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Extra Questions for Class 9th: Ch 6 Democratic Rights Civics

October 16, 2018, 9:38 pm
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Extra Questions for Class 9th: Ch 6 Democratic Rights Social Studies (S.St) Important Questions Answer Included

Very Short Answer Questions (VSAQs): 

1. What was the reason given by America for imprisoning people at Guantanamo Bay?

Answer 

America considered them as enemies and linked them to the attack on New York on 11th September 2001.

2. Which body exposed to the world that prisoners at Guantanamo Bay were being tortured in ways that violated the US laws?

Answer 

Amnesty International.

3. What are rights?

Answer 

Rights are claims of a person over other fellow beings, over the society and over the government.

4. What can be done in case of infringement of the rights in a democracy?

Answer 

They can approach courts to protect their rights.

5. Where do we find the basic rights in most democracies?

Answer 

In most democracies, the basic rights of the citizens are written down in the constitution.

6. Which Fundamental Right allows importing religious instructions in minority educational institutions?

Answer

‘Cultural and Educational Right’. 

7. Which Fundamental Right was considered as the ”The Soul of Constitution” by Dr. B.R. Ambedkar?

Answer 

‘Right to Constitutional Remedies‘.

Short Answer Questions (SAQs):

1. Why are rights guaranteed by the Indian Constitution called Fundamental Rights?

Answer

• These rights are essential for the overall development of the citizens.
• These are enforceable in the courts of law. 
• These have been given to all the citizens by the Indian Constitution and the government cannot abolish them.

2. Mention the restrictions that can be imposed on various forms of freedoms granted by the Indian Constitution. 

Answer

The following restrictions can be imposed on various forms of freedoms granted by the constitution:
• Freedom of speech and expression– reasonable restrictions can be imposed on this freedom.
• Restriction on freedom to hold meetings, processions, rallies and demonstrations and reasonable restrictions can be put in the interest of public order. 
• Restriction on freedom to form associations and unions can be imposed in the interest of public order, morality or sovereignty or integrity of India. 

3. ”Secularism is based on the idea that the state is concerned only with relations among human beings.” Explain. 

Answer

• As a secular nation, every citizen of India has the right to freedom of religion i.e. ”liberty of thought, belief, faith and worship”.
• We have the freedom to run religious affairs. 
• The Indian Constitution firmly states that all religions are equal before law

4. Mention any three rights of a detained person. 

Answer

• To be informed of the reason of arrest and detention. 
• To be produced before the nearest magistrate within 24 hours of arrest.
• Right to consult a lawyer or engage a lawyer for his defence. 

5. “Secularism is based on the idea that the state is concerned only with relations among human beings”. Explain. 

Answer

• As a secular nation, every citizen of India has the right to freedom of religion i.e., “Liberty of thought, belief, faith and worship”.
• We have the freedom to run religious affairs. 
• Indian Constitution firmly states that all religions are equal before law. 

Long Answer Questions (LAQs):

1. What is the relationship between the citizens and the Government of Saudi Arabia as far as human rights are concerned? State in five points. 
OR 
What is the position of the citizens in Saudi Arabia with respect to their government? 

Answer

• Saudi Arabia is ruled by a hereditary king and the people have no role in electing or changing their rulers.
• The king selects the legislature as well as the executives. He appoints the judges and can change any of their decisions. 
• Citizens cannot form political parties or any political organizations. Media cannot report anything that the monarch does not like. 
• Every citizen is required to be Muslim.
• Non-Muslim residents can follow their religion in private, but not in public.

2. “The claims of the citizens should be such that it can be made available to the others also.” Explain. Also, summarise the important characteristics of rights.

Answer

The sentence means that the claims of the citizens should be reasonable. They should be such that can be made available to others in equal manner. Thus, a right comes with an obligation to respect other’s rights. 
Characteristics of rights: 
• Rights are necessary for the very sustenance of a democracy.
• Rights protect minorities from the oppression of majority.
• Rights are guarantees which can be used when things go wrong.

3. Describe the features of Right against Exploitation. 
OR 
Describe the various provisions given under the Right against Exploitation. 

Answer

Once the right to liberty and equality is granted, it follows that every citizen has a right not to be exploited.
• The Indian Constitution prohibits trafficking in human beings. Trafficking here means buying and selling of human beings, usually women for immoral purposes. Our constitution also prohibits forced labour or ‘beggar’ in any form. Beggar is a practice where the worker is forced to work without any remuneration. 
• The Indian Constitution also prohibits child labour. No one can employ children below fourteen years to work in any factory or mine or in any other hazardous work place. 

High Order Thinking Skills (HOTS):

1. Can a person change his religion? Support your answer with the concerned Fundamental Right.

Answer

Yes, a person can change his religion. He/She is free to change religion on his or her own will. 
• Right to Freedom of Religion states that in India every person has a right to profess, practice and propagate the religion he or she believes in.
• The right to propagate one's religion however does not mean that a person has right to compel another person to convert into his religion by force, fraud, inducement or allurement. 
• Every religious group is free to manage its religious affairs.
•  The government cannot compel any person to pay any taxes for the propagation of any particular religion or religious institution. 
• There shall be no religious instruction in the government educational institutions. In educational institutions managed by private bodies, no person shall be compelled to take part in any religious activities.


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Extra Questions for Class 10th: Ch 3 Water Resources Geography

October 17, 2018, 12:24 am
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Extra Questions for Class 10th: Ch 3 Water Resources Social Studies (S.St) Important Questions Answer Included

Very Short Answer Questions (VSAQs): 

1. Name any one river valley project which has significantly contributed to the loss of forest?

Answer 

Sardar Sarovar Dam

2. Name two Environmental movements which were against the multi-purpose projects.

Answer 

Narmada Bachao Andolan and Tehri Dam Andolan.

3. What percentage of the total volume of world’s water is estimated to exist as oceans?

Answer 

96.5%.

4. Who proclaimed dams as the temple of modern India?

Answer 

Jawaharlal Nehru.

5. Which river is known as the ‘River of Sorrow’?

Answer 

Damodar River.

6. On which river ‘Bhakhra Nangal Dam’ has been constructed?

Answer

River Satluj.

7. On which river has the Hirakud Dam been constructed?

Answer 

River Mahanadi.

8. What is a Dam?

Answer 

A dam is a barrier across flowing water.

Short Answer Questions (SAQs):

1. Mention any four main objectives of multipurpose river valley projects. Name any two Multipurpose Projects of India.

Answer 

Four main objectives of multipurpose river valley projects are-
• For irrigational activities.
• To generate hydroelectricity.
• To control flood.
• For recreation
Two multipurpose projects are Bhakhra nangal project and Hirakud project. 

2. Why did Jawaharlal Nehru proclaim the dams as the “temples of modern India”? Explain any three reasons.

Answer 

Jawaharlal Nehru proclaimed the dams as the “temples of modern India” because:
• It would integrate development of agriculture and the village economy.
• Provide hydroelectricity for houses and industries.
• They eliminate or reduce flooding.

3. What does the Qualitative scarcity of water mean?

Answer 

The qualitative scarcity of water means bad Quality of water due to industrial waste and impurities due to chemical fertilizers and pesticides used in agriculture which makes water hazardous for human use.

Long Answer Questions (LAQs):

1. How have intensive industrialization and urbanization posed a great pressure on existing fresh water resources in India. Explain.

Answer

• Large scale industrialisation and urbanisation have posed a great pressure on existing fresh water resources as many multinational companies are being set up in India who are the heavy consumers of water for processing, discharge of effluents and as an energy resource.
• Hydroelectricity produced for industrial units have not only posed a great threat to the availability of fresh water resources but also contributed to bad quality of water with large growing number of urban centres and population.
• Modern lifestyle of the urban people has created more demand for water both for domestic purposes and increased consumption of energy.
• In housing colonies to meet the needs of population, water resources are over-exploited resulting in depletion of ground water resources.
• Fresh water needs to be protected from industrial pollution and wastage of water in cities.

2. Explain any three reasons responsible for water scarcity in India?
OR
Water is available in abundance in India even then scarcity of water is experienced in major parts of the country. Explain it with four examples.

Answer

• The availability of water resources varies over space and time, mainly due to the variations in seasonal and annual precipitation.
• Over-exploitation, excessive use and unequal access to water among different social groups.
• Water scarcity may be an outcome of large and growing population and consequent greater demands for water. A large population means more water to produce more food. Hence, to facilitate higher food-grain production, water resources are being over exploited to expand irrigated areas for dry-season agriculture.
• Most farmers have their own wells and tubewells in their farms for irrigation to increase their production. But it may lead to falling groundwater levels, adversely affecting water availability and food security of the people. Thus, inspite of abundant water there is water scarcity.



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Extra Questions for Class 10th: Ch 4 Agriculture Geography

October 17, 2018, 1:27 am
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Extra Questions for Class 10th: Ch 4 Agriculture Social Studies (S.St) Important Questions Answer Included

Very Short Answer Questions (VSAQs): 

1. By which name is specialized cultivation of fruits and vegetables known?

Answer

Horticulture.

2. Describe ‘Jhumming cultivation’ in one sentence.

Answer 

‘Slash and burn’ agriculture.

3. Which state is the leading coffee producer state in India?

Answer 

Karnataka.

4. India is the largest producer as well as consumer of which agricultural product in the world?

Answer

Pulses.

5. In which country the ‘slash and burn’ agriculture is known as ‘Roca’?

Answer 

Brazil.

