Class 10SST Ncert Minerals and Resources Notes and Solutions

Amend Education Academy

Mineral Resources

Minerals: A homogenous, naturally occurring substance with definable internal structure is called mineral.

Types of Minerals

Metallic

Ferrous (containing iron): Iron ore, manganese, nickel, cobalt, etc.

Non-ferrous: Copper, lead, tin, bauxite, etc.

Precious: Gold, silver, platinum, etc.

Non-metallic: Mica, salt, potash, sulphur, granite, limestone, marble, sandstone, etc.

Energy Minerals: Coal, petroleum and natural gas

Mode of occurrence of minerals:

In igneous and metamorphic rocks: The smaller occurrences are called veins and the larger occurrences are called lodes. They are usually formed when minerals in liquid/molten and gaseous forms are forced upwards through cavities towards the earth’s surface. Examples: tin, copper, zinc, lead, etc.

In sedimentary rocks: In these rocks, minerals occur in beds or layers. Coal, iron ore, gypsum, potash salt and sodium salt are the minerals found in sedimentary rocks.

By decomposition of surface rocks: Decomposition of surface rocks and removal of soluble constituents leaves a residual mass of weathered material which contains ores. Bauxite is formed in this way.

As alluvial deposits: These minerals are found in sands of valley floors and the base of hills. These deposits are called placer deposits. They generally contain those minerals which are not corroded by water. Examples; gold, silver, tin, platinum, etc.

In ocean water: Most of the minerals in ocean water are too widely diffused to be of economic importance. But common salt, magnesium and bromine are mainly derived from ocean waters.

Iron Ore

India is rich in good quality iron ores. Magnetite is the finest iron ore with a very high content of iron upto 70%. This iron ore is valuable for the electrical industry because of its excellent magnetic properties. Hematite ore is the most important industrial iron ore; in terms of usage. The iron content of hematite is 50-60%.

Fig: Iron ore in India

Major Iron Ore Belts in India

Orissa Jharkhand Belt: Badampahar mines in the Mayurbhanj and Kendujhar districts of Orissa have high grade hematite ore. Additionally, hematite iron ore is mined in Gua and Noamundi in Singhbhum district of Jharkhand.

Durg Bastar Chandrapur Betl: This belt lies in Chhattisgarh and Maharashtra. The Bailadila range of hills in the Bastar district of Chhattisgarh have very high grade hematite ore. This hilly range has 14 deposits of super high grade hematite ore. Iron from these mines is exported to Japan and South Korea via Vishakapatnam port.

Bellary Chitradurga Chikmaglur Tumkur Belt: This belt lies in Karnataka. The Kudremukh mines located in the Western Ghats are a 100 percent export unit. The ore from these mines is transported as slurry through a pipeline to a port near Mangalore.

Maharashtra Goa Belt: This belt inculdes the state of Goa and Ratnagiri district of Maharashtra. The ores in these mines are not of very high quality. They are exported through Marmagao port.

Manganese

Manganese is mainly used in the manufacturing of steel and ferro-manganese alloy. It is also used in making bleaching powder, insecticides and paints.

Fig: Manganese ore in India

Copper

Copper is mainly used in electrical cables, electronics and chemical industries. The Balaghat mines in Madhya Pradesh produce 52% of India’s copper. Rajasthan is the next leading producer with about 48% share. Copper is also produced in the Singhbhum district of Jharkhand.

Aluminium

Aluminium is lightweight yet strong and hence is used in a variety of applications. Amarkantak plateau, Maikal hills and the plateau region of Bilaspur-Katni are the main areas of bauxite deposits. Orissa is the leading producer of bauxite in India with 45% share. Panchpatmali in Koraput district is the most important centre of bauxite deposit in Orissa.

Mica

Mica is a mineral which is made up of a series of plates or leaves. The mica sheets can be so thin that a thousand of them can be layered into a few centimetre thick mica sheet. Mica has excellent di-electric strength, low power loss factor, insulating properties and resistance to high voltage. Mica is widely used in electric and electronic industries.

Mica deposits are found in the northern edge of the Chota Nagpur plateau. Koderma-Gaya-Hazaribagh belt of Jharkhand is the leading producer of mica. Ajmer in Rajasthan and Nellore in Andhra Pradesh are the other important producers of mica.

Hazards of Mining

Mining is a hazaradous industry; both for the workers and for the residents. The Miners have to work under tough conditions where no natural light is available. There is always a risk of collapse of mine roof, inundation with water and fire. The areas around mines face the problem of too much dust from the mines. Slurry from mines damages the roads and the farmland. Houses and clothes become dirty more often than in other areas. Miners are at great risk of getting afflicted with pulmonary disorders. Cases of respiratory tract diseases are very high in mining areas.

