Page 67 - Science Class 08

so many methods which can be used to save v Use CFLs and tube light which consume
energy. Reuse and recycling can also be used to less energy.
save energy. v Food should be cooked in pressure cooker.

PREVENTING AN ENERGY CRISIS v Smokeless chulha should be used in which

You know about the importance of energy. You kerosene, coal or wood is used for
can imagine what would happened if there is cooking.
an unprecedented crisis of energy. It is, v Pulses and other such items should be
therefore, necessary for all of us to know the soaked for some me before cooking to
ways through which we can prevent any kind of reduce cooking me.
energy crisis.
v Keeping vessels covered while cooking
The most effec ve step that we can take to also reduces the cooking me.

prevent energy crisis to judicious use of energy.
Judicious use of energy include two things as:

v Not was ng energy : Switch off the
1. What is natural gas?
electrical appliances which are not in use.
2. How is natural gas obtained?
Reduce the flame while cooking and once
the water starts boiling, saves fuel. 3. Write the places of occurrence of natural
Use air condi oners, air coolers, room gas in India.

heater, geysers, etc. only when needed. 4. Why is the energy requirement
v Using suitable methods to save energy : increasing day-by-day?
People should use public transport instead 5. Why should we reduce our dependency
of private transport. For short distances from the fossil fuels?
they should use bicycle. 6. How can you save energy?

Fuel : Substance burnt to produce heat at a reasonable cost
Calorific value : Amount of heat liberated when one gram of the fuel is completely
burnt in sufficient supply of oxygen

Ignition temperature : Minium temperature required to burn a substance
Exhaustible sources
of energy : Sources of energy which can be used only once

Inexhaustible
sources of energy : Sources of energy which can be used again and again like wind,
solar energy, etc.
Fossil fuels : Fuels which are made up of the remains of dead animals and plants.

Petroleum : Natural liquid fuel made of thousands of hydrocarbons and
compounds of oxygen, nitrogen and sulphur

Science-8 67