6. Hoe, dao, digging sticks are associated with which type of farming?

Answer 

Primitive subsistence farming.

7. Which crop are grown with the onset of monsoons and are harvested in the month of September and October?

Answer 

Kharif

8. Which crop is the major crop of rabi?

Answer 

Wheat.

Short Answer Questions (SAQs):

1. Which are the two main cropping seasons in India? Mention their growing and harvesting periods.

Answer 

The two main cropping seasons are Rabi and Kharif: 
• Rabi crops are sown in winter from October to December and harvested in summer from April to June. 
• Kharif crops are sown with the onset of monsoon in different parts of the country and harvested in September-October.

2. What are the growing conditions required for the main staple food crop of India? Mention the main growing regions.

Answer

Growing conditions required for rice: 
• High temperature (above 25°C required. It is a Kharif crop. 
• High humidity with annual rainfall above 100 cm. 
• Main growing regions are northern plains, north-eastern India, Costal areas, deltaic plains and river valleys.

3. Explain any two geographical conditions required for the cultivation of pulses. Name any two important pulses producing states.
OR
Why the pulses are mostly grown in rotation with other crops? Name any two major pulse producing states?

Answer

Pulses are mostly grown in rotation with other crops because:
• Pulses need less moisture and survive even in dry conditions. 
• Being leguminous crops, all these crops help in restoring soil fertility by fixing nitrogen from the air.
• Major pulse producing states are Madhya Pradesh and Uttar Pradesh.

Long Answer Questions (LAQs):

1. Describe the institutional and technical changes introduced in the field of agriculture in India in the recent years.

Answer
• Land reforms: Collectivisation, consolidation of holdings, cooperation and abolition of zamindari.
• Agricultural reforms: Green revolution and White revolution. 
• Land development programmes: Provision for crop insurance against drought, flood, cyclone etc., establishment of Grameen banks, Cooperative societies and banks for providing loans.
• Issuing of Kissan Credit Card and Personal Accident Insurance Scheme, etc.
• Special weather bulletins and agricultural programmes for farmers on radio and TV.

2. Define plantation agriculture. Explain any four characteristics of plantation agriculture.

Answer
Plantation Agriculture: It is a type of commercial farming practised in tropical and sub-tropical regions. It was introduced by the British in India.
 Characteristics: 
• A single crop is grown over large area. 
• It is capital intensive and done with migrant labour.
• All produce is used as raw material in industries such as tea, coffee, rubber, sugarcane, banana, etc.
• Plantation has interface of agriculture and industry both.

3. Explain Rubber cultivation in India under the following heads: 
(i) Importance 
(ii) Geographical conditions 
(iii) Producing states

Answer
(i) Importance: 
Many industries depend upon Rubber as their raw material especially transport industry. 
(ii) Geographical condition
• It is an equatorial crop, but under special conditions it is also grown in tropical and subtropical areas. 
• It requires moist and humid climate with rainfall of more than 200 cm and temperature above 25°C. 
(iii) Rubber producing states are Kerala, Tamil Nadu, Karnataka, Andaman and Nicobar Islands and Garo hills of Meghalaya.



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Extra Questions for Class 10th: Ch 5 Minerals and Energy Resources Geography

October 17, 2018, 3:21 am
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Extra Questions for Class 10th: Ch 5 Minerals and Energy Resources Social Studies (S.St) Important Questions Answer Included

Very Short Answer Questions (VSAQs): 

1. How do minerals occur in igneous and metamorphic rocks?

Answer 

May occur in cracks, crevices, faults and joints.

2. How do minerals occur in sedimentary rocks?

Answer 

In beds or layers.

3. Name some minerals formed in beds and layers.

Answer 

Coal, and some forms of iron ore.

4. Which rock consists of single mineral only?

Answer 

Limestone.

5. Why are there a wide range of colours, hardness, crystal forms, lustre and density found in minerals?

Answer 

Due to physical and chemical conditions.

6. How does mining affect the health of miners?

Answer 

The dust and the noxious fumes inhaled by the miners makes them vulnerable to pulmonary diseases.

7. What is hematite?

Answer 

Hematite ore is the most important industrial iron ore in terms of the quantity used.

Short Answer Questions (SAQs):

1. How is mining activity hazardous? Explain.

Answer 

The mining activity is injurious to the health of the miners and environment as: 
• The dust and noxious fumes inhaled by miners make them vulnerable to pulmonary diseases. 
• The risk of collapsing mine roofs. 
• Inundation and fires in coalmines are a constant threat to miners.

2. Name the non-metallic mineral which can split easily into thin sheets. Mention its uses.

Answer 

Mica is the non-metallic mineral which can be split easily into thin sheets. Mica is used in: 
• Mica is used in electric and electronic industries due to its excellent di-electric strength, low power loss factor, insulating properties and resistance to high voltage. 
• Plastic industry also uses mica as an extender and filler.

3. What are ‘placer deposits’? Give examples of minerals found in such deposits.

Answer
• Certain minerals may occur as alluvial deposits in sands of valley floors and base of hills. These deposits are called ‘placer deposits’. 
• They generally contain minerals which are not corroded by water. 
• Gold, silver, tin and platinum are examples of some important minerals found in ‘placer deposits’. 

4. Name the mineral ore from which aluminium is extracted? Why is it gaining importance? Give its distribution in India.

Answer 

Bauxite. 
• Aluminium is gaining importance because of its extreme lightness, good conductivity and great malleability. It combines the strength of metals such as Iron. 
• It is mainly found in Amarkantak Plateau, Maikal Hills and the plateau region of Bilaspur-Katni. Koraput district in Odisha has large deposits. Odisha is the largest bauxite producing state. Others are Gujarat, Maharashtra and Jharkhand.

Long Answer Questions (LAQs):

1. Highlight the importance of petroleum. Explain the occurrence of petroleum in India.

Answer 

Importance of Petroleum: 
• Petroleum is the major energy source in India. 
• Provides fuel for heat and lighting. 
• Provides lubricant for machinery. 
• Provides raw material for a number of manufacturing industries. 
• Petroleum refineries act as nodal industry for synthetic, textile, fertilizer and chemical industries.
Its occurrence: 
• Most of the petroleum occurrences in India are associated with anticlines and fault traps. 
• In regions of folding, anticline or domes, it occurs where oil is trapped in the crest of the upfold 
• Petroleum is also found in fault traps between porous and non-porous rocks.

2. Explain the importance of conservation of minerals. Highlight any three measures to conserve them.
OR
Why is conservation of mineral resources essential? Explain any three methods to conserve them.

Answer
Reasons for Conservation: 
• The strong dependence of industry and agriculture upon minerals. 
• The process of mineral formation is slow. 
• They are non-renewable. 
Methods to conserve: 
• Minerals should be used in a planned and sustainable manner. 
• Improved technology needs to be constantly evolved to allow use of low grade ore at low cost. 
• Recycling of metals using scrap metals. 
• Wastage in the mining and processing should be minimised.

High Order Thinking Skills (HOTS):

1. There is an urgent need to develop a sustainable path of energy development. Give two broad measures for it. As concerned citizens, how can you help to conserve energy?

Answer 

Twin planks/measures: 
• Promotion of energy conservation.
• Increased use of renewable energy sources. As concerned citizens we can do our bit by: 
• Using public transport systems instead of individual vehicles. 
• Switching off electricity when not in use. 
• Using power–saving devices. 
• Using non-conventional sources of energy.



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Extra Questions for Class 10th: Ch 6 Manufacturing Industries Geography

October 18, 2018, 2:01 am
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Extra Questions for Class 10th: Ch 6 Manufacturing Industries Social Studies (S.St) Important Questions Answer Included

Very Short Answer Questions (VSAQs): 

1. By which development, the economic strength of the country is measured?

Answer

The development of the manufacturing industries.

2. Why has the ‘National Manufacturing Competitiveness Council’ been Set-up?

Answer

To improve productivity, economist predicts that manufacturing can achieve its target over the next decades.

3. Name three human inputs that control location of industries.

Answer

Human inputs that control location of industries are Labour, market and Transport facilities.

4. What are light industries?

Answer 

Industries that use light raw materials and produce light goods are called light industries.

5. Name four important cotton textile centres of Maharashtra.

Answer 

The cotton textile centres of Maharashtra are Mumbai, Solapur, Pune and Nagpur.

6. Name two most important sugar producing states of India.

Answer 

Uttar Pradesh and Maharashtra.

7. Name three major air pollutants.

Answer 

Air borne dust, smoke and undesirable gases are three major air pollutants.

8. What do you mean agglomeration economies?

Answer 

Many industries tend to come together to make use of the advantages offered by the urban centres known as agglomeration economies.

Short Answer Questions (SAQs):

1. Describe the importance of manufacturing sector in countries like India.
OR
“The economic strength of a country is measured by the development of manufacturing industries”. Justify this statement with examples.

Answer 

• Manufacturing industries help in modernizing agriculture;
• They also reduce the heavy dependence of people on agricultural income by providing them jobs.
• Industrial development reduces unemployment and poverty:
• It also brings down regional disparities.

2. Define the term manufacturing. Classify industries on the basis of source of raw materials used.

Answer

Definition: “Production of goods in large quantities after processing from raw materials to more valuable products is called manufacturing”. Classification:
• Agro-based: Cotton, wool, jute, silk textile, etc.
• Mineral-based: Iron, steel, cement etc.

