Mineral and Power Resources
Welcome to HSLC Guru. In this article we present a complete English-medium study guide for Class 8 Social Science (Geography) Chapter 3 — Mineral and Power Resources, prepared strictly according to the latest ASSEB (Assam State School Education Board) syllabus. This chapter explores the substances that lie hidden inside the earth’s crust and the energy sources that power our industries, transport, homes and farms. You will learn the definition and classification of minerals, their global and Indian distribution, methods of extraction, and the importance of conservation. The article also explains conventional and non-conventional power resources, identifies major production centres in India, and stresses sustainable use. Each section is followed by textbook questions, additional MCQs, fill-in-the-blanks, true/false statements and a glossary so that students can revise quickly and answer confidently in examinations.
Summary
A mineral is a naturally occurring homogeneous substance with a definite chemical composition and physical properties. Minerals form the raw material for almost every industry — from automobiles and aircraft to medicines and electronics. They are broadly classified into two groups. Metallic minerals contain metals and are further divided into ferrous minerals (those containing iron, such as iron ore, manganese, chromite and nickel) and non-ferrous minerals (which do not contain iron, such as copper, bauxite, tin, lead and zinc). Non-metallic minerals do not yield metal on smelting; examples include limestone, mica, gypsum, dolomite and salt. Energy or fuel minerals such as coal, petroleum, natural gas and uranium are sometimes treated as a separate category because they release energy when burnt or processed.
Minerals are not evenly distributed across the world. Iron ore is mined heavily in Russia, Ukraine, USA, Canada, China, Brazil, Australia and India. Bauxite, the chief ore of aluminium, is found in Australia, Guinea, Brazil and India. Africa is rich in gold, diamond, copper and chromite. South America has large reserves of copper, iron, gold and silver. North America yields iron, copper, nickel, gold, silver and platinum. Within India, the north-eastern plateau region — comprising Chhattisgarh, Jharkhand, Odisha, West Bengal and parts of Andhra Pradesh — is the richest belt for iron, manganese, coal, mica and bauxite. Rajasthan supplies copper and zinc, Gujarat and Assam provide petroleum, and Karnataka has gold and iron ore. Assam holds an important place in petroleum and natural gas production, with Digboi, Naharkatiya and Moran being historic oilfields.
Minerals are extracted by different methods according to the depth and nature of the deposit. Open-pit (open-cast) mining is used when minerals lie close to the surface and is the cheapest method. Shaft mining or deep mining is adopted for deposits buried far below the ground; vertical shafts are sunk to bring out the ore. Drilling is used for liquid and gaseous minerals such as petroleum and natural gas, where deep wells are bored. Quarrying is the extraction of stones, marble, slate and similar materials lying near the surface. Because minerals take millions of years to form and the existing reserves are exhaustible, conservation is essential. Conservation measures include planned and controlled use, recycling of metals, substitution by cheaper materials, use of improved technology to reduce wastage, and prevention of illegal mining.
Power or energy resources are classified as conventional and non-conventional. Conventional sources are those that have been in use for a long time and are mostly exhaustible — coal, petroleum, natural gas, firewood and even hydro and nuclear energy in many textbooks. India’s main coalfields are in Jharia, Bokaro, Raniganj, Korba and Singrauli. Petroleum is produced in Assam (Digboi, Naharkatiya, Moran), Gujarat (Ankleshwar) and offshore Mumbai High. Major hydro-power stations include Bhakra Nangal, Damodar Valley and Hirakud. Nuclear power plants operate at Tarapur, Rana Pratap Sagar, Kalpakkam, Narora and Kaiga. Non-conventional sources are renewable, clean and inexhaustible — solar energy, wind energy, tidal energy, geothermal energy, biogas and biomass. India is among the leading producers of wind energy (Tamil Nadu, Gujarat, Maharashtra) and solar energy (Rajasthan, Gujarat). Sustainable energy use means meeting today’s demand without harming the ability of future generations to meet theirs, by saving electricity, using public transport, switching to LED lights, and adopting renewable sources wherever possible.
