Minerals and Energy Resources

1. Why is conservation of minerals necessary?

1. <b>Economic dependence:</b> Agriculture and industry depend heavily on minerals and products manufactured from them.<br>2. <b>Limited deposits:</b> Economically workable deposits constitute only a small part of the Earth’s crust.<br>3. <b>Slow formation:</b> Geological processes require millions of years to form and concentrate usable minerals.<br>4. <b>Rapid consumption:</b> Minerals are consumed much faster than they are replenished; they are therefore finite and non-renewable.<br>5. <b>Increasing costs:</b> Continued mining involves greater depths and declining ore quality, making extraction more expensive. Conservation is necessary to maintain availability for future use.

2. Why is it necessary to develop non-conventional sources of energy in India?

1. <b>Increasing demand:</b> Population growth, urbanisation and industrialisation have increased energy requirements.<br>2. <b>Limited fossil fuels:</b> Coal, petroleum and natural gas are exhaustible and cannot meet growing demand indefinitely.<br>3. <b>Energy security:</b> Renewable energy reduces dependence on imported fuels and exposure to price fluctuations and shortages.<br>4. <b>Environmental protection:</b> Solar and wind power reduce fossil-fuel combustion, air pollution and greenhouse-gas emissions.<br>5. <b>Available potential:</b> India has abundant sunlight, wind, water and biomass that can support a sustainable and diversified energy supply.

3. “Solar energy has a bright future in India.” Explain.

1. India’s <b>tropical location</b> provides considerable scope for harnessing solar energy.<br>2. <b>Photovoltaic technology</b> converts sunlight directly into electricity.<br>3. Solar systems are useful in <b>rural and remote areas</b>, where conventional electricity supply may be difficult.<br>4. Solar power plants and devices can reduce households’ dependence on firewood and dung cakes.<br>5. Reduced firewood consumption supports environmental conservation, while retaining dung for agricultural use improves the availability of manure.

4. Explain five advantages of biogas plants in rural India.

1. <b>Available material:</b> Shrubs, farm waste and animal and human waste provide material for biogas production.<br>2. <b>Efficient fuel:</b> Biogas has higher thermal efficiency than kerosene, dung cakes and charcoal.<br>3. <b>Productive use of dung:</b> Cattle-dung plants, commonly called gobar-gas plants, provide useful domestic energy.<br>4. <b>Improved manure:</b> The remaining slurry provides manure of improved quality for agriculture.<br>5. <b>Conservation:</b> Biogas reduces the burning of firewood and dung cakes, helping conserve trees and prevent the loss of valuable manure.

5. Explain five harmful effects of mining on people and the environment.

1. <b>Pulmonary diseases:</b> Dust and harmful fumes make miners vulnerable to lung diseases.<br>2. <b>Accidents:</b> Collapsing mine roofs, inundation and fires threaten mine workers.<br>3. <b>Water contamination:</b> Mining activities contaminate local water sources.<br>4. <b>Land degradation:</b> Dumping waste and slurry damages land and soil resources.<br>5. <b>River pollution:</b> Waste entering streams and rivers increases pollution and harms surrounding ecosystems.<br><br><i>Stricter safety regulations and effective implementation of environmental laws are necessary to reduce these hazards.</i>

6. Suggest five measures to conserve energy resources.

1. <b>Public transport:</b> Use buses, trains and shared transport instead of individual vehicles wherever possible.<br>2. <b>Prevent wastage:</b> Switch off lights, fans and appliances when they are not required.<br>3. <b>Power-saving devices:</b> Use energy-efficient appliances and lighting to reduce electricity consumption.<br>4. <b>Renewable sources:</b> Adopt solar, wind, biogas and other suitable non-conventional sources.<br>5. <b>Efficient utilisation:</b> Maintain vehicles and machinery and improve industrial processes to obtain more useful output from each unit of energy.