3. ”Agriculture gives boost to the industrial sector.” Support the statement with arguments.
OR
“Agriculture and industry are not exclusive of each other. They move hand in hand.” Justify this statement with examples.

Answer

The agro-industries in India have given a major boost to agriculture -
• Agro-based industries have given a boost to agriculture by raising its productivity.
• Agro-based industries depend on the agriculture for their raw materials such as cotton, sugarcane, jute etc.
• Agriculture depends on industries for products such as irrigation pumps, fertilizers, insecticides, pesticides, machines and tools, etc.
• Industrial development helps agriculture in increasing their production and make production processes very efficient.

4. Explain any three factors which were responsible for the concentration of cotton textile industry in Maharashtra and Gujarat in early years.

Answer
• Availability of raw cotton. 
• Ready markets are available. 
• Well-developed means of transportation.

5. Why is cotton textile industry the largest industry in India today? Give any three resons.

Answer

• Cotton textile industry contributes 14 percent of the total industrial production.
• It provides employment to 35 million persons directly – the second largest after agriculture. 
• It earns foreign exchange of about 24.6 percent (4 percent of GDP).

Long Answer Questions (LAQs):

1. Explain any five factors affecting the location of a industry.

Answer

The factors affecting the location of an industry:
• Availability of raw material.
• Availability of cheap labour.
• Availability of capital and bank facilities.
• Availability of power and other infrastructure.
• Proximity to markets.
• Availability of adequate and swift means of transport.

2. Mention the major drawbacks and problems of cotton textile industry in India.

Answer

Cotton textile industry in India suffers from some problems:
• India has world class production and quality in spinning, but weaving supplies low quality of fabric
because they are fragmented small units. This mismatch is major drawback.
• Many of our spinners export cotton yarn while apparel/garment manufactures have to import fabric.
• Although we the production of staple cotton has increased but we still need to import good quality staple cotton.
• Cotton textile industries face the problem of erratic Power supply which decreases the labour productivity.
• Machinery needs to be upgraded in the weaving and processing sectors in particular.
• Output of labour is low due to poor machines and power supply.

Value Based Question (VBQs):

1.“ Environmental degradation has been seen everywhere.” Explain any three values that can help to prevent environmental degradation.

Answer

Steps to minimise environmental degradation: 
• Optimum utilisation of equipment, adopting the latest techniques. 
• Upgrading existing equipment. 
• Minimising waste generation by maximising ash utilization.
• Providing green belts for nurturing ecological balance. 
• Reducing environmental pollution through ash pond management, water recycling system and liquid waste management.



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Extra Questions for Class 10th: Ch 7 Lifelines of National Economy Geography

October 19, 2018, 3:31 am
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Extra Questions for Class 10th: Ch 7 Lifelines of National Economy Social Studies (S.St) Important Questions Answer Included

Very Short Answer Questions (VSAQs): 

1. What is known as lifelines of the national economy?

Answer

Means of transport and communication.

2. What is a new arrival on the transportation map of India?

Answer 

Pipeline transport network is a new arrival on the transportation map of India to transport liquids as well as solids in slurry form.

3. Why was Jawaharlal Nehru port developed?

Answer 

To decongest the Mumbai port and serve as a hub port for the region.

4. Which is the deepest landlocked and well protected port?

Answer 

Visakhapatnam is the deepest landlocked and well protected port.

5. What are considered first-class mail by the Indian postal network?

Answer 

Cards and envelopes are considered first-class mail.

6. Why was the Haldia seaport Set-up?

Answer 

Haldia seaport was Set-up as a subsidiary port to relieve growing pressure on Kolkata port.

7. What is the major objective to develop Super Highways?

Answer 

The major objective of developing Super Highways is to reduce the time and distance between the mega-cities of India.

Short Answer Questions (SAQs):

1. Describe the rural roads in India?

Answer

• Rural roads link ruler areas and villages with towns. 
• These roads received special impetus under the Pradhan Mantri Grameen Sadak Yojna. 
• Special provisions are made so that every village in the country is linked to a major town in the country by an all season motorable road.

2. What are Golden Quadrilateral Super Highways? Mention any two objectives of this project. The North-South and East-West Corridors join which terminal cities.

Answer

• The Golden Qudrilateral Super Highways is a major road development project linking Delhi – Kolkata – Chennai – Mumbai and Delhi by six lane super highways. 
• The two major objectives of these Super Highways projects are to reduce the time and distance between the mega cities of India. 
• The North-South Corridors linking Srinagar (Jammu and Kashmir) and Kanyakumari (Tamil Nadu) and East-West Corridor connecting Silchar (Assam) and Porbander (Gujarat).

3. Elaborate any three advantages of railways in India.

Answer 

Advantages of railways in India are: 
• The road transport is cheaper than railway transport.
• It is suitable because it carries goods to other destination without re-handling any through the quickest route. It can provide door to door service. 
• Road transport is more flexible than railways as it has no fixed route or time.

Long Answer Questions (LAQs):

1. What is the importance of transport? Mention the various means of transport available in India.

Answer 

Importance of Transport: 
• Connects the people. 
• Sense of belonging in the people living at far places. 
• Helpful for business activities. 
• Helpful in the period of crisis.
 Means of transport: 
• Roadways 
• Railways 
• Pipelines 
• Waterways 
• Airways.

2. What is the significance of ‘Border Roads’? Explain.

Answer

• Border road organization was established in 1960. 
• This organization develops the roads of strategic importance in the North and the East border areas. 
• These roads have improved accessibility in areas of difficult terrain. 
• These roads have enabled the economy to develop in the border areas.



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Notes of Ch 3 From Gathering to Growing Food| Class 6th History

October 21, 2018, 11:21 am
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Notes of Chapter 3 From Gathering to Growing Food Class 6th History

Varieties of foods

• Most of our food such as fruit, vegetables, grain, milk and meat comes from plants that are grown and animals that are reared.

• Different plants grow in different conditions — rice, for example, requires more water than wheat and barley. 

• This explains why farmers grow some crops in some areas and not in other areas. Different animals too, prefer different environments — for instance, sheep and goat can survive more easily than cattle in dry, hilly environments.

The beginnings of farming and herding

• Domestication is the process in which the man grows the plants and protects the animals. Most of these animals tended by man become different from there wild counterparts.

• People often select the animals and plants to be domesticated by them. This process of domestication began some 12,000 years ago.

• Virtually all the plant and animal produces which we eat today are the result of Domestication.

‘Storing’ animals

• Animals multiply naturally. Besides, if they are looked after carefully, they provide milk, which is an important source of food, and meat, whenever required.

• In other words, animals that are reared can be used as a ‘store’ of food.

Finding out about the first farmers and herders

• The archaeologists have found evidence of early farmers and herders.

• These are found all over the subcontinent.

• Some of the most important ones are in the north-west, in present-day Kashmir, and in east and south India.

• To prove that these settlements belonged to farmers and herders, scientists study the evidences of plants and animals.

• Scientists have found burnt grain at these sites. These grains could have been burnt accidentally or purposefully. Also, bones of different animals are found.

• Based on these finds scientists confirm that a number of crops plants and animals existed in different parts of India sub-continent.

Towards a settled life

• Archaeologists have found traces of many things. They have use these things to know how the ancient people lived, what did the ancient people eat etc.,

• Traces of huts at some sites. For example, in Burzahom (in Kashmir) people built pit-houses, which were dug into the ground, with steps leading into them. These houses may have provided shelter in cold weather.

• Cooking hearths: Cooking places were found both inside and outside the huts, which suggests that, depending on the weather, people could cook food either indoors or outdoors.

• Neolithic tools: Included polished stone tools to give cutting edge and mortar pistils used for grinding grains. Along with these Neolithic tools, even the tolls of Paleolithic age were still used.

• Farmers and herders live in groups called tribes.

Living and dying in Mehrgarh

• Mehrgarh site is located in a fertile plain, near the Bolan Pass, which is one of the most important routes into Iran.

• Mehrgarh was probably one of the places where women and men learnt to grow barley and wheat, and rear sheep and goats for the first time in this area.

• It is one of the earliest villages that we know about.

Daojali Hading

• Daojali Hading is a site on the hills near the Brahmaputra Valley, close to routes leading into China and Myanmar. Here, stone tools, including mortars and pestles, have been found.

• These indicate that people were probably growing grain and preparing food from it. Other finds include jadeite, a stone that may have been brought from China.

• Also, common are finds of tools made of fossil wood (ancient wood that has hardened into stone), and pottery.

NCERT Solutions of Chapter 3 From Gathering to Growing Food

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Notes of Ch 4 Maps| Class 6th History

October 26, 2018, 7:55 am
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Notes of Chapter 4 Maps Class 6th History

A map is a representation or a drawing of the earth’s surface or a part of it drawn on a flat surface according to a scale. But it is impossible to flatten a round shape completely.

Different types of maps

Physical Maps

• Maps showing natural features of the earth such as mountains, plateaus, plains, rivers, oceans etc. are called physical or relief maps.

Political Maps

• Maps showing cities, towns and villages, and different countries and states of the world with their boundaries are called political maps.

Thematic Maps

• Some maps focus on specific information; such as road maps, rainfall maps, maps showing distribution of forests, industries etc. are known as thematic maps.

Components of Maps

Distance

• Maps are two-dimensional drawings. 

• It reduces the entire world or a part of the world on a small sheet of paper. 

• While making a map, cartographers pay attention to properly represent the distance between two places. This helps us in finding the actual distance between two places.