Conservation of Minerals

It takes millions of years for the formation of minerals. Compared to the present rate of consumption, the replenishment rate of minerals is very slow. Hence, mineral resources are finite and non-renewable. Due to this, it is important that we conserve the mineral resources.

Energy Resources

Conventional Energy Resources: Firewood, cattle dung cake, coal, petroleum, natural gas and electricity (both hydel and thermal)

Non-conventional Energy Resources: Solar, wind, tidal, geothermal, biogas and atomic energy.

Firewood and cattle dung cake: As per estimates, more than 70% of energy need in rural households is met by firewood and cattle dung cake. A decreasing forest area is making it difficult to use firewood. Dung cake can be put to better use in the form of manure and hence its use should also be discouraged.

Coal:

India is highly dependent on coal for meeting its commercial energy requirements. Depending on the degree of compression during its formation, there are varieties of coal.

Lignite: It is a low grade brown coal. It is soft and has high moisture content. Neyveli in Tamil Nadu has the main reserves of lignite coal. This type of coal is used for electricity generation.

Bituminous coal: Coal which was formed because of increased temperature and was buried very deep is called bituminous coal. This is the most popular coal for commercial use. High grade bituminous coal is ideal for use in metallurgy.

Anthracite coal: This is the highest quality hard coal.

In India, coal occurs in rock series of two main geological ages. The Gondwana coal was formed over 200 million years ago. The tertiary deposits are about 55 million years old. The major sources of Gondwana coal are located in the Damodar valley (West Bengal-Jharkhan). In this belt; Jharia, Raniganj and Bokaro are important coalfields. Coal deposits are also present in the Godavari, Mahanadi, Son and Wardha valleys.

Tertiary coal is found in the north-eastern states of Meghalaya, Assam, Arunachal Pradesh and Nagaland.

Petroleum

After coal, the next major energy resource in India is petroleum. Petroleum is a major source of fuel for various uses. Petroleum also provides raw materials for various manufacturing industries; like plastic, textiles, pharmaceuticals, etc.

Most of the petroleum in India occurs in anticlines and fault traps in the rock formations of the tertiary age. The oil bearing layer is a porous limestone or sandstone through which oil may flow. The intervening non-porous layers prevent the oil from rising or sinking. Petroleum is also found in fault traps between porous and non-porous rocks. Gas usually occurs above the oil because it is lighter than oil.

Mumbai High produces about 63% of India’s petroleum, Gujarat produces 18% and Assam 13%. Ankeleshwar is the most important oil field in Gujarat. Assam is the oldest oil producing state of India. Important oil fields of Assam are Digboi, Naharkatiya and Moran-Hugrijan.

Natural Gas

Natural gas is found alongwith or without petroleum. It is used as fuel and also as industrial raw material. Large reserves of natural gas have been discovered in the Krishna-Godavari Basin. Gulf of Cambay, Mumbai High and Andaman Nicobar islands are also important areas with large reserves of natural gas.

The 1700 km long Hazira-Vijaipur-Jagdishpur pipeline links Mumbai High and Bassein with the fertiliser, power and industrial complexes in western and northern India. Natural gas is mainly used by the fertiliser and power industries. Now-a-days, use of CNG (Compressed Natural Gas) is increasing as vehicle fuel in the country.

Electricity

Electricity is generated mainly by two methods; by running water which drives hydro turbines and by burning other fuels like coal, petroleum and natural gas to drive turbines. Bhakra Nangal, Damodar Valley Corporation, Kopili Hydel Project, etc. are major hydroelectric producers in the country. At present, there are over 300 thermal power stations in India.

Non-conventional Sources of Energy

Nuclear Energy: Nuclear energy is obtained by altering the structure of atom. When the structure of an atom is altered, too much energy is released in the form of heat. This heat is utilised to generate electric power. Uranium and Thorium are used for generating atomic power. These minerals are available in Jharkhand and the Aravalli ranges of Rajasthan. The Monazite sand of Kerala is also rich in Thorium.

Solar Energy: Photovoltaic technology is used to convert solar energy into electricity. The largest solar plant of India is located at Madhapur near Bhuj. Solar energy holds great promises for the future. It can help in minimizing the dependence on firewood and animal dung cakes in rural areas. This will also help in conservation of fossil fuels.

