CBSE Class 10 Answered

Energy can be harnessed from different sources - renewable or non renewable sources. Renewable sources of energy include water, solar, wind, biogas while non-renewable sources of energy include petroleum, coal, oil and gas. Water energy is harnessed by using turbines, which uses energy of flowing water to rotate its blades which then produces energy. Solar energy is harnessed using solar cells which uses semi-conductors to convert light energy into heat energy. Similarly, to harness wind energy, huge wind mills are used. Non-renewable sources of energy are generally combusted in the presence of air to convert its energy into heat energy.