Small Scale Map

• When a large area is shown on a small map, such a map is called a small scale map. Example; map of a country or state.

Large Scale Map

• When a small area such as a village is shown on a map, such a map is called a large scale map.

•  A map of a neighbourhood is another example of large scale map. 

• A large scale map gives more details compared to a small scale map.

Direction

• A map also contains information about directions. 

• On most of the maps, you will usually see an upward arrow and the letter ‘N’. This shows the north direction. Once we know the north, we can easily find the other directions. North, South, East and West are the four major directions. These are called Cardinal Directions. 

• Some maps also show the intermediate directions, viz. north-east, south-east, south-west and north-west.

Compass

• Compass is very useful for finding directions at a place. This is a small circular box with a magnetic needle inside. The needle of the compass always points in the north-south direction. 

• Compass has been used by travellers and sailors since ages.

Symbols

• Cartographers also need to show various details like important structures, landmarks, etc. on a map. These things are shown by some standard symbols on the map.

• Some conventional symbols have been made on the basis of an international agreement. While using colours to show different themes and items on a map; certain conventions are followed. 

• Mountains are usually shown in brown colour, plains in green, water body in blue and plateau is shown in yellow.

Sketch

• A drawing based on memory is called a sketch. 

• A sketch is not made to scale. 

• A sketch map is useful when you need to show directions to your house to your friend.

Plan

• Drawing of a small area on a large scale is called a plan. 

• Architects usually make plans to show the layout of a house.


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Notes of Ch 3 Interior of the Earth| Class 11th Geography

October 7, 2018, 4:22 am
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Notes of Chapter 3 Interior of the Earth Class 11th Geography

Sources of Information about the Interior

• The earth’s radius is 6,370 km.

• As no one can reach the centre of the earth, most of our knowledge about the interior of the earth is largely based on estimates and inferences.

• There are two types of source of information available:
→ Direct Sources
→ Indirect Sources (Analysis of materials)

Direct Sources

• Surface rock or the rocks we get from mining areas.
→ Example: Gold mines in South Africa which are as deep as 3-4 km.

• Scientists have taken up a number of projects to penetrate deeper depths to explore the conditions in the crustal portions.
→ Example: “Deep Ocean Drilling Project” and “Integrated Ocean Drilling Project”. The deepest drill at Kola, in Arctic Ocean, has so far reached a depth of 12 km.

• Volcanic eruption.
→ As and when the molten material (magma) is thrown onto the surface of the earth, during volcanic eruption it becomes available for laboratory analysis.

Indirect Sources

• We know through the mining activity that temperature and pressure increase with the increasing distance from the surface towards the interior in deeper depths.
→ Moreover, it is also known that the density of the material also increases with depth.
→ Knowing the total thickness of the earth, scientists have estimated the values of temperature, pressure and the density of materials at different depths.

• Another source of information are the meteors that at times reach the earth.
→ However, it may be noted that the material that becomes available for analysis from meteors, is not from the interior of the earth but the material and the structure observed in the meteors are similar too that of the earth.
→ They are solid bodies developed out of materials same as, or similar to, our planet.

• The other indirect sources include gravitation, magnetic field, and seismic activity.
→ The gravitation force (g) is not the same at different latitudes on the surface. It is greater near the poles and less at the equator.
→ Magnetic surveys also provide information about the distribution of magnetic materials in the crustal portion, and thus, provide information about the distribution of materials in this part.
→ Seismic activity is one of the most important sources of information about the interior of the earth.

Earthquake

• An earthquake in simple words is shaking of the earth.

• It is caused due to release of energy, which generates waves that travel in all directions.

Why does the earth shake?

• Rocks along a fault tend to move in opposite directions. 

• As the overlying rock strata press them, the friction locks them together. However, their tendency to move apart at some point of time overcomes the friction. 
→ As a result, the blocks get deformed and eventually, they slide past one another abruptly. This causes a release of energy, and the energy waves travel in all directions. 

• The point where the energy is released is called the focus of an earthquake, alternatively, it is called the hypocentre.

• The point on the surface, nearest to the focus, is called epicentre. It is the first one to experience the waves.

Earthquake Waves

• All natural earthquakes take place in the lithosphere (depth up to 200 km from the surface of the earth.)

• An instrument called ‘seismograph’ records the waves reaching the surface.

• Earthquake waves are basically of two types
→ Body waves 
→ Surface waves.

• Body waves are generated due to the release of energy at the focus and move in all directions travelling through the body of the earth.

• The body waves interact with the surface rocks and generate new set of waves called surface waves. → These waves move along the surface.

• Body Waves are of two types - P-Waves and S-Waves

P-Waves

• These waves move faster and are the first to arrive at the surface and are also called ‘primary waves’.

• These are similar to sound waves and travel through gaseous, liquid and solid materials as sound.

• P-waves vibrate parallel to the direction of the wave.

S-Waves

• These waves arrive at the surface with some time lag and are called secondary waves.

• These waves can travel only through solid materials which has helped scientists to understand the structure of the interior of the earth.

• Reflection causes waves to rebound whereas refraction makes waves move in different directions.

• These waves are more destructive as they cause displacement of rocks, and hence, the collapse of structures occurs.

• The direction of vibrations of S-waves is perpendicular to the wave direction in the vertical plane. Hence, they create troughs and crests in the material through which they pass.

Shadow Zone

• Earthquake waves get recorded in seismo-graphs located at far off locations. However, there exist some specific areas where the waves are not reported. Such a zone is called the ‘shadow zone’.

• A zone between 105° and 145° from epicentre was identified as the shadow zone for both the types of waves.

• The entire zone beyond 105° does not receive S-waves. The shadow zone of S-wave is much larger than that of the P-waves.

• The shadow zone of P-waves appears as a band around the earth between 105° and 145° away from the epicentre.

Types of Earthquakes

• Tectonic Earthquakes: generated due to sliding of rocks along a fault plane.

• Volcanic Earthquakes:  A special class of tectonic earthquake. These are confined to areas of active volcanoes.

• Collapse earthquakes: In the areas of intense mining activity, sometimes the roofs of underground mines collapse causing minor tremors.

• Explosion earthquakes: Ground shaking may also occur due to the explosion of chemical or nuclear
devices.

• Reservoir induced earthquakes: The earthquakes that occur in the areas of large reservoirs.

Measuring Earthquakes

• The earthquake events are scaled either according to the magnitude or intensity of the shock.

Richter Scale

• The magnitude scale is known as the Richter scale. The magnitude is expressed in absolute numbers, 0-10.

Mercalli Scale

• The intensity scale is named after Mercalli, an Italian seismologist. The range of intensity scale is from 1-12.

Effects of Earthquakes

(i) Ground Shaking
(ii) Differential ground settlement
(iii) Land and mud slides
(iv) Soil liquefaction
(v) Ground lurching
(vi) Avalanches
(vii) Ground displacement
(viii) Floods from dam and levee failures
(ix) Fires
(x) Structural collapse
(xi) Falling objects
(xii) Tsunami

• The first six listed above have some bearings upon landforms, while others may be considered the effects causing immediate concern to the life and properties of people in the region.

• The effect of tsunami would occur only if the epicentre of the tremor is below oceanic waters and the magnitude is sufficiently high.

Structure of the Earth

The Crust

• It is the outermost solid part of the earth.

• It is brittle in nature.

• The thickness of the crust varies under the oceanic and continental areas. Oceanic crust is thinner as compared to the continental crust.

• The continental crust is thicker in the areas of major mountain systems.

• The type of rock found in the oceanic crust is basalt. The mean density of material in oceanic crust is 2.7 g/cm3.

The Mantle

• The portion of the interior beyond the crust is called the mantle.

• It extends from Moho’s discontinuity to a depth of 2,900 km.

• The upper portion of the mantle is called asthenosphere.
→It is the main source of magma that finds its way to the surface during volcanic eruptions.

• The crust and the uppermost part of the mantle are called lithosphere.
→ Its thickness ranges from 10-200 km.

• The lower mantle extends beyond the asthenosphere. It is in solid state

The Core

• The core-mantle boundary is located at the depth of 2,900 km.

• The outer core is in liquid state while the inner core is in solid state.

• The density of material at the mantle core boundary is around 5 g/cm33
.

• The core is made up of very heavy material mostly constituted by nickel and iron.

• It is sometimes referred to as the nife layer.

Volcanoes and Volcanic Landforms

• A volcano is a place where gases, ashes and/or molten rock material – lava – escape to the ground.

• A volcano is called an active volcano if the materials mentioned are being released or have been released out in the recent past.

• Volcanoes are classified on the basis of:
→ Nature of eruption
→ Form developed at the surface.

Types of Volcanoes

Shield Volcanoes

• Barring the basalt flows, the shield volcanoes are the largest of all the volcanoes on the earth.

• The Hawaiian volcanoes are the most famous examples.

• These volcanoes are mostly made up of basalt, a type of lava that is very fluid when erupted.

• They become explosive if somehow water gets into the vent; otherwise, they are characterised by low-explosivity.

Composite Volcanoes

• These volcanoes are characterised by eruptions of cooler and more viscous lavas than basalt.

• These volcanoes often result in explosive eruptions.

• The Deccan Traps from India, presently covering most of the Maharashtra plateau, are a much larger flood basalt province.

Mid-Ocean Ridge Volcanoes

• These volcanoes occur in the oceanic areas.