Wind Power: India now ranks as a “Wind Super Power” in the world. The wind farm cluster in Tamil Nadu (from Nagarcoil to Madurai) is the largest cluster in India. Andhra Pradesh, Karnataka, Gujarat, Kerala, Maharashtra and Lakshadweep are also important centres of wind power production.

Biogas: Biogas can be produced from shrubs, farm waste, and animal and human waste. Biogas is more efficient than kerosene, dung cake and charcoal. Biogas plants can be set up at municipal, cooperative and individual levels. The gobar gas plants provide energy and also manure.

Tidal Energy: Floodgate dams are built across inlets. The water flows into the inlet during high tide and gets trapped when the gate is closed. Once the tide recedes, the gates are opened so that water can flow back to the sea. The flow of water is used to run the turbine to generate electricity. A 900 mw tidal energy power plant is set up by the National Hydropower Corporation in the Gulf of Kuchchh.

Geo Thermal Energy: We know that the inside of the earth is very hot. At some places, this heat is released on the surface through fissures. Groundwater in such areas becomes hot and rises up in the form of steam. This steam is used to drive turbines. Two experimental projects have been set up in India to harness geothermal energy. They are; the Parvati valley near Manikarn in Himachal Pradesh and the Puga Valley in Ladakh.

Mineral Resources: NCERT Solution

Distinguish between the following in not more than 30 words.  Ferrous and non-ferrous minerals
Answer: Metallic minerals which contain iron are called ferrous minerals, e.g. iron ore, manganese, nickel, cobalt, etc. On the other hand, metallic minerals which do not contain iron are called non-ferrous minerals, e.g. copper, bauxite, tin, etc.

Conventional and non-conventional sources of energy
Answer: Sources of energy which have been in use since a long time are called conventional sources of energy, e.g. coal, firewood, petroleum, hydel energy, etc. Sources of energy which have come into use recently are called non-conventional sources of energy, e.g. solar energy, wind energy, nuclear energy, etc.

What is a mineral?
Answer: A homogenous, naturally occurring substance with definable internal structure is called mineral.

How are minerals formed in igneous and metamorphic rocks?
Answer: In igneous and metamorphic rocks: The smaller occurrences are called veins and the larger occurrences are called lodes. They are usually formed when minerals in liquid/molten and gaseous forms are forced upwards through cavities towards the earth’s surface. Examples: tin, copper, zinc, lead, etc.

Why do we need to conserve mineral resources?
Answer: It takes millions of years for the formation of minerals. Compared to the present rate of consumption, the replenishment rate of minerals is very slow. Hence, mineral resources are finite and non-renewable. Due to this, it is important that we conserve the mineral resources.

Describe the distribution of coal in India.
Answer: In India, coal occurs in rock series of two main geological ages. The Gondwana coal was formed over 200 million years ago. The tertiary deposits are about 55 million years old. The major sources of Gondwana coal are located in the Damodar valley (West Bengal-Jharkhan). In this belt, Jharia, Raniganj and Bokaro are important coalfields. Coal deposits are also present in the Godavari, Mahanadi, Son and Wardha valleys. Tertiary coal is found in the north-eastern states of Meghalaya, Assam, Arunachal Pradesh and Nagaland.

Why do you think that solar energy has a bright future in India?
Answer: Solar energy holds great promises for the future. It can help in minimizing the dependence on firewood and animal dung cakes in rural areas. This will also help in conservation of fossil fuels.

Class 8 SCIENCE NCERT NOTES SOUND

Sound

Sound is very important for our life. It is the sound that helps us to communicate with each other.

Production of sound –

Sound is produced because of vibration of an object. In other words, a vibrating object produces sound.

Example –

When a table is beaten, it starts vibrating and produces sound.

When a drum is beaten, it starts vibrating and produces sound.

When a stretched rubber band is struck, it starts vibrating and produces sound.

Musical instruments produce different types of sound because of vibration. For example; a flute produce sound because of vibration in its air column, a guitar produces sound because of vibration of its string, a drum produces sound because of vibration of its diaphragm.

Sound Produced by Human:

A human being produces sound because of vibration of his voice box. The voice box is also known as larynx. Larynx is situated at the upper end of windpipe. There are two stretched membranes attached in larynx; with a narrow slit between them. When air passes through those stretched membranes they produce different types of sound with different combinations of stretching.

Sound needs a medium to propagate:

The traveling of sound is called propagation of sound. Sound cannot propagate in the absence of a medium. The place where there is no air or air is removed, is called vacuum. Sound does not propagate (travels) through vacuum.

