New Getting Ahead In Social Studies Class 8 Solutions Chapter - 4 Geography | Mineral and Power Resources | Solved Question and Answers

 

Part II: Geography

Chapter – 4

Mineral and Power Resources

        

I.                  Distinguish between

1.     High grade ore and Low-grade ore

Ans: In the high-grade ores, the mineral content is high and impurities are less. In the low-grade ore, minerals content is low and impurities are more.

 

2.     Wind energy and geothermal energy

Ans:  Wind Energy: When energy is air pollution, inexhaustible source of energy., in this, the kinetic energy of wind is converted into electrical energy through turbines.

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.

 

3.     Drilling and quarrying

Ans: Drilling:  Deep wells are bored to take minerals out, this process is called drilling whereas Quarrying is simply digging out the minerals that lie near the surface.

 

II.               Name the following:

 

1.     The mineral which is commonly used in food.

Ans: Common Salt

 

2.      Three minerals found in Europe.

Ans: Copper, lead, zinc and nickel

 

3.     Any four minerals found in India.

Ans: Iron-ore, Bauxite, Copper and limestone.

 

4.     Any three non-conventional sources of energy.

Ans: Hydroelectricity, solar energy, wind energy and tidal energy.

 

5.     Two places in India where geothermal station are located.

Ans: Manikaran in Himachal Pradesh and Puga Valley in Ladakh.

 

 

 

III.           Give reason

1.     Minerals need to be conserved for sustainable development.

Ans: Since minerals take a very long time to develop and cannot be replenished immediately at the time of need. Therefore, minerals need to be conserved for sustainable development.

 

2.     It is important to resort to non-conventional power resources.

Ans:  It is important to resort to non-conventional power resources because they are renewable source of energy. They help in reducing global warming whereas the burning of fossil fuel releases carbon dioxide into the atmosphere.

 

IV.            Answer the following questions

1.     What are minerals? What are the different types of minerals?

Ans: a mineral is a naturally occurring substance found in the earth’s crust.

The different types of minerals are metallic and non-metallic minerals.

 

2.     Define ore.  How are they classified?

Ans: A rock which contain enough minerals to make it economically viable for mining is calling Ore. Ore are classified as high-grade ores and low-grade ores.

 

3.     What is mining? What are the different types of mining?

Ans: Extraction (or taking out) of minerals and minerals fuel from rock called mining.

The different types of mining are -     a. open - cast mining,

b. shaft mining and

c. drilling.

   

4.     What is the mineral ore used in the manufacturing of aluminium?

Ans: Bauxite is the most common aluminium ore. Approximately 98% of primarily aluminium production is based on bauxite.

 

5.     How are power resource classified? Give example for each. Compare the relative advantage and disadvantage of both types of energy.

Ans: Power resources can be broadly classified - as conventional and non-conventional resource.

Conventional source of energy includes like firewood and mineral fuel like coal, petroleum and natural gas etc.

Some of the advantage  - this fuels are essential for generating power. They are also known as fossil fuel or energy resources. It is an exhaustible resource i.e.  these resources are limited.

 

Non-conventional sources of energy are those that are continuously renewed by natural process. Example are- solar energy, wind energy, bioenergy from biofuels, hydroelectricity power, geothermal energy etc.

Some of the advantages are - this energy source are nonpolluting and It is an Inexhaustible.

 

6.     Define hydroelectricity. what are its advantages?

Ans: Water from river and rain is stored in dams. This water falls from great height onto turbine blade making the blades rotate. The rotating blades then turns the generator to produce electricity stop this is called hydroelectricity or hydel power.

Advantages: i. It is an inexhaustible energy.

                     ii. It is non-polluting

 

7.     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.

 

8.     Mention the advantages of biogas.

Ans:

                                                       i.             It is low cost.

                                                     ii.            it is very easy to operate.

                                                  iii.            It makes uses of bio waste.

 

 

 

MCQ
 
1.     c,
2.     c,
3.     a,
4.     d,
5.     a,
6.     c,
7.     a,
8.     d,
9.     c, d