• There is a system of mid-ocean ridges more than 70,000 km long that stretches through all the ocean basins.

• The central portion of this ridge experiences frequent eruptions.

Volcanic Landforms

Intrusive Forms

• The lava that is released during volcanic eruptions on cooling develops into igneous rocks.

• The cooling may take place either on reaching the surface or also while the lava is still in the crustal portion.

• Depending on the location of the cooling of the lava, igneous rocks are classified as volcanic rocks (cooling at the surface) and plutonic rocks (cooling in the crust).

• The lava that cools within the crustal portions assumes different forms and these forms are called intrusive forms.

Caldera

• These are the most explosive of the earth’s volcanoes.

• They are usually so explosive that when they erupt they tend to collapse on themselves rather than building any tall structure.

• The collapsed depressions are called calderas.

Flood Basalt Provinces

• These volcanoes outpour highly fluid lava that flows for long distances.

• Some parts of the world are covered by thousands of sq. km of thick basalt lava flows.

Batholiths

• Batholiths are the cooled portion of magma chambers.

• They appear on the surface only after the denudational processes remove the overlying materials.

• They cover large areas, and at times, assume depth that may be several km. These are granitic bodies.

Lacoliths

• These are large dome-shaped intrusive bodies with a level base and connected by a pipe-like conduit from below.

• It resembles the surface volcanic domes of composite volcano, only these are located at deeper depths.

• It can be regarded as the localised source of lava that finds its way to the surface.

Lapolith, Phacolith and Sills

• As and when the lava moves upwards, a portion of the same may tend to move in a horizontal direction wherever it finds a weak plane.

• It may get rested in different forms. In case it develops into a saucer shape, concave to the sky body, it is called lapolith.

• A wavy mass of intrusive rocks, at times, is found at the base of synclines or at the top of anticline in folded igneous country. Such wavy materials have a definite conduit to source beneath in the form of magma chambers (subsequently developed as batholiths). These are called the phacoliths.

• The near horizontal bodies of  the intrusive igneous rocks are called sill or sheet, depending on the thickness of the material. The thinner ones are called sheets while the thick horizontal deposits are called sills.

Dykes

• When the lava makes its way through cracks and the fissures developed in the land, it solidifies almost perpendicular to the ground.

• It gets cooled in the same position to develop a wall-like structure. Such structures are called dykes.

• These are the most commonly found intrusive forms in the western Maharashtra area.

NCERT Solutions of Chapter 3 Interior of the Earth

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Extra Questions for Class 10th: Ch 13 Magnetic Effects of Electric Current Science

October 28, 2018, 9:08 am
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Extra Questions for Class 10th: Ch 13 Magnetic Effects of Electric Current (Science) Important Questions Answer Included

Very Short Answer Questions (VSAQs): 1 Mark

Q1. Name the measure used in domestic circuiting to prevent shock from leakage of current.
Earthing

Q2. An alternating current has frequency of 50Hz. How many times it has changed its direction in one second?
100 times, 50Hz frequency means AC generator completes 50 cycles in 1 second.

Q3. Name the rule which is used to find the direction of current carrying conductor in a wire.
Right hand thumb rule or Maxwell’s thumb rule

Q4. State the value of potential difference between the live wire and the neutral wire in our country.
220V

Q5. Mention the angle between a current carrying conductor and magnetic field for which the force experienced by this current carrying conductor placed in magnetic field is largest.
90°

Short Answer Questions-I (SAQs-I): 2 Marks

Q1. PQ is a current carrying conductor in the plane of the paper as shown in the fig. Mention the direction of magnetic fields produced by it at points A and B. Given : r1 < r2 where will the strength of the magnetic field be larger ? Justify your answer in each case.

Answer
Strength of magnetic field will be larger at A as the strength of magnetic field decreases when the distance is increased. Direction of magnetic field lines at A as well as B is anticlockwise because field lines are concentric circles and direction is determined by Right hand thumb rule.

Q2. How the strength of the magnetic field due to current carrying conductor does depends upon?

Answer

(i) distance  of the test point from the conductor
(ii) Magnitude of the Current flowing through the conductor

Q3. A current carrying wire entering a magnetic field experiences a force. In the diagram given below, a beam of electron is entering a magnetic field experience a force. From the below diagram, describe the direction of the magnetic field and direction of the current.

Answer

The direction of current is taken opposite to the direction  of the electron beam.  Now, current direction is from right to left.  The direction of magnetic field is given inside the paper. Now, if we apply Fleming’s left hand rule, we can obtain the direction of electron which is shown in the figure drawn. 

Q4. Write two reasons why appliances are connected in parallel in house hold circuiting?

Answer

(i) Each appliances are at same potential 
(ii) Each appliances can get individual switch

Q5.  Can two magnetic lines of force intersect each other ? Give reasons in support of your answer. 

Answer

No, two magnetic lines of force never intersect each other. If two magnetic lines of force intersect each other than at the point of intersection there will be two different directions of magnetic field which is not possible.

Short Answer Questions-I (SAQs-II): 3 Marks

Q1. What is an electromagnet ? How can we determine north and south pole of an electromagnet with the help of magnetised iron bar. 

Answer

An electromagnet is a device which generates magnetic field when electric current passes through it. 
It works on the principle of magnetic effect of current.
To suspend magnetised bar and identify its north and south poles. 
To find the polarity of electromagnet using the property-like poles repel. A bar magnet whose north and south pole is known, is brought near the poles of electromagnet. If north pole of bar magnet is deflected, that is south pole of electromagnet. 

Q2. State and explain Fleming's right hand rule for the direction of induced current. 


Answer

The direction of induced current in a straight conductor is given by Fleming's right hand rule. It states that , when we spread the thumb, forefinger and the middle finger of our right hand at right angle to one another  if the forefinger points in the direction of magnetic field, thumb gives the direction of force, then the direction in which the middle finger points, gives the direction of induced current.

Q3. Explain briefly two different ways to induce current in a coil. State the rule which determines the direction of induced current.

Answer

Two ways to induce current in a coil : (i) If a coil is moved in a magnetic field.
By bringing a bar magnet close to the coil or taking away from it. 
The direction is obtained by Flemings right hand rule.

Q4. Write one difference between direct current and alternating current. Which one of the two is mostly produced at power stations in our country ? Name one device which provides alternating current. State one important advantage of using alternating current.

Answer

The polarity of current remains same and current flows in same direction.  The direction of Alternating current changes after a regular time interval.
Most power stations produce AC in India/an AC generator. 
By using Alternating current, the power can be transmitted easily using transformers.

Long Answer Questions (LAQs): 5 Marks

Q1. State the principle of an electric generator. Draw a well labeled diagram of AC generator. Describe difference between AC and DC generator is design. 

Answer

Electric generator is based on the principle of electromagnetic induction. 
The brushes are attached permanently to the rings in AC generator. In DC generator, the split rings are present which changes carbon brushes at each half rotation. 

Q2. What are magnetic field lines ? List any two characteristics of field lines. Draw the pattern of magnetic field lines due to a current carrying circular loop

Answer

A magnetic field line is the path along which a free north pole tends to move. 
Characteristics : (a) Outside a magnet, the magnetic field lines are directed from N-pole of magnet towards S-pole. However, inside a magnet field lines are directed from S-pole to N-pole.
(b) The relative strength of magnetic field lines is given by degree of closeness of the field lines. More crowded field lines means a stronger field. 
(c) No two magnetic field lines can ever intersect each other. (any two).


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Notes of Ch 4 In the Earliest Cities| Class 6th History

November 3, 2018, 12:23 am
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Notes of Chapter 4 In the Earliest Cities Class 6th History

The story of Harappa

• Harappa is in modern day Pakistan. This site was accidentally discovered. The East India Company was doing the construction of railway lines in 1856.

• Initially, the construction workers thought the ruins to be of some ordinary old city. The bricks from the site were used for the construction. 

• It was about 80 years ago that archaeologists could realize that it was an ancient city.

What was special about these cities?

• Mohenjo–Daro, Kalibangan, Lothal and Dholavira are some other important sites of the Indus Valley Civilization. About 150 sites of this civilization have been discovered till date.

• Most of the sites this civilization are in modern day Pakistan. Some of the sites are in India, e.g. Kalibangan (Northern Rajasthan), Banavali (Haryana), Dholavira (Gujarat) and Lothal (Gujarat). 

• After excavations from different sites, it has become clear that this civilization was spread over major parts of western India and Pakistan and some parts of Afghanistan.

Special Features of these Cities

Town Planning

• These cities show immaculate town planning.

• The city of Harappa was divided into two parts, i.e. western and eastern parts.

• A huge tank has been found within the citadel. This has been named as the Great Bath by archaeologists. This was made from baked bricks.

• Rich people lived in the upper part of the city.

• Workers lived in the lower part of the city.

Use of Baked Bricks

• Houses and other structures were made of baked bricks.

• Bricks were of uniform size which means that the people of Harappa had developed good workmanship.

Roads and Drainage

• Roads were paved with bricks.

• The drainage system was properly planned. Drain from each house was connected to the drains in the streets.

Planned Houses

• The walls of the houses were strong and thick.

• Some of the houses were two storey high which shows the well-developed architecture in those days.

Granaries

• In the cities of the Indus Valley Civilization; a large granary has been found. Charred grains have been found in these granaries which shows that food grain production was surplus during this period.

• Historians also guess that taxes were collected in the form of grains.

• Grains collected as tax were stored in such large granaries.

