JAC Class 8 Social Science Solutions Geography Chapter 3 Mineral and Power Resources

JAC Board Class 8th Social Science Solutions Geography Chapter 3 Mineral and Power Resources

JAC Class 8th Geography Mineral and Power Resources InText Questions and Answers

Page 25

Question 1.
Identify the Canadian Shield, the Appalachians, Western Cordilleras and Lake Superior with the help of an atlas.
Answer:
Students need to do it on their own.

Page 26

Question 2.
List uses of any five minerals.
Answer:
Uses of five minerals:

  1. Granite:
    Used as a building stone such monuments, statues. Also used in highway construction and railway ballast.
  2. Lead:
    Used in television tubes and batteries.
  3. Aluminum:
    Used in manufacturing aeroplane and automobiles. It is also used in canning and bottling industries.
  4. Copper:
    Used in electric cables and wires, switches, coins and jewelry.
  5. Gold:
    Used for scientific and electronic instruments, computer circuitry, aerospace industry. Also used in jewelry, medicine and dentistry.

JAC Class 8th Geography Mineral and Power Resources Textbook Questions and Answers

Answer The Following Questions.

(i) Name any three common minerals used by you every day.
Answer:
Three common minerals used by us every day are iron, aluminum and copper.

(ii) What is an ore? Where are the ores of metallic minerals generally located?
Answer:
Ores are the minerals which are rich in a particular element and can be mined. The ores of metallic minerals are generally located in igneous and metamorphic rock formations.

(iii) Name two regions rich in natural gas resources.
Answer:
Two regions which are rich in natural gas resources are:
In the world Russia and Norway.
In India Krishna Godavari Delta and Jaisalmer.

(iv) Which sources of energy would you suggest for
Answer:
Sources of energy suggested for:

  • Rural areas – Biogas and solar energy are feasible options.
  • Coastal areas – Tidal energy and hydel energy are good options.
  • Arid regions – Solar energy and wind energy are suitable options.

(a) rural areas
(b) coastal areas
(c) Arid regions

(v) Give five ways in which you can save energy at home.
Answer:
Five ways in which we can save energy at home are:

  • For cooking fuel use of biogas would save energy.
  • Misuse of electricity should be avoided such as switch off the lights and fans when not required.
  • Solar energy must be used as much as we can.
  • Energy efficient devices should be used such as LED bulbs and tubes.
  • While cooking using energy efficiently such as covering with lid, pressure cook, etc.

Tick the correct answer.

Question 2.
(i) Which one of the following is NOT a characteristic of minerals?
(a) They are created by natural processes.
(b) They have a definite chemical composition.
(c) They are inexhaustible.
(d) Their distribution is uneven.
Answer:
(c) They are inexhaustible.

(ii) Which one of the following is a leading producer of copper in the world?
(a) Bolivia
(b) Ghana
(c) Chile
(d) Zimbabwe
Answer:
(c) Chile

(iii) Which one of the following practices will NOT conserve LPG in your kitchen?
(a) Soaking the dal for some time before cooking it.
(b) Cooking food in a pressure cooker.
(c) Keeping the vegetables chopped before lighting the gas for cooking.
(d) Cooking food in an open pan kept on low flame.
Answer:
(d) Cooking food in an open pan kept on low flame.

Question 3.
Give reasons.

  1. Environmental aspects must be carefully looked into before building huge dams.
  2. Most industries are concentrated around coal mines.
  3. Petroleum is referred to as “black gold”.
  4. Quarrying can become a major environmental concern.

Answer:

  1. Environmental aspects must be carefully looked into before building huge dams because it can create imbalance and deforestation may happen. Humans, wild animals become displaced.
  2. Most industries are concentrated around coal mines because it ensures the availability of fuel and transportation costs get reduced.
  3. Petroleum is referred to as “black gold” because in the crude form it is in black colour and its derivatives are extremely valuable such as petroleum. Different products of petroleum are used in are day to day life such as petrol, diesel, kerosene.
  4. Quarrying can become a major environmental concern because pits are not covered so they may cause environmental threats after quarrying.

