Very Short Answer Type Questions
Short Answer Type Questions
1. Name and describe briefly methods of extraction.
2. Where are minerals found?
Answer: Minerals are found in different types of rocks. Metallic minerals are usually found in igneous and metamorphic rocks that form large plateaus. Examples: iron ore is found in north Sweden, copper and nickel in Canada. In igneous and metamorphic rocks in South Africa, iron, nickel, chromites and platinum are found. Non-metallic minerals are found in sedimentary rock formations. Limestone deposits are found in France. Mineral fuels such as coal and petroleum are found in sedimentary strata.
3. Describe the mineral distribution in North America.
Answer: The mineral deposits in North America are found in three zones: the Canadian region in the north of the Great Lakes, the Appalachian region and the Rocky Mountains in the West. Iron ore, nickel, gold, uranium and copper are mined in the Canadian Shield Region, coal in the Appalachian region. Western Cordilleras have vast deposits of copper, lead, zinc, gold and silver.
4. Write common uses of minerals.
Answer: Minerals are important in many industries. Minerals used in gems are usually very hard. These are then set in varying styles of jewellery. Iron and copper are metals used in almost everything. Copper is present in everything from coins to pipes and electricity wires. Silicon, obtained from the mineral quartz, is the base of computer industry. Aluminium, obtained from bauxite ore, and its alloys are used in aeroplanes due to their light weight. Aluminium is also used in kitchen cookware.
5. How is hydroelectricity, produced?
Answer: Hydroelectricity is produced from the energy possessed by water falling from great heights. River water is stored in dams. When rain water or river water falls from heights, it flows over turbine blades placed at the bottom of the dam. The moving blades are connected to a generator which produces electricity from this energy. This electricity is called hydroelectricity. The water discharged after its production is used for irrigation.
Long Answer Type Questions
1. Name and describe some non- conventional sources of energy.
Answer: Non-conventional power sources are those power sources that have come into use recently due to the depleting conventional resources and growing awareness. Solar energy, wind energy, geothermal energy, nuclear power and tidal energy are examples of non- conventional power sources.
Solar energy is the heat and light energy captured from the sun. Solar cells help to convert this energy to electricity. Solar energy is used in solar heaters, solar cookers, solar dryers, etc.
Wind energy is the energy possessed by moving air (wind). Windmills are used to convert wind energy to electricity. Wind farms having clusters of windmills located in coastal regions and mountain passes.
Nuclear power is energy possessed by the nuclei of atoms of naturally occurring radioactive elements like uranium-, thorium, etc.
Geothermal energy is the heat energy obtained from the inside of the earth. The temperature inside the earth increases as we go deeper. This heat is used to produce electricity. It is accessed in the form of hot springs. Tidal energy is the energy generated from tides. It is harnessed by building dams at narrow openings of the sea. Biogas is a gaseous fuel obtained from the decomposition of organic waste like dead plant and animal material or animal dung and kitchen waste. It is an excellent fuel for cooking and lighting, and is environment-friendly.
Non-conventional sources of energy are usually inexhaustible. They do not pollute the environment.
Nuclear power is emitted in large amounts.
Most non-conventional sources of energy cost less.
These forms of energy are safe to use and clean.
Disadvantages:
Wind mills are costly to set up. So using them to harness wind energy is costly, even though the electricity generated from it is cheap.
Setting up windmills disturbs radio and TV broadcast.
Harnessing tidal energy destroys natural habitats of wildlife.
Moreover, tidal energy is difficult to harness.
Obtaining nuclear energy from radioactive material generates radioactive waste. It is expensive too.
Biogas, although useful and renewable, contributes to greenhouse effect.