7. Explain five modes of occurrence of minerals with examples.

1. <b>Veins and lodes:</b> Minerals occupy cracks and joints in igneous and metamorphic rocks. Examples include copper, zinc and lead.<br>2. <b>Beds or layers:</b> Deposition and accumulation in sedimentary rocks produce deposits such as coal and some iron ores.<br>3. <b>Residual deposits:</b> Weathering removes soluble material, leaving mineral-rich residues such as bauxite.<br>4. <b>Placer deposits:</b> Resistant minerals accumulate in river sands and valley floors; examples include gold, silver and tin.<br>5. <b>Ocean sources:</b> Seawater provides common salt, magnesium and bromine, while ocean beds contain manganese nodules.

8. Explain the importance of coal and describe its varieties.

Importance: Coal supplies energy for electricity generation, industries and domestic uses. Metallurgical coal is especially important for iron and steel production.

Varieties:

Variety	Characteristics & Importance
1. Peat	Formed from decaying vegetation in swamps; low carbon, high moisture, low heating capacity.
2. Lignite	Soft, low-grade brown coal with high moisture. Neyveli deposits in Tamil Nadu are used for electricity generation.
3. Bituminous	Most widely used commercial coal. High-grade metallurgical bituminous coal is valuable for smelting iron.
4. Anthracite	The highest-quality hard coal, with high carbon content.

9. Describe the four major iron-ore belts of India.

Iron-Ore Belt	Description & Key Locations
1. Odisha–Jharkhand	High-grade hematite occurs at Badampahar in Mayurbhanj and Kendujhar districts. Gua and Noamundi are important Jharkhand mines.
2. Durg–Bastar–Chandrapur	Extends through Chhattisgarh and Maharashtra. Bailadila contains high-grade hematite suited to steelmaking; exported through Vishakhapatnam.
3. Ballari–Chitradurga–Chikkamagaluru–Tumakuru	Karnataka’s belt contains large reserves. Kudremukh deposits are associated with slurry transport towards a port near Mangaluru.
4. Maharashtra–Goa	Includes Goa and Ratnagiri district. Though lower in quality, ores are efficiently exploited and exported through Marmagao.

10. Describe the distribution of coal in India.

1. Coal occurs mainly in rocks of two geological ages: <b>Gondwana</b> (over 200 million years old) and <b>Tertiary</b> (about 55 million years old).<br>2. Major Gondwana deposits occur in the <b>Damodar Valley</b>, extending through West Bengal and Jharkhand.<br>3. <b>Jharia, Raniganj and Bokaro</b> are important coalfields.<br>4. The <b>Godavari, Mahanadi, Son and Wardha valleys</b> also contain coal deposits.<br>5. Tertiary coal occurs in the north-eastern states of <b>Meghalaya, Assam, Arunachal Pradesh and Nagaland</b>. Important lignite reserves occur at Neyveli in Tamil Nadu.

11. Why are minerals considered non-renewable?

1. <b>Geological processes</b> take millions of years to form and concentrate usable minerals.<br>2. Minerals are extracted and consumed much faster than they are formed.<br>3. Exhausted deposits cannot be replaced within a human lifetime, making usable mineral resources effectively finite and non-renewable.

12. Explain three measures to conserve minerals.

1. <u>Planned management:</u> Use mineral resources through planned and sustainable management, avoiding unnecessary wastage.<br>2. <u>Improved technology:</u> Develop improved technology to make the extraction and use of low-grade ores economical.<br>3. <u>Recycling & substitutes:</u> Recycle metals, recover scrap and use suitable substitutes to reduce dependence on fresh deposits.

13. Explain the uneven distribution of minerals in India with examples.

1. <u>Peninsular rocks:</u> Contain most coal reserves, metallic minerals, mica and several non-metallic minerals.<br>2. <u>Sedimentary rocks:</u> Found in Gujarat, Assam and the peninsula’s western and eastern margins containing petroleum deposits.<br>3. <u>Northern alluvial plains:</u> Have few economic minerals because geological structures, processes and periods of formation differ between regions.

