Name and describe some non- conventional sources of energy.
Non-conventional power sources are those power sources that have come into use recently due to the depleting conventional resources and growing awareness. Solar energy, wind energy, geothermal energy, nuclear power and tidal energy are examples of non- conventional power sources.
Solar energy is the heat and light energy captured from the sun. Solar cells help to convert this energy to electricity. Solar energy is used in solar heaters, solar cookers, solar dryers, etc.
Wind energy is the energy possessed by moving air (wind). Windmills are used to convert wind energy to electricity. Wind farms having clusters of windmills located in coastal regions and mountain passes.
Nuclear power is energy possessed by the nuclei of atoms of naturally occurring radioactive elements like uranium-, thorium, etc.
Geothermal energy is the heat energy obtained from the inside of the earth. The temperature inside the earth increases as we go deeper. This heat is used to produce electricity. It is accessed in the form of hot springs. Tidal energy is the energy generated from tides. It is harnessed by building dams at narrow openings of the sea. Biogas is a gaseous fuel obtained from the decomposition of organic waste like dead plant and animal material or animal dung and kitchen waste. It is an excellent fuel for cooking and lighting, and is environment-friendly.
Give Reason for Environmental aspects must be carefully looked into before building huge dams.
Pick the Correct Asnwer
(a) Which one of the following is NOT a characteristic of minerals?
(i) They are created by natural processes
(ii) They have a definite chemical composition
(iii) They are inexhaustible
(iv) Their distribution is uneven
(b) Which one of the following is NOT a producer of mica?
(i) Jharkhand (ii) Karnataka (iii) Rajasthan (iv) Andhra Pradesh
(c) Which one of the following is a leading producer of copper in the world?
(i) Bolivia (ii) Ghana (iii) Chile (iv) Zimbabwe
(d) Which one of the following practices will NOT conserve LPG in your kitchen?
(i) Soaking the dal for some time before cooking it
(ii) Cooking food in a pressure cooker
(iii) Keeping the vegetables chopped before lighting the gas for cooking
(iv) Cooking food in an open pan kept on low flame
Which sources of energy would you suggest for (a) rural areas (b) coastal areas (c) Arid Regions?
Answer the following questions.
(i) Name any three common minerals used by you every day.
(ii) What is an ore? Where are the ores of metallic minerals generally located?
(iii) Name two regions rich in natural gas resources.
(iv) Which sources of energy would you suggest for
(a) rural areas (b) coastal areas (c) arid regions
(v) Give five ways in which you can save energy at home.
Give reasons.
(i) Environmental aspects must be carefully looked into before building huge dams.
(ii) Most industries are concentrated around coal mines.
(iii) Petroleum is referred to as "black gold".
(iv) Quarrying can become a major environmental concern.
Fill in the blank spaces given to complete each sentence.
(i) Metallic minerals are classified into …………….. and ………….
(ii) Gold and silver are …………. minerals.
(iii) Minerals can be extracted by …………. ,…………. or …………
(iv) Deep bores dug to reach mineral deposits are called …………
(v) Metallic minerals are generally found in ……….. and…………..rock formations.
(vi) The mineral deposits in North America are located in three zones: …………… the Appalachian region and the mountain ranges of the West.
(vii) ……………. is the largest producer of bauxite in the world.
(viii) ………….. is the most abundantly available fossil fuel.
(ix) Petroleum is drilled from ………
(x) Bhakra Nangal is an important …………….. station in India.
(xi) ……………. and……… are radioactive metals.