Life of the People

Some of the possible occupations which may have existed in these cities are:

Craft

• Clay, copper and bronze was used for making pots. Tools, weapons and seals were made from copper and bronze. Seals were also made from clay. Some large pots have also been found. They were probably used for storing grains.

• Jewelleries were made of gold, beads, wood and clay. Precious stones; like cannelian, jasper, crystal, etc. were used to make beads.

• Clay and wood was used for making toys.

• Ornate carvings can be seen on toys, pots and jewellery.

Trade

• Trade was the main occupation of people of Harappa.

• Copper came from Rajasthan and from Oman. Some of the seals from Harappa have been found in Mesopotamia which shows that trade link existed between Harappa and Mesopotamia.

• A dockyard has been discovered in Lothal in Gujarat which shows that trade through sea route existed at that time.

Farming

• Remains of charred grains have been found which shows that wheat, barley, pulses, pea, rice, sesame, linseed and mustard was grown in the villages of the Harappa Civilization.

• A toy model of plough has been found from the ruins which show that plough was used for tilling the land.

• Bones of many domesticated animals have been found from the excavation site which shows that people of Harappa domesticated cattle, sheep, goat, buffalo and pig.

Some Other Aspects of Life

• Historians guess that the city of the Indus Valley Civilization was having some form of administration. There is a possibility of a committee of people to look after the administration.

• People used some form of entertainment. This is evident from toys and statues found from the site.

• Seals from the Harappa site show scripts on them. This shows that people of the city knew how to write.

• People worshipped gods and goddesses. Many statues have been found. This figure is similar to the Hindu god Lord Shiva.

Mystery over Decline of Harappa Civilization

• The Harappa Civilization suddenly declined around 3900 years ago. Broken roads and clogged drains indicate towards a decline in infrastructure.

• Historians have not yet identified the proper cause of the decline of the Indus Valley Civilization. Some guesses have been made which are as follows:

• There is a possibility that the rivers dried up. It forced people to move to some other places.

• There were too many brick kilns and furnaces. It may have damaged the environment. This would have led to deforestation. Lack of green cover may have forced people to move to some other places.

• Overgrazing by cattle and sheep may also have resulted in loss of forests. This would have led to desertification, i.e. formation of desert.

• There is also a possibility of large scale epidemic or natural calamity. It could have wiped off a major portion of the population.

NCERT Solutions of Chapter 4 In the Earliest Cities

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Extra Questions for Class 10th: Ch 14 Sources of Energy Science

November 3, 2018, 11:30 pm
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Extra Questions for Class 10th: Ch 14 Sources of Energy (Science) Important Questions Answer Included

Very Short Answer Questions (VSAQs): 1 Mark

Q1. Why thermal power points are set up near coal fields?
Answer
Transporting electricity is easier than transporting coal required for electricity generation in thermal power point.

Q2. Write one disadvantage of Hydroelectricity?
Answer
A large number of re habitation has to be done.

Q3. How the bi product of bio-gas plant is used?
Answer
It is used as fertilizer.

Q4. Write one drawback of nuclear power plant?
Answer
It generates radio activity which is dangerous for health.

Q5. How energy is converted from one form to another in wind energy generation?
Answer
Mechanical energy of rotatory blade  is converted into electrical energy.

Short Answer Questions-I (SAQs-I): 2 Marks

Q1. Why tidal energy is not exploited on a commercial scale?

Answer

Only few available sites suitable for building tidal dams and less efficiency of the plants based on energy of tides, make it non-feasible to exploit tidal energy commercially. 

Q2. It is advantageous to convert bio-mass into a bio-gas rather than burning bio-mass directly. How?

Answer

(i) The efficiency of bio-gas is much more than bio-mass.
(ii) The by product is used as fertilizers.

Q3. What is nuclear waste? What are the hazard of nuclear wastes?

Answer

The nuclear waste is spent or used fuels – the uranium. It decays into Sub atomic particles in form of radiations. These radiations are bad for health.

Q4. How wood is converted into charcoal? Why Charcoal is preferred over wood?

Answer

Wood is converted into charcoal by heating wood in absence of air. Charcoal is better than wood because it is more efficient source of energy.

Q5. Write two reasons why we should move for non-conventional Sources of energy?

Answer

(i) The conventional sources, basically fossil fuels are limited in stock.
(ii) The non-conventional sources have better environmental performances.

Short Answer Questions-I (SAQs-II): 3 Marks

Q1. Write three qualities of an ideal source of Energy.

Answer

(1) Efficiency: The source of energy should be efficient. The energy generation per unit amount of source of energy used should be high. 
(2) Eco-friendly: The source of energy should not harm environment by polluting air, water and soil.
(3) Easily storable and transferable: The source of energy should be easier to get stored and transferred to one place to another.

Q2. If energy cannot be created and destroyed, why we talk about energy crises?

Answer

It is true that energy cannot be created and destroyed, but we need to be concern about energy crises.  This is because :
(a) We have to convert energy in usable form and we not use it directly from environment.
(b) Any source of energy is not 100% efficient, so energy get lost in unusable form.
(c) Some source of energies are non- renewable and exhaustible which cannot be used again.

Q3 Name the process by which nuclear energy is generated? Also name one substance required for generation of nuclear energy. Write one advantage and one disadvantage of using Nuclear energy.

Answer

The process is nuclear fission. One Substances require for generation is uranium
Advantage : (i) For a given amount of fuel, the amount of energy released is extraordinarily large.
 Disadvantage : (i) Improper nuclear waste storage and disposal result in environmental contamination. 

Q4.  List two ways in which animal dung can be utilized as a fuel. Out of these two which one do you think is better? Justify your answer.

Answer

Two ways in which animal dung can be utilized are:
(i) as cowdung cakes.
(ii) By processing cowdung and converted into bio-gas.
Biogas is better than cow dung cakes because it has high heating capacity and non-polluting as it burns without smoke and leaves no residue like ash. By product in the process is a good manure for fields.

Q5. State three advantages of using charcoal as fuel.

Answer

(i) Charcoal has more efficiency of energy generation as compared to wood.
(ii) Charcoal releases less smoke on burning and hence does much less air pollution than wood.
(iii) It is easier to transport charcoal than wood.


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Extra Questions for Class 10th: Ch 15 Our Environment Science

November 4, 2018, 2:36 am
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Extra Questions for Class 10th: Ch 15 Our Environment (Science) Important Questions Answer Included

Very Short Answer Questions (VSAQs): 1 Mark

Q1. Why is excessive use of CFCs a cause of concern? 
Answer
When CFC'S reach upper layers of the atmosphere, they cause depletion of ozone layer, and allow harmful UV radiations to reach the surface of the earth to create health hazards. 

Q2. Name the gas which is produced due to incomplete combustion of fossil fuel.
Answer
Carbon monoxide. 

Q3. Select the item which is made up of biodegradable material — Plastic bag, leather bag, nylon rope, kettle.  
Answer
Leather bag. 

Q4 Name the gas which is produced due to incomplete combustion of fossil fuel. 
Answer
Carbon monoxide. 

Q5. List two natural ecosystems.
Answer
Forest, Lake

Short Answer Questions

Q1.  Write the appropriate name of the tropical levels X and Y, with an example?

Answer
(a) X is producer. Example- green plants
(b) Y is tertiary. Example-Hawk

Q2.  Accumulation of harmful chemicals in our bodies can be avoided. Explain how this can be achieved ? 

Answer

We should drink plenty of water, eat healthy food, perform exercise and do not take stress to avoid accumulation of harmful chemicals in our body. 
We should eat more vegetables especially cruciferous vegetables (such as broccoli, cauliflower, etc.) than meat so that biological magnification will be least.

Q3. List two reasons to show that the existence of decomposers is essential in an ecosystem.

Answer

(i) They help in the breakdown of organic matter or biomass of dead plants and animals into simple inorganic raw materials such as CO2, H2O and nutrients. 
(ii) They help in the natural replenishment of soil.

Q4. Energy flow in food chain is unidirectional. Justify the statement.

Answer

In a food chain the energy moves progressively through the various trophic levels and is no longer available to the organisms of the previous trophic level/ energy captured by the autotrophs does not revert back to the solar input.

Q5. We do not clean ponds or lakes, but an aquarium needs to be cleaned. Why?

Answer

Ponds and lakes are natural ecosystem and they have self-cleaning mechanism due to food chain and other environmental factors. But, an aquarium being an artificial eco-system do not have such mechanism.  Therefore, we need to clean aquarium. 

Q6. We often observe domestic waste decomposing in the bylanes of residential colonies. Suggest ways to make people realize that improper disposal of waste is harmful to the environment.

Answer

(i) Special sessions or festival on environmental theme should be called by colony local administrative bodies.
(ii) Street plays and short movies should be prepared highlighting the ill effects of improper disposal of wastes.


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Extra Questions for Class 10th: Ch 16 Sustainable Management of Natural Resources Science

November 4, 2018, 5:06 am
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Extra Questions for Class 10th: Ch 16 Sustainable Management of Natural Resources (Science) Important Questions Answer Included

Very Short Answer Questions (VSAQs): 1 Mark

Q1. State any two disadvantages of constructing dam.
Answer
(i) It affects bio-diversity.
(ii) It forces people to re habitat. 

Q2. Why fossil fuels should be used judiciously?
Answer
It is because these resources are limited, non-renewable and polluting.

Q3. What are 3 R’s used to save environment?
Answer
Reduce, Recycle and Reuse.

