GEOGRAPHY
CHAPTER-3
MINERALS AND POWER RESOURCES
1. Define the term Ores. Where are the ores of metallic minerals generally located?
Answer: Rocks from which minerals are mined are known as ores.
- Minerals occur in different types of rocks. Some are found in igneous rocks, some in metamorphic rocks, while others occur in sedimentary rocks.
- The ores of metallic minerals are found in igneous and metamorphic rock formations that form large plateaus.
- Sedimentary rock formations of plains and young fold mountains contain non-metallic minerals like limestone
2. Quarrying can become a major environmental concern. Give reasons.
- Answer: Quarrying creates many problems for the environment and human beings.
- Fine dust particles spread in the air around a quarrying site and these Dust particles can cause respiratory problems.
- Quarrying also destroys natural vegetation and thus the home of many wild animals.
3. How is biogas generated?
Ans. – Organic waste such as dead plant and animal material, animal dung and kitchen waste can be converted into a gaseous fuel called biogas. Organic waste is decomposed by bacteria in biogas digesters to emit biogas which is essentially a mixture of methane and carbon dioxide.
4. What is tidal energy? How is it generated? Give major areas where it is generated?
- Ans. – Energy generated from tides is called tidal energy.
- Tidal energy can be harnessed by building dams at narrow openings of the sea.
- During high tide, the energy of the tides is used to turn the turbine installed in the dam to produce electricity.
- Russia, France and the Gulf of Kachchh in India have huge tidal mill farms.
5. Mention the raw materials which are used to make biogas.
Ans. – Organic waste such as dead plant and animal material, animal dung and kitchen waste are the raw materials used to make biogas.
6. How are rocks different from ores?
Ans- Difference between a rock and an ore is as follows –
ROCKS | ORES |
A rock is an aggregate of one or more minerals but without definite composition of constituent of mineral. | Rocks from which minerals are mined are known as ores. |
7. Name and explain the types of metallic minerals.
Ans – Metallic minerals may be ferrous or non-ferrous.
Ferrous minerals like iron ore, manganese and chromites contain iron. b. A non-ferrous mineral does not contain iron but may contain some other metal such as gold, silver, copper or lead.
8. Describe the different methods of extraction of metals.
Ans – The different methods of extracting metals are as follows –
- The process of taking out minerals from rocks buried under the earth’s surface is called mining.
- Minerals that lie at shallow depths are taken out by removing the surface layer; this is known as open-cast mining.
- Deep bores, called shafts, have to be made to reach mineral deposits that lie at great depths. This is called shaft mining.
- Petroleum and natural gas occur far below the earth’s surface. Deep wells are bored to take them out, this is called drilling.
- Minerals that lie near the surface are simply dug out, by the process known as quarrying.
9. Different types of minerals are found in different types of rocks? Explain with the help of examples from the World.
Ans – Minerals occur in different types of rocks.
- Some are found in igneous rocks, some in metamorphic rocks while others occur in sedimentary rocks.
- Generally, metallic minerals are found in igneous and metamorphic rock formations that form large plateaus.
- Example – a. Iron-ore in north Sweden, copper and nickel deposits in Ontario, Canada, iron, nickel, chromites and platinum in South Africa are examples of minerals found in igneous and metamorphic rocks.
- Sedimentary rock formations of plains and young fold mountains contain non metallic minerals like limestone.
- Example – a. Limestone deposits of Caucasus region of France, manganese deposits of Georgia and Ukraine and phosphate beds of Algeria.
- Mineral fuels such as coal and petroleum are also found in the sedimentary strata.
10. Why do we need to conserve minerals? How can we conserve them?
Ans. – we need to conserve minerals because-
- Minerals are a non-renewable resource.
- It takes thousands of years for the formation and concentration of minerals.
- The rate of formation is much smaller than the rate at which humans consume these minerals.
- We can conserve them by reducing wastage in the process of mining.
- Recycling of metals is another way in which the mineral resources can be conserved.
11. Compare the advantages and disadvantages of conventional and non -conventional resources?
Ans. –
Conventional Sources of Energy | Non-Conventional Sources of Energy |
Common in use since long time | Identified few decades ago |
Can be exhausted | Cannot be exhausted |
Pollute environment | Eco friendly |
12. What are minerals? What are the uses of minerals?
Ans- A naturally occurring substance that has a definite chemical composition is a mineral.
- The minerals have following uses –
- Minerals are used in many industries.
- Minerals which are used for gems are usually hard. These are then set in various styles for jewellery.
- Copper is another metal used in everything from coins to pipes.
- Silicon, used in the computer industry is obtained from quartz.
- Aluminum obtained from its ore bauxite is used in automobiles and airplanes, bottling industry, buildings and even in kitchen cookware.
13. What are the different types of minerals on the basis of composition? Explain.
Ans – On the basis of composition, minerals are classified mainly as metallic and non metallic minerals.
Metallic Minerals
- The metallic minerals contain metal in raw form.
- Metals are hard substances that conduct heat and electricity and have a characteristic lustre or shine.
- Iron ore, bauxite, manganese ore are some examples.
Non – Metallic Minerals
- The non-metallic minerals do not contain metals.
- Limestone, mica and gypsum are examples of such minerals.
- The mineral fuels like coal and petroleum are also non-metallic minerals.