Question 4.

Distinguish between the followings.

  1. Conventional and
  2. Biogas and natural gas
  3. Ferrous and nonferrous minerals
  4. Metallic and nonmetallic minerals

1.

Conventional Sources of energy Non-conventional N Sources of energy
From long time they have been used. These sources have been identified in recent past.
These are mostly polluting. These are non-polluting
Firewood, coal are the examples. Wind energy, solar energy, tidal energy are the examples.

2.

Biogas Natural Gas
It is a non- conventional source of energy. It is a conventional source of energy.
It is a renewable source. It is a non-renewable source.
It is obtained from the decaying of the organic waste. It is a by-product which is obtained from the extraction of petroleum.

3.

Ferrous Minerals Non-ferrous N minerals
Minerals which contain iron are Ferrous minerals. Minerals which do not contain iron are Non- ferrous minerals.
Iron ore is a ferrous mineral. Limestone is a non- ferrous mineral.
These are magnetic in nature. These are non-magnetic in nature.
India has abundant of ferrous minerals. India is deficient of non-ferrous mineralsv

4.

Metallic Minerals Non-metallic Minerals
In raw form, metals are found. It does not contain metals.
New products can be obtained by melting them. On melting, they do not give new products.
These are associated with igneous rocks. These are associated with sedimentary rocks.
Bauxite is a metallic mineral. Gypsum is a non-metallic mineral.

 

Question 5.
Activity

  1. Use pictures from old magazines to show different kinds of fuels used by us in our lives and display them on your bulletin board.
  2. Design a poster highlighting energy conservation tips you would take for your school.
  3. Salma’s class took up an action campaign to do an energy audit of their school by surveying electricity consumption. They prepared survey sheets for the students of the school.

Answer:
Students need to do it on their own.

JAC Class 8th Geography Mineral and Power Resources Important Questions and Answers

Multiple Choice Questions 

Question 1.
Minerals are
(a) naturally occurring substances that have definite chemical compositions.
(b) artificially made substances that have a definite chemical compositions.
(c) human made substances that have definite chemical compositions.
(d) liquids and gases that are found everywhere.
Answer:
(a) naturally occurring substances that have definite chemical compositions.

Question 2.
Physical properties of minerals are
(a) population and economy.
(b) pollution and political factors.
(c) colour, density, hardness, and chemical properties such as solubility.
(d) weather and plant action.
Answer:
(c) colour, density, hardness, and chemical properties such as solubility.

Question 3.
The process of simply digging out minerals such as lead and coal that lie near the surface of the earth is called.
(a) drilling
(b) quarrying
(c) open cast mining
(d) none of these
Answer:
(b) quarrying

Question 4.
The colour of a rock if it contains a large amount of copper is.
(a) green
(b) quarrying
(c) silver
(d) red
Answer:
(b) quarrying

Question 5.
The world’s leading tin producers are:
(a) India, Pakistan, and Afghanistan
(b) India, China, and USA
(c) China, USA, and Austral
(d) China, Malaysia, and Indonesia
Answer:
(d) China, Malaysia, and Indonesia

Question 6.
Aluminum, obtained from its ore bauxite is used in.
(a) automobiles
(b) buildings
(c) airplanes
(d) all of these
Answer:
(d) all of these

Question 7.
The ways to conserve minerals so that they may also be available to future generations are
(a) reuse, reduce use, and recycle.
(b) reuse and recycle.
(c) reduce use and recycle.
(d) none of these
Answer:
(a) reuse, reduce use, and recycle.

Question 8.
The disadvantages of using firewood as a fuel are:
(a) It is polluting and promotes the greenhouse effect.
(b) It takes time to collect.
(c) It results in deforestation.
(d) All of these
Answer:
(a) It is polluting and promotes the greenhouse effect.