Q4. Define non-renewable sources of energy.
Answer
Non-renewable energy sources are which cannot be replaced easily when they get exhausted and are also called conventional sources of energy. Example : Fossil Fuels.

Q5. State one reason for the conservation of forest and wildlife.  
Answer
The conservation of forest and wildlife is necessary to restore the ecological balance.

Short Answer Questions-I (SAQs-I) : 2 Marks

Q1. For the conservation of forest who can be a stakeholder.

Answer

(i) The people who live in or around forest.
(ii) The forest department of the government.
(iii) The industrialists.
(iv) The wildlife and nature enthusiasts who want to conserve nature

Q2. "Reuse is better than recycling of materials". Give reason to justify this statement.


Answer

Reuse refers to the use of the same material again and again. In reuse of materials no energy is consumed and the resources are saved. In recycling certain used materials are converted into other useful materials. In recycling of materials, energy is consumed and the resources may be wasted.

Q3. Why are forests called as biodiversity hot spots?


Answer

Biodiversity hot-spot means a place where large number of species are found. Forests satisfy this criteria. In forest we can find variety of species of both flora and fauna. The range of different life forms i.e., bacteria, fungi, ferns, flowering plants, variety of animals likes, insects, birds, reptiles, aves, mammals etc. are all found in the forest.

Q4. Name the products of combustion of coal and petroleum. How do they effect our environment?


Answer

CO2 , H2O, oxides of sulphur and nitrogen are released from the combustion of coal and petroleum.
Effect on environment:
(i) CO2 — Green house effect, global warming.
(ii) Oxides of sulphur and nitrogen causes acid rain.

Q5. What are the advantages of water stored in ground?


Answer

(i) Water stored in ground does not evaporate.
(ii) It can be Recharges wells.

Short Answer Questions-II (SAQs-II) : 3 Marks

Q1. How does recycling of waste materials help in ecological balance? Write two causes with examples.


Answer

Recycling of waste materials can help in maintaining ecological balance in the following ways :

(i) By recycling the biodegradable wastes the nutrients present in them are returned to the nutrients pool of the environment like water and soil. These are reabsorbed by plants and utilised e.g. biogas from cow dung provide large amount of energy and the residue acts as a good manure.

(ii) Certain non-biodegradable waste like rubber and plastic pose serious disposal problems. Such substances can be recycled to manufacture usable articles. e.g. recycling of used polythene and aluminum foils.

Q2. Write three ways in which an individual can contribute in sustainable management of resources?


Answer

The three ways in which an individual can contribute in sustainable development are as under:

By sharing rides: People can share there rides with neighbours when there destination is nearby. This will reduce the consumption of petrol.

By using Led Bulbs: The Led Bulbs are having much less power consumption compared to electric bulbs. Thus, by using Led bulbs we can reduce the carbon emission

Afforestation: Planting trees will help to protect environment. Thus, the ecological balance will be maintained which has been compromised by the exploitation of fossil fuels.



Long Answer Questions (LAQs) : 5 Marks

Q1. What are fossil fuels? How are they formed? Why should we use them judiciously?


Answer

Fossil fuels are obtained from the remains of plants and animals which got burried under the earth some millions of year ago. They changed into fuel due to tremendous heat and pressure.
The fossil fuels should be used judiciously because they are non-renewable resources, and can not be made again. It releases harmful and polluting gases like CO2, which causes green house effect and oxides of nitrogen and sulphur which causes acid rain.


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Extra Questions for Class 9th: Ch 1 Matter in Our Surrounding Science

November 5, 2018, 12:53 am
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Extra Questions for Class 9th: Ch 1 Matter in Our Surrounding (Science) Important Questions Answer Included

Very Short Answer Questions (VSAQs): 1 Mark

Q1. Sponge is a solid yet we are able to compress it. Why?
Answer
There are minute holes in sponge in which air is trapped which is expelled out when compressed. Thus, sponge is compressible.

Q2. Define Condensation.
Answer
The change of solid state from liquid state on cooling is also known as Condensation.

Q3. At which the solid and liquid states of substance can exist together?
Answer
0°C

Q4.  Identify the name of the material which has no fixed shape but a fixed volume : Wood, a piece of iron, oxygen and water.
Answer
Water

Q5. What is the effect of pressure on boiling point?
Answer
Boiling point  increases with  increase in pressure.

Short Answer Questions-I (SAQs-I) : 2 Marks

Q1. Camphor disappears without leaving any residue. Explain?

Answer

Camphor disappears without leaving any residue because of sublimation, as it changes its state directly from solid to gas without changing to liquid.

Q2. Compare the rate of diffusion of liquids and solids with reason. 

Answer

(i) Rate of diffusion of liquids is higher than solid because the particles of liquid can move freely. 
(ii) Particles of liquid have greater spaces between them than solids. Thus, diffusion takes place easily. 

Q3. Write the chemical name of dry ice. Justify its name. How it is stored ? 

Answer

Chemical name of dry ice is solid CO2. 
Solid CO2 gets converted directly to gaseous state on decreasing the pressure to 1 atmosphere without coming into liquid state. Therefore, it is known as dry ice.
It is stored at high pressure.

Q4. Arrange the three states of matter in the increasing order of: 
(i) rate of diffusion
(ii) particle motion.

Answer

(i) Rate of diffusion: solid < liquid < gas.
(ii) Particle motion: solid < liquid < gas

Q5. Mention two properties of water to justify that water is liquid at room temperature. 

Answer

Water is liquid at room temperature because:
(i) It takes the shape of the container in which it is kept.
(ii) It can flow or shows fluidity. 

Short Answer Questions-II (SAQs-II) : 3 Marks

Q1. Explain why heat energy is needed to melt a solid. Define latent heat of fusion.

Answer

Heat energy is needed to melt a solid because there exist forces of attraction between the particles of solid. The heat energy helps in overcoming the forces of attraction between the particles and thus helps in melting a solid.
Latent heat of fusion is the amount of heat energy required to change 1 kg of solid into liquid at atmospheric pressure at its melting point.

Q2. An inflated air balloon deflates when pricked with a pin. Which property of the gaseous state is shown?

Answer

An inflated air balloon deflates when pricked with a pin due to the property of diffusion in gases. The molecules in a balloon are under higher pressure and the particles of gases are closely packed. When a pin is pricked on the surface of balloon, the diffusion from inside to outside takes place which is very fast process and hence the balloon deflates.

Q3. Why does the temperature remain constant during the change of state of matter? Explain it on the basis of change of solid state into liquid state.

Answer

The temperature remains constant as the heat gets used up in changing the state by overcoming the forces of attraction between the particles.
For example, a solid melts on heating. Its temperature does not rise until the entire solid is converted into liquid. This heat energy gets hidden into the contents and is known as the latent heat.


Long Answer Questions (LAQs) : 5 Marks


Q1. List any four factors on which evaporation depends. Explain in short any three factors.

Answer

The rate of evaporation depends on following factors:
(i) Surface area exposed to atmosphere
(ii) Temperature
(iii) Humidity
(iv) Wind speed

(i) Surface area exposed to atmosphere: Since evaporation is a surface phenomenon, therefore, it increases with an increase in surface area.

(ii) Humidity: The air around us cannot hold more than a definite amount of water vapour at a given temperature. If the amount of water in air is already high, the rate of evaporation decreases. So, evaporation decreases with increase in humidity.

(iii) Wind speed: With the increase in wind speed, the particles of water vapour move away with the wind, decreasing the amount of water vapour in the surroundings. This results in a faster rate of evaporation. So, evaporation increases with the increase in wind speed.

Q2. (a) Arrange the following matters in the increasing order of
(i) force of attraction
(ii) intermolecular space: 
Matters: iron nail, kerosene and oxygen gas.
(b) Define the following terms:
(i) Rigidity, (ii) Compressibility, (iii) Diffusion.

Answer

(a) (i) Force of attraction: Oxygen gas < Kerosene < Iron nail
(ii) Intermolecular space: Iron nail < Kerosene < Oxygen gas

(b) (i) Rigidity: It is the property of matter to maintain shape against external force.
(ii) Compressibility: It is the property of matter by virtue of which molecules of matter are brought closer to each other.
(iii) Diffusion: The inter mixing of the particles of matter is known as diffusion.


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Extra Questions for Class 9th: Ch 2 Is Matter Around us Pure Science

November 5, 2018, 11:48 pm
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Extra Questions for Class 9th: Ch 2 Is Matter Around us Pure (Science) Important Questions Answer Included

Very Short Answer Questions (VSAQs): 1 Mark

Q.1 How can you change a saturated solution to an unsaturated solution without adding any more solvent to it?
Answer
By heating the saturated solution, it becomes unsaturated.

Q.2 Sucrose (sugar) crystals obtained from sugarcane and beetroot are mixed together. Will it be a pure substance or a mixture? Give reasons for the same.
Answer
It is a pure substance because chemical composition of sugar crystals is same irrespective of its source.

Q.3 Based on which factor a solution is said to be diluted, concentrated or saturated?
Answer
A solution is said to be diluted, concentrated or saturated on the basis of the amount of solute dissolved in the solution.

Q.4 Identify solute and solvent in 'tincture of iodine'.
Answer
Iodine is the solute and alcohol is the solvent.

Q.5 What is mass per cent of a solution?
Answer
It is defined as the mass in grams of the solute present in one hundred grams of a solution.

