Question

sources of energy class 10 important Points .

Answer 1

Renewable energy sources include biomass, geothermal energy, hydropower, solar energy, and wind energy. They are called renewable energy sources because they are naturally replenished regularly. Day after day, the sun shines, the wind blows, and rivers flow.

Answer 2

1.Energy comes in different forms and one form can be converted into another.
2 A source of energy is one which provide adequate amount of energy in a convenient form over a long period of time.

Need of energy

→ For making food
→ For lightning
→ For transport
→ For running machines
→ For industrial activities and agricultural work

Qualities of a Good Source of Energy

(i) Which would do a large amount of work per unit mass.
(ii) Cheap and easily available.
(iii) Easy to store and transport.
(iv) Safe to handle and use.
(v) Does not cause environmental pollution.

• Fuels: The materials which are burnt to produce heat energy are known as fuels.
Example: wood, coal, LPG, kerosene.
High calorific value (give more heat per unit mass).
→ Burn without giving out any smoke or harmful gases.
→ Proper ignition temperature.
→ Cheap and easily available.
→ Easy to handle, safe to transport