14. Why is mica important for electrical and electronic industries?

1. <u>Dielectric strength:</u> Mica possesses excellent dielectric strength, making it suitable for electrical insulation.<br>2. <u>Low power-loss:</u> Its low power-loss factor helps reduce energy loss in electrical applications.<br>3. <u>High voltage resistance:</u> Its insulating properties and resistance to high voltage make it valuable in electrical and electronic equipment.

15. Describe the distribution of mica in India.

1. <u>Chota Nagpur plateau:</u> Mica deposits occur along the northern edge, including the Koderma–Gaya–Hazaribagh belt.<br>2. <u>Rajasthan:</u> Ajmer and its surrounding areas form an important mica-producing region.<br>3. <u>Andhra Pradesh:</u> The Nellore mica belt is another important producing area.

16. Describe the formation and distribution of bauxite.

1. <u>Formation:</u> Develops through the decomposition of rocks containing aluminium silicates, leaving mineral-rich weathered material.<br>2. <u>Regions:</u> Important deposits occur in the Amarkantak plateau, Maikal hills and Bilaspur–Katni plateau region.<br>3. <u>Odisha:</u> Panchpatmali in Koraput district contains particularly important deposits.

17. Why is aluminium important? Name its principal ore.

1. <u>Principal ore:</u> Aluminium is extracted from bauxite.<br>2. <u>Strength & lightness:</u> It combines considerable strength with extreme lightness, making it useful in transport equipment and aircraft.<br>3. <u>Conductivity & malleability:</u> Its good conductivity and malleability make it valuable for electrical goods, utensils and numerous manufactured products.

18. Explain why copper is widely used and name important mining areas.

1. <u>Properties:</u> Copper is malleable and ductile, allowing it to be shaped into sheets and drawn into wires.<br>2. <u>Conductivity:</u> Its good conductivity makes it useful in electrical cables and electronic equipment.<br>3. <u>Mining areas:</u> Important mining areas include Balaghat in Madhya Pradesh, Khetri in Rajasthan and Singhbhum in Jharkhand.

19. Explain three uses of manganese.

1. <u>Steel manufacture:</u> Manganese is used in steel manufacture.<br>2. <u>Ferromanganese alloys:</u> Used to manufacture ferromanganese alloys (approx. 10 kg required for one tonne of steel).<br>3. <u>Other uses:</u> Also used in producing bleaching powder, insecticides and paints.

20. State the occurrence and uses of limestone.

1. <u>Occurrence:</u> Occurs in sedimentary rocks and is associated with calcium carbonate or calcium and magnesium carbonates.<br>2. <u>Cement industry:</u> It is a basic raw material for the cement industry.<br>3. <u>Iron smelting:</u> It is also required for smelting iron ore in blast furnaces.

21. Explain the geological occurrence of petroleum.

1. <u>Formations:</u> Petroleum occurs mainly in anticlines and fault traps in sedimentary formations.<br>2. <u>Accumulation:</u> It accumulates in porous limestone or sandstone, while impermeable layers prevent its escape.<br>3. <u>Structure:</u> In folded formations, oil collects near the crest of the upfold (natural gas occurs above it).

22. Describe the major petroleum-producing areas mentioned in the textbook.

1. Mumbai High: An important offshore petroleum-producing area.
   2. Gujarat: Has important deposits, including the Ankleshwar oilfield.
   3. Assam: India’s oldest oil-producing state, containing oilfields such as Digboi, Naharkatiya and Moran-Hugrijan.

23. Explain the importance of petroleum.

1. <u>Fuel:</u> Supplies fuel for transport, heating and lighting.<br>2. <u>Lubricants:</u> Provides lubricants for machinery.<br>3. <u>Nodal industry:</u> Refineries support synthetic-textile, fertiliser and chemical industries by supplying raw materials.

24. Explain three important uses of natural gas.

1. <u>Energy:</u> Supplies energy for electricity generation and industrial heating.<br>2. <u>Raw material:</u> Serves as a raw material in chemical, petrochemical and fertiliser industries.<br>3. <u>Transport & cooking:</u> Used as CNG for transport and PNG for domestic cooking.