Question 9.
Natural gas is usually found with deposits of .
(a) firewood
(b) iron ore
(c) petroleum
(d) coal
Answer:
(c) petroleum

Question 10.
The main parts in a hydro-electric power station:
(a) a generator, a turbine, and a motor
(b) a water reservoir, a turbine, and a motor
(c) a generator, a rocket, and a turbine
(d) a water reservoir, a turbine, and a generator
Answer:
(d) a water reservoir, a turbine, and a generator

Very Short Answer Type Questions 

Question 1.
How many types of minerals have been identified and how many are considered as ore minerals?
Answer:
There are around 2,800 types of minerals which have been identified and only about 100 are considered ore minerals.

Question 2.
Which country has no minerals?
Answer:
Switzerland has no known minerals.

Question 3.
Which country is the largest producer of bauxite in the world?
Answer:
Australia is the largest producer of bauxite in the world.

Question 4.
What are the two naturally occurring radioactive elements?
Answer:
Uranium and Thorium are the two naturally occurring radioactive elements.

Question 5.
Which is the most abundantly found fossil fuel?
Answer:
The most abundantly found fossil fuel is coal.

Question 6.
In which place of India has huge tidal mill farms?
Answer:
Gulf of Kachchh in India has huge tidal mill farms.

Question 7.
Name the first country to develop hydroelectricity in the world.
Answer:
Norway was the first country in the world to develop hydroelectricity in the world.

Question 8.
Name two areas in Australia which have large deposits of gold.
Answer:
Kalgoorlie and Coolgardie areas of western Australia have the largest deposits of gold.

Question 9.
Where is the site of the world’s first solar and wind powered bus shelter?
Answer:
The site of the world’s first solar and wind powered bus shelter is in Scotland.

Question 10.
Name the places where the geothermal power plants located in India.
Answer:
In India, geothermal plants are located in Manikaran in Himachal Pradesh and Puga Valley in Ladakh.

Short Answer Type Questions 

Question 1.
CNG is considered an eco-friendly fuel. Why?
Answer:
Compressed natural gas (CNG) is a popular eco-friendly fuel because it causes less pollution than petroleum and diesel.

Question 2.
Give one advantage and one disadvantage of geothermal energy.
Answer:
Advantage – Clean, eco-friendly and always available. Disadvantages – Located far away from cities and so costly to transport the electricity.

Question 3.
What are the main types of power resources?
Answer:
The main types of power resources are conventional and non-conventional resources.

Question 4.
Explain in brief the mineral salt?
Answer:
The mineral salt is obtained from seas, lakes and rocks. India is one of the world’s leading producers and exporters of salt.

Question 5.
Coal is known as “buried sunshine”. Why?
Answer:
Coal is known as “Buried Sunshine” because the coal which we are using today was formed millions of years ago when giant ferns and swamps got buried under the layers of earth.

Question 6.
“All minerals are rocks but all rocks are not minerals”. Justify in brief.
Answer:
All minerals are rocks but all rocks are not minerals because more than 2,800 types of minerals have been identified but only about 100 are considered ore minerals which can be used.

Question 7.
Minerals are considered non. renewable. Why?
Answer:
Minerals are a non-renewable resource because it takes thousands of years for the formation. The rate of formation is much smaller than the rate at which the humans consume these minerals.

Question 8.
How do we get nuclear energy?
Answer:
We get nuclear power from energy stored in the nuclei of atoms of naturally occurring radioactive elements like uranium and thorium. These fuels undergo nuclear fission in nuclear reactors and emit power.

Question 9.
What are the nuclear power stations in India.
Answer:
The nuclear power stations in India are located in Kalpakkam in Tamil Nadu, Tarapur in Maharastra, Ranapratap Sagar near Kota in Rajasthan, Narora in Uttar Pradesh and Kaiga in Karnataka.

Question 10.
Distinguish between a rock and an ore.
Answer:
Difference between a rock and an ore:

A rock Ail ore
A rock is an aggregate of one or more minerals but without definite and fixed composition of constituent of mineral. Rocks from which minerals are mined are called ores.


Long Answer Type Questions 

Question 1.
What are the advantages and disadvantages of
(a) Coal
(b) Crude oil
Answer:
(a) Coal
Advantages

  • It is extensively available.
  • It is efficient to convert to electricity.
  • It offers a low capita investment.
  • It is a full time energy resource.