Sound travels through solid, liquid and gas.

We usually hear sound which comes to us through air.

Aquatic animals communicate as sound travels through water also.

We hear the sound through ear

The external ear works like a funnel. Due to its unique shape, sound waves are concentrated once they enter through the external ears. Then the sound waves reach the ear drum or tympanum. The tympanum is like a stretched membrane; which vibrates when sound waves strike it. From the ear drum, sound waves reach inner ear; through middle ear. From inner ear, sound waves are sent to the brain via auditory nerve. The brain interprets these signals and we hear the sound.

Amplitude, Time Period and Frequency of a Sound

Sound travels in the form of wave. When a pebble is dropped in pond water, it produces ripples in water. The ripple is called wave. Sound travels producing similar waves.

Amplitude and frequency are two important characters of sound. Sounds produced by different object are differentiated by amplitude and frequency of sound.

Amplitude – The distance from normal to peak is called amplitude. Since, sound travels in the form of wave, so sound has amplitude.

Frequency: The number of vibrations or oscillations per second is called frequency.

Frequency is expressed in hertz.

If an object oscillates or vibrates 40 times in 1 second, then its frequency will be equal to 40 hertz.

Time period - Time required to produce one complete oscillation is called time period.

Loudness and Pitch

Loudness of sound depends on the amplitude of the sound wave. Greater amplitude produces louder sound and smaller amplitude produces feeble sound.

Loudness of sound is measured in decibel (dB). Loudness of some types of sound is given here in decibel.

Shrillness or pitch

Frequency of a sound determines the shrillness or pitch of the sound. Shrillness or pitch increases with increase in frequency of sound. Sound with greater frequency is shriller and has higher pitch. Sound with lower frequency is less shrill and of lower pitch.

Examples:

Children and women produce sound of high frequency and their sound is shriller and of higher pitch. On the other hand, an adult male produces sound of lower frequency and his sound is less shrill and has lower pitch.

A drum produces sound of lower frequency which is less shrill and has lower pitch, while a whistle produces sound of higher frequency which is shriller and is of higher pitch.

A lion produces a sound of lower frequency which is less shrill and has lower pitch, while a bird produces sound of high frequency which is shriller and has higher pitch. However, sound of lion is louder than the sound of a bird.

Audible and Inaudible Sound

Sounds with frequency between 20 Hz to 20,000 Hz are called audible sound. The hearing range of human beings is between 20 hertz to 20,000 hertz.

Sound with frequency below 20 hertz and above 20,000 hertz is called sound of inaudible range. Humans cannot hear the sound of inaudible range.

Many animals, such as dogs, cats, etc. can hear the sound with frequency above 20,000 hertz.

Noise and Music

Sound that appears unpleasant to us is called noise, such as sound of horn, sound near the site of construction work, sound of aeroplane, etc.

Sound that appears pleasant to our ear is called musical sound, such as sound of musical instrument, song of a good singer, etc.

Noise Pollution

Loud and excessive sound is unbearable to our ears, and is called noise. Unwanted and excessive sound in our environment creates noise pollution. Sounds of crackers, factories, vehicles, desert coolers, air conditioners, aeroplane, transistors or television with high volume, loudspeakers, etc. create sound pollution.

Problems due to Noise Pollution:

Noise pollution can create many types of health related problems, such as lack of sleep (insomnia), hypertension, loss of hearing, anxiety, etc. Sound above 80 dB is very painful to hear.

A person who is exposed to loud sound continuously may get permanent or temporary loss of hearing (impairment of hearing).

Measure to Limit Noise Pollution

Noise pollution can be limited or controlled by controlling the noise coming from source. Noise pollution can be limited by taking following measures:

TV or radio should be played at low volume.

By installing high quality silencer in vehicles.

Minimum use of vehicle horns.

Plantation of trees along the road sides and around buildings. Trees absorb sound.

Awareness campaign to make people aware; about the harmful effects of noise pollution and measures to control noise pollution.

Question: Lightning and thunder take place in the sky at the same time and at the same distance from us. Lightning is seen earlier and thunder is heard later. Can you explain?

Answer: We know that the speed of light much more than the speed of sound. Due to this, light reaches to us faster than sound. Hence, during lightning we see the streak of light earlier than hearing the sound of thunder.

Class 10 sst NCERT NOTES AND SOLUTIONS Popular Struggle and Movement class 10

Popular Struggle and Movement class 10

Mobilisation and Organisations:

Political Parties: Some organizations directly participate in the democratic process. These organizations are called political parties. They contest elections and aim to form government.