25. Distinguish between thermal electricity and hydroelectricity.

Basis	Thermal electricity	Hydroelectricity
Generation	Burning fossil fuels produces steam or hot gases to drive turbines.	Moving water drives turbines.
Resource	Uses non-renewable coal, petroleum or natural gas.	Uses the renewable flow of water.
Environmental effect	Fuel combustion causes air pollution and greenhouse-gas emissions.	Generation involves no fuel burning, although dams affect ecosystems and settlements.

26. Distinguish between conventional and non-conventional energy sources.

Basis	Conventional sources	Non-conventional sources
Usage	Have been widely used for a long time.	Their large-scale use developed comparatively recently.
Examples	Coal, petroleum, natural gas and hydropower.	Solar, wind, tidal, geothermal energy and biogas.
Characteristics	Fossil fuels are exhaustible; hydropower is renewable.	Solar and wind are renewable and reduce fossil-fuel dependence.

Remember: Conventional does not always mean non-renewable.

27. Explain India’s potential for wind energy with examples.

1. <u>Conversion:</u> Wind turbines convert moving air into electricity, providing a renewable source of power.<br>2. <u>Tamil Nadu:</u> Has a major wind-farm cluster extending from Nagercoil to Madurai.<br>3. <u>Other regions:</u> Andhra Pradesh, Karnataka, Gujarat, Kerala, Maharashtra, Lakshadweep and Jaisalmer (Rajasthan).

28. What is geothermal energy? Explain its generation and name two locations.

1. <u>Definition:</u> Uses heat from the Earth’s interior.<br>2. <u>Generation:</u> Groundwater absorbs heat from hot rocks; steam reaches the surface to drive turbines.<br>3. <u>Locations:</u> Manikaran (Himachal Pradesh) and Puga Valley (Ladakh).

29. Explain how tidal energy is generated and name suitable areas in India.

1. <u>Structure:</u> A barrage with floodgates is constructed across a suitable coastal inlet.<br>2. <u>Generation:</u> Water enters at high tide and is trapped; during falling tide, it flows through turbines.<br>3. <u>Areas:</u> Gulf of Khambhat, Gulf of Kachchh and Sundarbans region.

30. Explain nuclear-energy generation and name important minerals used.

1. <u>Process:</u> Released by changing atomic structure, producing substantial heat.<br>2. <u>Generation:</u> Heat generates steam to drive turbines for electricity.<br>3. <u>Minerals:</u> Uranium and thorium (deposits in Jharkhand, Aravallis; Kerala's monazite sands).

31. Distinguish between magnetite and hematite.

Basis	Magnetite	Hematite
Iron content	Contains up to about 70% iron.	Contains about 50–60% iron.
Characteristic	Has excellent magnetic properties.	Has lower iron content than magnetite.
Importance	Particularly valuable in the electrical industry.	The most important industrial iron ore in terms of quantity used.

32. Explain three factors determining the economic viability of a mineral reserve.

1. <u>Concentration:</u> The ore must contain enough mineral to make extraction commercially worthwhile.<br>2. <u>Ease of extraction:</u> Geological structure, depth and accessibility affect mining costs.<br>3. <u>Closeness to markets:</u> Nearby markets reduce transport costs and make the deposit more economical.

33. Why are coal-based thermal power plants often located near coalfields?

1. <u>Bulky material:</u> Coal is bulky, making long-distance transport expensive.<br>2. <u>Weight loss:</u> It loses weight during use because a substantial portion becomes ash.<br>3. <u>Cost reduction:</u> Locating near coalfields reduces transport costs and maintains a regular fuel supply.

34. Explain why energy conservation is essential for sustainable development.

1. <u>Increasing consumption:</u> Agriculture, industry, transport and households require increasing amounts of energy.<br>2. <u>Judicious use:</u> Limited resources must be used judiciously to maintain supplies and reduce environmental damage.<br>3. <u>Sustainability:</u> Energy conservation and greater use of renewable sources together support sustainable development.