Textbook Questions and Answers
A. Very Short Answer Questions (1 Mark)
Q1. What is a mineral?
Answer: A mineral is a naturally occurring substance with a definite chemical composition and certain physical properties.
Q2. Name two ferrous minerals.
Answer: Iron ore and manganese.
Q3. Which mineral is known as black gold?
Answer: Petroleum is known as black gold.
Q4. Name the oldest oilfield of India.
Answer: Digboi in Assam is the oldest oilfield of India.
Q5. What is open-cast mining?
Answer: When minerals lying near the surface of the earth are extracted by removing the surface layer, the method is called open-cast or open-pit mining.
Q6. Name two non-conventional sources of energy.
Answer: Solar energy and wind energy.
Q7. Which is the chief ore of aluminium?
Answer: Bauxite is the chief ore of aluminium.
Q8. Name a state of India famous for wind energy.
Answer: Tamil Nadu is famous for wind energy production.
Q9. Where is the Tarapur Nuclear Power Plant located?
Answer: Tarapur Nuclear Power Plant is located in Maharashtra.
Q10. What is biogas?
Answer: Biogas is the gas produced by the decomposition of organic waste, mainly cattle dung, in the absence of air.
B. Short Answer Questions (2-3 Marks)
Q1. Distinguish between metallic and non-metallic minerals.
Answer: Metallic minerals contain metal in their composition and yield metal on smelting; examples are iron ore, copper, bauxite and gold. Non-metallic minerals do not contain metal and do not produce metal on smelting; examples are limestone, mica, gypsum and salt. Metallic minerals are usually associated with igneous and metamorphic rocks, while non-metallic minerals are mostly found in sedimentary rocks.
Q2. Differentiate between ferrous and non-ferrous minerals with examples.
Answer: Ferrous minerals are metallic minerals that contain iron, for example iron ore, manganese, chromite and nickel. They form the backbone of the iron and steel industry. Non-ferrous minerals are metallic minerals that do not contain iron, for example copper, bauxite, lead, zinc and tin. They are widely used in electrical, automobile and packaging industries.
Q3. What is meant by conservation of minerals? Mention any two methods.
Answer: Conservation of minerals means using mineral resources in a careful and planned manner so that they last longer for the future. Two methods are: (i) recycling of used metals like iron, copper and aluminium, and (ii) using improved mining technology to reduce wastage during extraction and processing.
Q4. Distinguish between conventional and non-conventional sources of energy.
Answer: Conventional sources of energy are those that have been in use for a long time and are mostly exhaustible, such as coal, petroleum, natural gas and firewood. Non-conventional sources are comparatively new in use, renewable and pollution-free, such as solar, wind, tidal, geothermal and biogas energy. Conventional sources cause more pollution while non-conventional sources are eco-friendly.
Q5. Why is petroleum called liquid gold or black gold?
Answer: Petroleum is called liquid gold or black gold because of its black colour, high commercial value and wide range of uses. It is the source of petrol, diesel, kerosene, lubricants and many petrochemical products. Its price and availability strongly influence the world economy.
Q6. Mention any three uses of solar energy.
Answer: (i) Solar energy is used to generate electricity through photovoltaic cells. (ii) It is used in solar cookers, solar water heaters and solar lanterns. (iii) It is used to operate traffic signals, calculators, water pumps and street lights in many areas.
C. Long Answer Questions (5-6 Marks)
Q1. Explain the classification of minerals with suitable examples.
Answer: Minerals are classified mainly into two broad groups — metallic and non-metallic. Metallic minerals are those that contain metal and yield metal on smelting. They are further divided into ferrous and non-ferrous minerals. Ferrous minerals contain iron and form the basis of the iron and steel industry; common examples are iron ore, manganese, chromite, cobalt and nickel. Non-ferrous minerals do not contain iron but are equally important for industries; examples include copper, bauxite, lead, zinc, tin and gold. Non-metallic minerals do not contain metal and do not yield metal on smelting; examples are limestone, mica, gypsum, dolomite, salt and graphite. They are largely used in cement, fertiliser, electrical and chemical industries. Apart from these, energy or fuel minerals like coal, petroleum, natural gas and uranium are often treated as a separate category because they are mainly used to produce energy. This classification helps in studying their distribution, uses and conservation in a systematic manner.