Disadvantages

  • It is a source of pollution.
  • It is bulky to transport.
  • It is not a renewable resource.
  • It creates high level of radiation.
  • Clean coal also has high level of methane.

(b) Crude oil Advantages

  • It is easier to transport such as tankers are used.
  • It is the basis of petro-chemical industry.
  • It can be extracted easily.
  • It is a powerful source of energy. Disadvantages
  • Depletion of oxygen due to oil spillage.
  • Pollutants released caused acid rain.
  • Exploration of new fuel is not easy.
  • It is a non-renewable source.

Question 2.
Briefly explain the method of extraction.
Answer:
The method of extraction consists of mining, drilling and quarrying.
(i) Mining:
The process of taking out minerals from rocks which are buried under the earth’s surface is called mining. Open-cast mining Minerals that lie at shallow depths are taken out by removing the surface layer, this is known as open-cast mining.

Shaft mining :
Deep bores called shafts have to be made to reach mineral deposits that lie at great depths. This is known as shaft mining.

(ii) Drilling:
Petroleum and natural gas occur far below the earth’s surface. Deep wells are bored to take them out. This process is known as drilling.

(iii) Question uarrying :
Minerals that lie near the surface are simply dug out, by the process known as quarrying.

JAC Class 8 Social Science Solutions

JAC Class 8 Social Science Notes Geography Chapter 3 Mineral and Power Resources

JAC Board Class 8th Social Science Notes Geography Chapter 3 Mineral and Power Resources

→ A mineral is a naturally occurring substance that has a definite chemical composition.

  • Minerals are not evenly distributed over the areas. They are concentrated in a particular area or rock formations.
  • Some minerals are found in regions which are not easily accessible such as the Arctic ocean bed and Antarctica.
  • Minerals are created by natural processes without any human interference. On the basis of their physical properties such as colour, density, hardness and chemical property such as solubility, they are classified and identified.

→ Types of Minerals:

  • On earth, there are over three thousand different minerals.
  • On the basis of composition, minerals are categorised as:
    • Metallic minerals
    • non-metallic minerals.
  • Metals in raw form are present in metallic minerals.
  • The hard substances that conduct heat and electricity and have a characteristic lustre or shine are known as metals. Iron ore, bauxite, manganese ore are some examples.

JAC Class 8 Social Science Notes Geography Chapter 3 Mineral and Power Resources

→ Metallic minerals are of two types:

  • Ferrous minerals are such as iron ore, manganese and chromites contain iron.
  • A non-ferrous mineral does not contain iron but may contain some other metal such as gold, silver, copper or lead.

→ Non-metallic minerals do not contain metals.

  • Limestone, mica and gypsum are non- metallic minerals.
  • The mineral fuels like coal and petroleum are also non-metallic minerals.
  • Minerals can be extracted by mining, drilling or quarrying.
  • Mining is the process of taking out minerals from rocks buried under the earth’s surface.

→ Mining is categorised into two:

  • Open cast mining
  • Shaft mining

→ In open-cast mining, minerals that lie at shallow depths are taken out by removing the surface layer.

  • In shaft mining, deep bores known as shafts, have to be made to reach mineral deposits that lie at great depths.
  • Petroleum and natural gas occur deep below the earth’s surface. Drilling is done to take them out and deep wells are bored.
  • Quarrying is the method in which minerals that lie near the surface are simply dug out.

→ Distribution of Minerals:

  • Metallic minerals are found in igneous and metamorphic rock formations that form large plateaus.
  • Iron-ore in north Sweden, copper and nickel deposits in Ontario, Canada, iron, nickel, chromites and platinum in South Africa are some of the examples of minerals found in these rocks.
  • Non-metallic minerals are found in sedimentary rock formations of plains and young fold mountains contain such as limestone.
  • Limestone deposits of Caucasus region of France, manganese deposits of Georgia and Ukraine and phosphate beds of Algeria are some examples. Coal and petroleum, the mineral fuels are also found in the sedimentary strata.

→ Asia:

  • China and India have large iron ore deposits. The continent produces more than half of the world’s tin.
  • The world’s leading tin producers are China, Malaysia and Indonesia.
  • China is in the leading position in production of lead, antimony and tungsten.
  • Asia also has deposits of manganese, bauxite, nickel, zinc and copper.

→ Europe:

  • Europe is the leading producer of iron-ore in the world.
  • Russia, Ukraine, Sweden and France have the large deposits of iron ore.
  • In eastern Europe and European Russia, minerals found are copper, lead, zinc, manganese and nickel.

JAC Class 8 Social Science Notes Geography Chapter 3 Mineral and Power Resources

→ North America:

  • The mineral deposits are situated in three zones:
    • the Canadian region north of the Great Lakes,
    • the Appalachian region and
    • the mountain ranges of the west.
  • In the Canadian Shield Region, iron ore, nickel, gold, uranium and copper are found.
  • In the Appalachians region, coal is found.
  • In Western Cordilleras, vast deposits of copper, lead, zinc, gold and silver are found.

→ South America:

  • The largest producer of high grade iron-ore in the world is Brazil.
  • The leading producers of copper are Chile and Peru.
  • Among the world’s largest producers of tin are Brazil and Bolivia.
  • In Venezuela, Argentina, Chile, Peru and Columbia, mineral oil is found.

→ Africa:

  • The world’s largest producer of diamonds, gold and platinum is Africa.
  • A major portion of the world’s gold is produced by South Africa, Zimbabwe and Zaire.
  • Copper, iron ore, chromium, uranium, cobalt and bauxite are found here.
  • In Nigeria, Libya and Angola, oil is found.

→ Australia:

  • The largest producer of bauxite in the world is Australia.
  • The largest deposits of gold is found in Kalgoorlie and Coolgardie areas of western Australia.
  • It is a leading producer of gold, diamond, iron ore, tin and nickel.

→ Antarctica:

  • Iron ore, gold, silver and oil are present in commercial quantities.
  • Sufficient and significant amount of deposits of coal in the Transantarctic Mountains and iron near the Prince Charles Mountains of East Antarctica is predicted.

→ Uses of Minerals:

  • Minerals are used in many industries in different forms.
  • Minerals which are used for gems and jewellery are usually hard. These are later processed.
  • Copper is used in almost everything from coins to pipes.
  • Silicon is used in the computer industry and is obtained from quartz.
  • Aluminum obtained from its ore.
  • In automobiles, airplanes, bottling industry, buildings and even in kitchen cookware, bauxite is used.

→ Conservation of Minerals:

  • Minerals are a non-renewable resource.
  • In the process of mining, it is necessary to reduce the wastage.
  • Another way in which the mineral resources can be conserved is recycling of metals.

JAC Class 8 Social Science Notes Geography Chapter 3 Mineral and Power Resources

→ Power Resources:

  • We need power or energy for industry, agriculture, transport, communication and defense.
  • Power resources may be broadly categorised as:
    • conventional resources
    • non-conventional resources.

→ Conventional Sources:

  • Those energy which have been in common use for a long time are known as the conventional energy.
  • The two main conventional energy sources are:
    • Firewood
    • Fossil fuels

→ Firewood:

  • More than fifty per cent of the energy used by villagers comes from firewood in our country.
  • It is mainly used for cooking and heating.

→ Fossil Fuel:

  • Fossil fuels are the fuel which are formed by the natural processes.
  • For millions of years, remains of plants and animals which were buried under the earth got converted by the heat and pressure into fossil fuels.
  • Fossil fuel such as coal, petroleum and natural gas are the main sources of conventional energy.

→ Coal:

  • Electricity from coal is known as thermal power.
  • Coal is also known as Buried Sunshine because the coal which we are using today was formed millions of years ago when giant ferns and swamps got buried under the layers of earth.
  • In India, the coal producing areas are Raniganj, Jharia, Dhanbad and Bokaro in Jharkhand.
  • The leading coal producers of the world are China, USA, Germany, Russia, South Africa and France.

