Minerals and power resources

Q1) Distinguish between

  a) High grade ore and low grade ore

High grade ore	low grade ore
Mineral content is high	Mineral content is low
Very less impurities	Very high impurities

  b)  Wind energy and geo thermal energy

Wind energy: is a pollution free, inexhaustible source of energy. In this, the kinetic energy of wind is converted into electrical energy through turbines.

Wind mills have been used for grinding grain and lifting water since the ancient times.

Wind farms with clusters of such wind mills are located in coastal region and mountain where strong and steady winds blow.

Netherland, Germany, Denmark, USA and Spain are noted for their wind energy production. The wind power plant at Lamba in Gujarat is the largest in Asia. Tamil meets a sizable share of its energy needs from wind farms.

Geothermal energy: heat energy obtained from the earth is called geothermal energy. The hot water that gushes out through natural geysers or geothermal springs is used to produce thermal energy.

Geothermal energy has been used for cooking, heating, washing and bathing for several year in

USA and Central America.

In India, geothermal plants are located in Noni Karan in Himarhal, Pradosh and Puga valley in Ladakh.

  c)  Drilling and quarrying  

Drilling: petroleum and natural gas occur far below the earth’s surface. Deep wells are bored  or drilled to take them out.

Drilling can also be done off shore.

Quarrying: minerals that lie near the surface are simply dug out of the ground through a process called open cast mining.

The opening thus formed is called an open pit area quarry

Q2) name the following

1)   The mineral which commonly used in food

Ans:

Sodium chloride

2)  The minerals found in Europe

Ans:

Copper, Lead and Zinc

3)  Any four minerals found in India.

Ans:

Iron ore, Bauxite, Mica and Manganese.

4) Any three non-convential  sources of energy.

Ans:

Solar energy, Wind energy and tidal energy.

5)  Two places in India where geothermal stations are located.

Ans:

Mani Karan in Himachal Pradesh and Puja valley in Ladakh.

Q3) Give reasons

1)   Minerals need to be conserved for sustainable development

Ans:

·       Minerals take a very long time to develop and so they can’t be replenished immediately at the time of need .

·       It’s necessary to reduce wastage in the process of mining .

·       Recycling of metals is another way in which the mineral resources can be conserved.

2)  Why it is important to resort the use of non-conventional  sources of energy

Ans:

The burning of fossil fuels releases carbon dioxide in the atmosphere. This causes atmosphere pollution.

If we continue to use fossil fuels in an unrestrained manner, it will soon be exhausted. Therefor it is important to resort the use of non-conventional sources of energy.

Q4) What are minerals? What are the different types of minerals?

Ans:

A mineral is a naturally occurring substance found in the earth’s crust. Minerals have distinct physical properties such as colour, hardness and chemical properties such as solubility.

Like all  natural resources, minerals are distributed unevenly .

On the basis of composition, minerals are classified mainly as metallic and non-metalic minerals. Metallic minerals contain metals in raw forms .

 for example : Iron ore, Copper, Gold, Silver.

Non-metalic minerals do not contain any metallic substances. They are either organic or inorganic. Organic minerals contain carbon .

Examlpes of organic minerals: Coal, Petroleum and natural gas.

Examlpes of inorganic minerals: Mica, Limestone and graphite .

Q5) Define Ore ? How are they classified ?

Ans:

A rock which contains enough minerals to make it economically valuable for mining is called an Ore. Ores are classified as high grade Ores and low grade Ores. In the high grade Ores, the mineral content is high and impurities are less. In the low grade Ores, mineral content is low and the impurities are high.

Q6) What is mining ? What are the different types of mining?

Ans:

 Extraction ( taking out) of minerals from the rock is called mining.

The different types of mining are:

a) Open cast mining

b)   Shaft mining

c)  Drilling

Q6) What is the mineral Ore used in the manufacturing of Aluminium?

Ans:

Bauxite

Q7) Define hydroelectricity. What are its advantages ?

Ans:

Water from rivers and rain is stored in drums. This water falls  from great heights onto turbine blades making the blades rotate. The rotating blades then turn the generators to produce electricity. This is called hydroelectricity.

Its advantages are:

-      Renewable source of energy

-      It does not pollute the air.

Q8) What is tidal energy ?

Ans:

 Energy generated from tides is called tidal energy . tidal energy is harnessed  by building dams at narrow openings along the tidal belts of a sea. During high tide the energy of the tides is used to turn the turbines installed in the dam to produce electricity.

Q9) Mention the advantages of Biogas?

Ans:

Bio gas is energy generated from dead and decayed organic matter ( dead plants, animal dung, Kitchen waste, etc)

In biogas, digesters, bio waste  is decompressed by bacteria to emit biogas. The biogas ( fuel ) is a mixture of methane and Carbon dioxide. It is an excellent fuel for cooking, domestic lighting inrural areas and for producing organic manure .