Extra 30 long-answer questions based on Chapter 3: Minerals and Power Resources (Class 8 Geography).
1. What are minerals? Explain their types.
Answer:
Minerals are naturally occurring substances with a definite chemical composition found in the Earth’s crust.
Types of minerals:
Metallic Minerals
– Contain metals (e.g., iron, copper).
Non-metallic Minerals
– Do not contain metals (e.g., mica, limestone).
Energy Minerals
– Used for energy production (e.g., coal, petroleum).
2. What are the different methods of mineral extraction?
Answer:
Mining
– Extraction of minerals from rocks and soil.
Open-cast mining
– Minerals extracted from shallow depths.
Shaft mining
– Deep mining using tunnels and shafts.
Drilling
– Boring deep wells for petroleum and natural gas.
Quarrying
– Extraction of minerals from surface rocks.
3. What are ferrous and non-ferrous minerals? Give examples.
Answer:
Ferrous minerals
contain iron (e.g., iron ore, manganese).
Non-ferrous minerals
do not contain iron (e.g., bauxite, copper).
Differences:
Ferrous minerals are used in steel-making industries.
Non-ferrous minerals are used in electrical and automobile industries.
Iron ore is an example of a ferrous mineral, while bauxite is a non-ferrous mineral.
4. What is an ore? Explain with examples.
Answer:
An ore is a mineral from which metals can be profitably extracted.
Examples:
Bauxite
– Used to extract aluminium.
Hematite
– Used to extract iron.
Cinnabar
– Used to extract mercury.
5. Why is coal an important fossil fuel?
Answer:
It is used in thermal power plants to generate electricity.
It is used in industries like iron and steel.
It is an important source of domestic fuel in rural areas.
It provides coke, which is used in the metallurgical industry.
It is a cheap and widely available energy source.
6. What are the different types of coal?
Answer:
Anthracite
– Best quality, high carbon content, burns without smoke.
Bituminous
– Most commonly used, moderate carbon content.
Lignite
– Low carbon content, brown in colour
, used for power generation.
Peat
– Lowest quality, high moisture content, not used widely.
7. Why is petroleum known as “black gold”?
Answer:
It is a valuable fossil fuel.
It is used in transportation, industries, and households.
It is refined into petrol, diesel, kerosene, etc.
It has high economic value.
It is crucial for energy security.
8. What are the advantages of natural gas?
Answer:
It is a clean-burning fuel.
It has high energy efficiency.
It is used in industries, power plants, and households.
It reduces dependence on coal and petroleum.
It emits less carbon dioxide compared to other fossil fuels.
9. What is hydropower? Explain its advantages.
Answer:
Hydropower is energy generated by moving water using dams and turbines.
Advantages:
It is a renewable energy source.
It does not cause pollution.
It helps in water conservation.
It is cost-effective in the long run.
It reduces dependence on fossil fuels.
10. What are the disadvantages of hydroelectric power?
Answer:
Dams submerge large areas of land.
It affects aquatic ecosystems.
It leads to displacement of people.
It requires high investment.
It is dependent on rainfall.
11. How is nuclear energy produced? What are its advantages?
Answer:
Nuclear energy is generated by nuclear fission using uranium or thorium.
Advantages:
It produces a large amount of energy.
It does not cause air pollution.
It requires a small amount of fuel.
It is a reliable energy source.
12. What are the disadvantages of nuclear energy?
Answer:
Radioactive waste disposal is difficult.
Nuclear accidents can be disastrous.
High initial costs for setting up power plants.
Security concerns regarding nuclear material.
13. What are the advantages of solar energy?
Answer:
It is abundant and renewable.
It does not cause pollution.
It reduces dependence on fossil fuels.
It is useful in remote areas.
It reduces electricity costs.
14. What are the limitations of solar energy?
Answer:
Solar panels are expensive.
Energy production depends on sunlight.
Large areas are required for solar farms.
Storage of solar energy is costly.
15. Why is wind energy considered a renewable resource?
Answer:
It is naturally available and inexhaustible.
It does not produce pollution.
It reduces dependency on fossil fuels.
It can be generated in coastal and desert areas.
16. What are the disadvantages of wind energy?
Answer:
Wind speed must be consistent.
Wind turbines require large open areas.
High initial setup costs.
Noise pollution from turbines.
17. What is geothermal energy? How is it used?
Answer:
Geothermal energy is obtained from heat inside the Earth.
Uses:
Generating electricity in geothermal power plants.
Heating homes and buildings.
Industrial applications.
Agricultural greenhouse heating.
18. What is tidal energy? What are its advantages?
Answer:
Tidal energy is generated by the movement of ocean tides.
Advantages:
It is renewable and pollution-free.
It is predictable and reliable.
It produces large amounts of energy.
It reduces dependence on fossil fuels.
19. How does mining affect the environment?
Answer:
Deforestation and habitat destruction.
Soil erosion and land degradation.
Water pollution due to chemical waste.
Air pollution from dust and emissions.
20. What are some ways to conserve minerals?
Answer:
Recycling metals and minerals.
Using alternative materials.
Mining responsibly with environmental protection.
Reducing excessive use of minerals.