→ Petroleum:

  • A thick black liquid is known as Petroleum. Since they are very valuable, petroleum and its derivatives are called Black Gold.
  • Petroleum is found between the layers of rocks and is drilled from oil fields which is located in off-shore and coastal areas. Then sent to refineries which process the crude oil and produce a variety of products such as diesel, petrol, kerosene, wax, plastics and lubricants.
  • The chief petroleum producing countries are Iran, Iraq, Saudi Arabia and Qatar.
  • The leading producers in India are Digboi in Assam, Bombay High in Mumbai and the deltas of Krishna and Godavari rivers.

→ Natural Gas:

  • Natural gas is found with petroleum deposits and is released when crude oil is brought to the surface. Very few countries in the world have sufficient amount of natural gas reserves of their own.
  • Russia, Norway, UK and the Netherlands are the major producers of natural gas. In India, Jaisalmer, Krishna Godavari delta, Tripura and some areas off shore in Mumbai have natural gas resources.
  • The consumption of fossil fuels has increased which led to their depletion at an alarming rate. The toxic and poisonous pollutants released from burning these fuels are major cause for concern.

JAC Class 8 Social Science Notes Geography Chapter 3 Mineral and Power Resources

→ Hydel Power:

  • Rainwater or river water stored in dams produce electricity by a specific method. This electricity is known as Hydro electricity.
  • The water discharged after the generation of electricity is used for irrigation. The world’s electricity is produced by hydel power is one fourth.
  • Paraguay, Norway, Brazil, and China are the leading producers of hydroelectricity.
  • In India, some important hydel power stations are Bhakra Nangal, Gandhi Sagar, Nagarjun Sagar and Damodar valley projects.

→ Non-Conventional Sources of Energy:
There is need for using non-conventional sources such as solar energy, wind energy, tidal energy which are renewable because the increasing use of fossil fuels is leading to its shortage.

→ Solar Energy:

  • Solar energy trapped from the sun can be used in solar cells to produce electricity. Many of these cells are joined into solar panels to generate power for heating and lighting purpose.
  • Solar energy is also used in solar heaters, solar cookers, solar dryers and traffic signals.

→ Wind Energy:

  • Wind mills have been used for grinding grain and lifting water since ancient times. In modem time, the wind mills with high speed winds rotate the wind mill which is connected to a generator to produce electricity.
  • Windfarms are found in Netherlands, Germany, Denmark, UK, USA and Spain which are known for their wind energy production.

→ Nuclear Power:

  • Nuclear power is obtained from energy stored in the nuclei of atoms of naturally occurring radioactive elements such as uranium and thorium.
  • Rajasthan and Jharkhand have large deposits of Uranium. Thorium is found in large quantities in the Monozite sands of Kerala.
  • In India, the nuclear power stations are situated in Kalpakkam in Tamilnadu, Tarapur in Maharashtra, Ranapratap Sagar near Kota in Rajasthan, Narora in Uttar Pradesh and Kaiga in Karnataka.

→ Geothermal Energy:

  • Geothermal energy is the heat energy which is obtained from the earth. This heat energy can be used to generate power.
  • USA has the world’s largest geothermal power plants followed by New Zealand, Iceland, Philippines and Central America. In India, geothermal plants are situated in Manikaran in Himachal Pradesh and Puga Valley in Ladakh.

→ Tidal Energy:

  • Tidal energy is the energy generated from tides.
  • Electricity is produced during high tide the energy of the tides is used to turn the turbine installed in the dam.
  • Russia, France and the Gulf of Kachchh in India have huge tidal mill farms.

JAC Class 8 Social Science Notes Geography Chapter 3 Mineral and Power Resources

→ Biogas:

  • Biogas is a gaseous fuel made of organic waste such as dead plant and animal material, animal dung and kitchen waste. These wastes are converted into the gaseous fuel.
  • The organic waste is decomposed by bacteria in biogas digesters to emit biogas which is a mixture of methane and carbon dioxide.

JAC Class 8 Social Science Notes