Q2. Describe the major methods of extracting minerals from the earth.
Answer: Minerals are extracted from the earth by four main methods. (i) Open-pit or open-cast mining is used when minerals lie close to the surface; the topsoil and rocks are removed and the ore is dug out. It is the cheapest and least dangerous method and is used for coal, iron ore and bauxite. (ii) Shaft or deep mining is adopted for minerals lying far below the surface. Vertical shafts and horizontal galleries are dug to reach the deposit; this method is costly and risky. (iii) Drilling is used for liquid and gaseous minerals such as petroleum and natural gas. Deep bore-wells are sunk through layers of rock and the fuel is brought to the surface by pumps or natural pressure. (iv) Quarrying is the extraction of building stones, marble, slate and similar materials that lie just on the surface; the material is broken or cut and lifted out. The choice of method depends on the depth, quality, quantity and economic value of the mineral deposit.
Q3. Discuss the distribution of important minerals in India.
Answer: India is rich in a variety of minerals, but they are unevenly distributed. The north-eastern plateau region covering Chhattisgarh, Jharkhand, Odisha, West Bengal and parts of Andhra Pradesh is called the mineral heartland of India. Iron ore is found mainly in Odisha (Sundargarh, Keonjhar), Jharkhand (Singhbhum), Chhattisgarh (Bailadila) and Karnataka (Bellary, Hospet). Manganese is mined in Odisha, Madhya Pradesh, Maharashtra and Karnataka. Bauxite is found in Odisha, Jharkhand, Gujarat and Maharashtra. Copper is produced in Rajasthan (Khetri) and Jharkhand (Singhbhum). Mica comes from Jharkhand, Bihar and Andhra Pradesh. Coal is mined in Jharia, Bokaro, Raniganj, Korba and Singrauli, while petroleum is obtained from Assam (Digboi, Naharkatiya, Moran), Gujarat (Ankleshwar) and offshore Mumbai High. Assam also produces natural gas in large quantities. This uneven distribution affects industrial location and regional development in the country.
Q4. Explain the importance of non-conventional sources of energy. Why are they preferred today?
Answer: Non-conventional sources of energy include solar, wind, tidal, geothermal, biogas and biomass energy. They are important for several reasons. First, conventional sources like coal and petroleum are exhaustible and their reserves are decreasing rapidly, so we need alternative sources. Second, non-conventional sources are renewable; they are continuously available from nature and will not be depleted. Third, they are pollution-free and eco-friendly; they do not release harmful gases that cause global warming or acid rain. Fourth, they are useful in remote and rural areas where supply of conventional energy is difficult, for example solar lanterns and biogas plants in villages. Fifth, the cost of equipment is gradually decreasing, making them economical in the long run. Because of these advantages, governments and people are now preferring non-conventional energy and India has launched many programmes to promote solar parks, wind farms, biogas plants and small hydro projects.
Q5. What is sustainable use of energy? Suggest some measures to achieve it.
Answer: Sustainable use of energy means using energy resources in such a way that the present needs are fulfilled without endangering the ability of future generations to meet their own needs. Since fossil fuels are limited and cause pollution, sustainable use is essential. Some measures are: (i) switching off lights, fans and appliances when not in use; (ii) using energy-efficient devices like LED bulbs, BEE star-rated appliances and improved chullahs; (iii) using public transport, bicycles or walking instead of private vehicles for short distances; (iv) increasing the share of renewable sources such as solar and wind in the energy mix; (v) recycling and reusing materials so that less energy is spent on fresh production; (vi) creating awareness through education and campaigns. By following these steps, we can save energy, reduce pollution and ensure a better environment for the coming generations.
Additional Multiple Choice Questions
Q1. Which of the following is a ferrous mineral?
(a) Copper (b) Bauxite (c) Manganese (d) Mica
Answer: (c) Manganese.
Q2. The ore of aluminium is —
(a) Hematite (b) Bauxite (c) Limestone (d) Gypsum
Answer: (b) Bauxite.
Q3. Digboi oilfield is located in which state?
(a) Gujarat (b) Rajasthan (c) Assam (d) Odisha
Answer: (c) Assam.
Q4. Which of the following is a non-conventional source of energy?
(a) Coal (b) Petroleum (c) Solar (d) Natural gas
Answer: (c) Solar.
Q5. Bhakra Nangal is associated with —
(a) Coal mining (b) Hydro-electricity (c) Nuclear power (d) Petroleum
Answer: (b) Hydro-electricity.
Q6. The method used to extract petroleum is —
(a) Quarrying (b) Open-pit mining (c) Drilling (d) Shaft mining
Answer: (c) Drilling.
Q7. Which state is famous for Khetri copper mines?
(a) Rajasthan (b) Madhya Pradesh (c) Karnataka (d) Bihar
Answer: (a) Rajasthan.
Q8. Geothermal energy comes from —
(a) The sun (b) Hot rocks inside the earth (c) Sea waves (d) Wind
Answer: (b) Hot rocks inside the earth.
Q9. Jharia coalfield is located in —
(a) Odisha (b) Jharkhand (c) Madhya Pradesh (d) West Bengal
Answer: (b) Jharkhand.
Q10. Which of the following is a non-metallic mineral?
(a) Iron ore (b) Mica (c) Copper (d) Manganese
Answer: (b) Mica.
Fill in the Blanks
Q1. A naturally occurring substance with a definite chemical composition is called a __________.
Answer: mineral.
Q2. __________ is the chief ore of iron used in the steel industry.
Answer: Hematite (iron ore).
Q3. Petroleum and natural gas are extracted by the method of __________.
Answer: drilling.
Q4. Energy obtained from the heat of the earth’s interior is called __________ energy.
Answer: geothermal.
Q5. __________ is the oldest oilfield of India, located in Assam.
Answer: Digboi.
True or False
Q1. Coal is a non-conventional source of energy.
Answer: False. Coal is a conventional source of energy.
Q2. Iron ore is a ferrous mineral.
Answer: True.
Q3. Solar energy is exhaustible.
Answer: False. Solar energy is renewable and inexhaustible.
Q4. Bauxite is the chief ore of aluminium.
Answer: True.
Q5. Tarapur is a hydro-electric power station.
Answer: False. Tarapur is a nuclear power station.
Glossary
| Term | Meaning |
|---|---|
| Mineral | A naturally occurring substance with a definite chemical composition and physical properties. |
| Ore | A rock from which a mineral can be extracted profitably. |
| Ferrous Mineral | A metallic mineral that contains iron, e.g., iron ore, manganese. |
| Non-Ferrous Mineral | A metallic mineral that does not contain iron, e.g., copper, bauxite. |
| Non-Metallic Mineral | A mineral that does not contain metal, e.g., mica, limestone, gypsum. |
| Open-cast Mining | Extraction of minerals lying near the surface by removing the top layer. |
| Shaft Mining | Extraction of minerals from deep below the surface through vertical shafts. |
| Drilling | Method used to extract liquid and gaseous minerals like petroleum and natural gas. |
| Quarrying | Cutting and removing stones, slate or marble from the surface of the earth. |
| Conventional Energy | Energy from sources used since long, mostly exhaustible — coal, petroleum, natural gas. |
| Non-Conventional Energy | Energy from renewable, eco-friendly sources — solar, wind, tidal, geothermal, biogas. |
| Hydro-electricity | Electricity generated by the force of falling water. |
| Nuclear Energy | Energy released by the fission of atoms of uranium or thorium. |
| Biogas | Gas produced by decomposition of organic waste in the absence of air. |
| Sustainable Use | Using resources in a way that meets present needs without harming future generations. |
| Conservation | Careful and planned use of resources to make them last longer. |