Pressure Groups: Some organizations indirectly participate in the democratic process. These organizations are called interest groups or pressure groups.

Pressure Groups and Movements

Pressure groups do not aim to form or run the government. When people of common occupation, interest aspirations or opinions come together; in order to achieve a common objective; they form pressure groups. These pressure groups carry on popular movements in order to meet their objectives. It is not necessary that all the pressure groups go on creating popular movements rather many of them work in closely knit groups.
Some examples of popular movements in India are: Narmada Bachao Andolan, Movement for Right to Information, Anti-liquor Movement, Women’s Movement, Environmental Movement.

Sectional Interest Groups and Public Interest Groups

Sectional Interest Groups: Usually interest groups seek to promote the interests of a particular section or group of society. Trade unions, business associations and professional (lawyers, doctors, teachers, etc.) bodies are some examples of this type. They are sectional because they represent a section of society: workers, employees, businesspersons, industrialists, followers of a religion, caste group, etc. Their principal concern is the betterment and well being of their members, not society in general.
Public Interest Groups: These second type of groups are called promotional groups or public interest groups. They promote collective rather than selective good. They aim to help groups other than their own members. Trade Unions, Students’ Union, Ex-Armymen Association, etc. are examples of public interest groups.

Pressure Groups' and Movements' Influence on Politics:

Public Sympathy: They try to gain public support and sympathy for their goals and their activity. For this, they carry information campaigns, organise meetings, file petitions, etc. Many of them also try to influence the media to get more attention.
Protest Activity: They often organise protest activity. Protest activities include like strikes or disrupting government programmes. Strikes and disruptions are utilized to pressurize the government to take note of their demand.
Lobbying: Business groups often employ professional lobbyists or sponsor expensive advertisements. Some persons from pressure groups or movement groups may participate in official bodies and committees that offer advice to the government. Some professional bodies; like ASSOCHAM and NASSCOM are examples of such groups.

Influence on Political Parties: The interest groups and movement try to influence political parties. They usually have a particular political ideology and political position on major issues. A pressure group can be directly or indirectly linked to a political party.

Critical Analysis of Influence of Pressure Groups:

• Many arguments are forwarded against pressure groups. Many thinkers say that since a pressure group champions the cause of a small section of society; so it should be viewed with caution. Democracy is not about narrow interests of a particular section but a larger interest of the overall society. Unlike political parties, a pressure group is not answerable to the people and hence they may not have a broader perspective in mind. There can be many examples of pressure groups which are sponsored by powerful business lobbyists or by some international agencies. They should be treated with caution.
• Many people argue in favour of pressure groups. They say that putting pressure on the government is always positive for the deepening of democracy. The political parties often tend to forget the real concerns of people; in their pursuit of power. The role of pressure group is to awaken them from their slumber.
• It can be said that pressure groups play the balancing role among various political ideologies and usually highlight the real concerns of people.

Answer the following questions:

• In what ways do pressure groups and movements exert influence on politics?
  Answer: Pressure groups and movements exert influence on politics in following ways:
• By gaining public support and sympathy for their cause
• By staging protest activities to pressurize the government
• By making lobbies
• Describe the forms of relationship between pressure groups and political parties?
  Answer: Generally, there is no direct relationship between pressure groups and political parties. They usually take positions which are opposite to each other. But dialogue and negotiations do exist between them. Many new leaders of the political parties come from a pressure group.
• Explain how the activities of pressure groups are useful in the functioning of a democratic government.
  Answer: The activities or pressure groups are useful in deepening the democracy. They help in raising the voice of ordinary citizens against powerful lobbyists from the business. Their actions and tactics may seem to be disruptive but they create a balance between the powerful ruling and business classes and the powerless common man.
• What is a pressure group? Give a few examples.
  Answer: Organizations which influence the policies of the government are pressure groups. A pressure group is different to a political party because it is not directly answerable to the people. Moreover, the pressure group does not control or stake a share in political power. Narmada Bachao Andolan, Trade Unions, Lawyers’ Association, etc. are examples of pressure groups
• What is the difference between a pressure group and a political party?
  Answer: A political party is directly answerable to the people, while a pressure group is not. A political party either controls power or stakes a claim in power, while a pressure group does not do so.
• Organisations that undertake activities to promote the interests of specific social sections such as workers, employees, teachers, and lawyers are called _____________________ groups.
  Answer: Sectional Interest Groups
• Match List I (organisations and struggles) with List II and select the correct answer using the codes given below the lists:
  Answer: