5.3 ADDITIONAL QUESTIONS :
Answer the following in one sentences :
1. What are placer deposits ?
Ans: The minerals that occur as alluvial deposits are called placer deposits .
2. What is ore ?
Ans: Ore is an accumulation of any mineral mixed with other elements .
3. Give one difference between veins and lodes .
Ans: The smaller occurrences of minerals are called veins and larger ones are called lodes .
4. What is a mineral ?
Ans: Mineral is a homogenous , naturally occurring substance with a definable internal structure .
5. Which minerals are found in placer deposits ?
Ans: Minerals like gold , silver , tin and platinum which are not corroded by water are found in placer deposits .
6. Why are the most of the oceanic minerals not economically significant ?
Ans: Oceanic minerals are not economically significant because most of the mare widely diffused .
7. What is the importance of iron ore ?
Ans: Iron ore is the basic mineral and the backbone of the industrial development .
8. What are the two types iron ore found in India ?
Ans: Magnetic and Hematite are the two types of iron ore found in India .
9. Why is using dung cakes being discouraged ?
Ans: Dung cakes consumes most valuable manure which could be used in agriculture .
10. How is coal formed ?
Ans: Coal is formed due to compression of plant material over millions of years .
11. What is lignite ?
Ans: Lignite is a low grade brown coal , which is soft with high moisture content .
12. What are the uses of natural gas ?
Ans: Natural gas is used as a source of energy and raw material in petrochemical industry .
13. Why is Compressed Natural Gas (CNG) gaining popularity in the country ?
Ans: Compressed Natural Gas (CNG) is pollution free and also less expensive as compared to petroleum .
14. How is nuclear or atomic energy obtained ?
Ans: Nuclear or atomic energy is obtained by altering the structure of atoms .
15. Why is biogas superior in comparison to kerosene , dung cakes and charcoal ?
Ans: Bio gas has higher thermal efficiency in comparison to kerosene , dung cake and charcoal .
Answer the following questions in two to three sentences :
1. Why is mica one of the most used mineral in electric and electronic industries ?
Ans:
i) Due to its excellent electric strength and low power loss factor .
ii) Due to its insulating properties and resistance to high voltage .
2. Why is it necessary to conserve the mineral resources ?
Ans: It is necessary to conserve the mineral resource because :
i) Industry and agriculture depend on mineral deposits and the substances manufactured for them .
ii) The geological processes of mineral formation are very slow , mineral resources are finite and non-renewable .
3. How can we use our mineral resources in a planned and sustainable manner ?
Ans:
i) Improved technologies need to be constantly evolved to allow use of low grade ores at low costs .
ii) Recycling of metals , using scrap metals and other substitutes are steps in conserving our mineral resources for the future .
4. What is the importance (uses) of petroleum ?
Ans: The importance of petroleum are :
i) Petroleum provides fuel for heat and lighting .
ii) It provides lubricants for machinery and raw materials for number of manufacturing industries .
5. Write two points of distinction between hydro electricity and thermal electricity .
Ans:
i) Hydro electricity is generated by fast flowing water , which is renewable resource . Thermal electricity is generated by using fossil fuels , which is non-renewable resource .
ii) Generation of hydro electricity does not cause pollution but generation of thermal electricity causes pollution .
6. Why is their a deep need to use renewable energy sources ?
Ans:
i) Rising prices of oil and gas and their potential shortages have raised uncertainties about the security of energy supply in future .
ii) Increasing use of fossil fuels causes serious environmental problems .
7. Why do you think solar energy has a bright future in India ?
Ans:
i) India is a tropical country , so it is blessed with abundance of sunlight .
ii) Use of solar energy will minimize the dependence of rural houses on firewood and dung cakes . This will contribute to environment conservation and adequate supply of manure in agriculture .
8. Setting of gobar gas plants should be encouraged in rural India’ Why ?
Ans:
i) Gobar gas plants provide double benefits to the farmer in the form of energy and improved quality of manure .
ii) It also prevents the loss of trees and manure due to burning of fuel wood and cow dung cakes .
9. ‘There is an urgent need to develop a sustainable path of energy development’ Why ? OR Why is it necessary to conserve energy resources ?
Ans:
i) Energy is a basic requirement for economic development . Every sector of national economy – agriculture , industry , transport , commercial and domestic – needs inputs of energy .
ii) The economic development plans require increasing amount of energy .
10. Why is it said that energy saved is energy produced ?
Ans:
i) We can use public transport system instead of individual vehicle .
ii) We can switch off electricity when not in use .
iii) We can use power saving devices and use non-conventional sources of energy .