Short Answer Questions-I (SAQs-I) : 2 Marks

Q. 1. 'Sea water can be classified as homogeneous as well as heterogeneous mixture.' Comment.

Answer

Sea water is a mixture of salts and water which cannot be separated except by evaporation. Therefore, sea water is considered homogeneous. Sea water also contains mud, decayed plant, etc., other than salts and water, so it is heterogeneous also.

Q.2. Why is it not possible to distinguish particles of a solute from the solvent in solution?

Answer

A true solution is homogeneous in nature. The solute and solvent particles are very small. They cannot be distinguished even under a microscope.

Q. 3. Explain why particles of a colloidal solution do not settle down when left undisturbed, while in the case of a suspension they do.

Answer

Particle size in a suspension is larger than those in a colloidal solution. Also molecular interaction in a suspension is not strong enough to keep the particles suspended and hence they settle down.

Q.4. Identify colloids and true solutions from the following:

Answer

Pond water, fog, aluminium paint, vinegar and glucose solution.
True solutions are vinegar and glucose solution. Colloids are fog, aluminium paint.

Q.5. Give two examples each for: (i) Aerosol, (ii) Emulsion. In what way are they different?

Answer

(i) Aerosol: Clouds, smoke
(ii) Emulsion: Milk, face cream. 0.6. Smoke and fog both are aerosols.

Both fog and smoke have gas as the dispersion medium. The only difference is that the dispersed phase in fog is liquid and in smoke it is a solid.

Short Answer Questions-II (SAQs-II) : 3 Marks

Q. 1. Describe any three properties of colloid.

Answer

(i) It is a heterogenous mixture.
(ii) Size of particles is too small to be seen by naked eye.
(iii) They scatter light passing through them making its path visible.
(iv) They do not settle down when left undisturbed.
(v) They cannot be separated by the process of filtration.

Q. 2. State the principle of separating two immiscible liquids by separating funnel. Describe an activity with diagram to separate a mixture of water and kerosene oil.

Answer

Immiscible layers separate out in layers depending on their densities in separating funnel.


Activity to separate kerosene oil from water using a separating funnel:

• Pour the mixture of kerosene oil and water in separating funnel as shown in figure.
• Let it stand undisturbed for sometime so that separate layers of oil and water are formed.
• Open the stopcock of the separating funnel and pour out the lower layer of water carefully.
• Close the stopcock of the separating funnel as the oil reaches the stopcock.

Q3. What would you observe when:
(a) a saturated solution of potassium chloride prepared at 60°C is allowed to cool at room temperature?
(b) an aqueous sugаr solution is heated to dryness?
(c) a mixture of iron filings and sulphur powder is heated strongly?

Answer

(a) Solid potassium chloride will separate out.
(b) Initially the water will evaporate and then sugar will get charred.
(c) Iron sulphide will be formed.

Long Answer Questions (LAQs) : 5 Marks

Q. 1. Differentiate between a true solution and a colloid.

Answer

True solution
Colloid
A true solution is a homogeneous mixture of two or more substances. A colloidal solution is a heterogeneous mixture of two substances.
The size of the particles is less than one nanometer.The range of particle size is between one nanometer to 1000 nanometer.
It is always transparent.It is translucent.
The particles cannot be seen even with microscope.The particles of a colloidal solution can be seen with microscope.
It does not show Tyndall effect.It shows Tyndall effect.

Q. 2. Distinguish between physical change and chemical change.

Answer

Physical change
Chemical change
In a physical change, only physical properties such as colour, physical state, density, volume etc. change, chemical properties remain unchanged.
In a chemical change, the chemical composition and chemical properties undergo a change.
No new substance is formed in a physical change.A new substance is formed in a chemical change.
Very little or no energy in the form of heat, light or sound is usually absorbed or given out in physical change.A chemical change is always accompanied by a absorption or evolution of energy.
A physical change is a temporary change.A chemical change is a permanent change.
The original form of substance can be regained by simple physical methods.Original substance cannot be obtained by simple physical methods.
A physical change is reversible.A chemical change is irreversible.


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Extra Questions for Class 9th: Ch 3 Atoms and Molecules Science

November 9, 2018, 4:53 pm
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Extra Questions for Class 9th: Ch 3 Atoms and Molecules (Science) Important Questions Answer Included

Very Short Answer Questions (VSAQs): 1 Mark

Q1.State the Law of Conservation of mass.
Answer
It states that mass can neither be created nor destroyed in a chemical reaction.

Q2. State the law of constant proportion.
Answer
Law of constant proportion states that in a chemical compound the elements are always present in a definite proportion by mass.

Q3. Explain what do you understand by valence electrons?
Answer
The electrons present in the outermost shell of an atom are called as valence electrons.

Q4. Name a non-metal that is tetra-atomic.
Answer
Phosphorus.

Q5. Give an example of:
(i) triatomic
(ii) polyatomic molecules of elements.
Answer
(i) Triatomic – Ozone O3
(ii) Polyatomic – Sulphur S8

Short Answer Questions-I (SAQs-I) : 2 Marks

Q 1. Write the chemical formula of:
(i) Sodium carbonate
(ii) Ammonium chloride

Answer


Q 2. (i) Explain what do you understand by Avogadro constant ?
(ii) Calculate the number of moles for 56 g of Ne. (Atomic mass Ne = 20 u)

Answer

(i) The exact number of atoms present in 12 gm of carbon-12 is called Avogadro constant.
(ii) No of moles = Given Mass/Molar Mass = m/M
= 56/20 = 2.8

Q4. (i) Write the chemical formula of a compound using zinc ion and phosphate ion.
(ii) Calculate the ratio by mass of atoms present in a molecule of carbon dioxide. (Given: C = 12, O = 16)

Answer

(i) Zn3(PO4)2(ii) The ratio by mass of constituting elements in carbon dioxide is:
CO2 = 12:(2 ×16) =12:32 = 3∶8

Short Answer Questions-II (SAQs-II) : 3 Marks

Q1. Show the formation of chemical formulae of following compounds using their ions:
(i) Ammonium sulphate
(ii) Magnesium nitrate
(iii) Aluminium sulphide

Answer



Q 2. Derive the molecular formulae for the following compounds:
(i) Copper bromide
(ii) Ammonium carbonate
(iii) Aluminium oxide.

Answer

(i) (𝐶𝑢+2) (𝐵𝑟-1)➝ 𝐶𝑢𝐵𝑟2
(ii)( 𝑁𝐻4) + (𝐶𝑂3)-2 ➝ [𝑁𝐻4]2𝐶𝑂3
(iii) (𝐴𝑙)+3(𝑂)-2 ➝ 𝐴𝑙2𝑂3

Q3. Write the chemical symbols of the following elements: Gold, Copper, Potassium, Silver, Platinum and Iron.

Answer

Gold = Au, Copper = Cu, Potassium = K, Silver = Ag, Platinum = Pt, Iron = Fe.

Q4. (a) Answer the following questions:
(i) Name the scientist who discovered protons.
(ii) What is the charge and mass of a proton?
(iii) Where is proton located in an atom?
(b) An atom of an element has atomic mass 28 u and its atomic number is 14. How many neutrons does it have? Also name the element.

Answer

(a) (i) E. Goldstein
(ii) Mass of proton = 1.67×10-27 kgs
Charge on a proton = 1.67 × 10-19 coloumb
Also charge is + 1 and mass is 1 unit.
(iii) Protons are located in the nucleus.
(b) Number of neutrons = 28 – 14 = 14. Element is silicon.

Q5. What is meant by the term chemical formula? Write the chemical formula of calcium oxide. Calculate its formula unit mass. (Atomic mass of Ca = 40 u, O = 16 u)

Answer

CaO - Calcium oxide
Formula unit mass of CaO = Atomic mass of Ca + Atomic mass of O = 40 + 16 = 56 u

Long Answer Questions (LAQs) : 5 Marks

Q 1. (i) Name the international organization who approves names of elements.
(ii) Give an example with explanation to show that the law of conservation of mass applies to physical changes also.

Answer

(i) International Union of Pure and Applied Chemistry (IUPAC).

(ii) When ice melts into water it is a physical change. Take a piece of ice in a small flask, cork it and weigh it and denote it as Wice gm.
Heat the flask gently and ice (solid) slowly melts into water (liquid). Then, weigh the flask again as Wwater gm.
It is found that there is no change in the weight i.e., Wice = Wwater
This shows law of conservation of mass holds true for physical changes.

Q 2. (a) A sample of vitamin C is known to contain 2.58 ×1019 oxygen atoms. How many moles of oxygen atoms are present in the sample?
(b) Write one word for the following:
(i) In a balanced chemical equation, the sum of the masses of reactants and products remains unchanged.
(ii) A group of atoms carrying a fixed charge on them.
(c) Write chemical formulae of the following compounds:
(i) Sodium phosphate
(ii) Ammonium carbonate

Answer



(b) (i) Law of conservation of mass
(ii) Ion
(c) (i) Na3PO4
(ii)( NH4)2CO3

Q3. (i) If 18 gm of pure water is electrolyzed, 2 gm of hydrogen and 16 gm of oxygen is obtained. Which law of chemical combination is illustrated by this statement?
(ii) State the law of constant proportion. Illustrate with the help of an example.
(iii)Which postulate of Dalton’s atomic theory is the result of law of conservation of mass?
(iv) Which point of Dalton’s atomic theory came from law of constant proportions ?

Answer

(i) Law of constant proportion.
(ii) A compound prepared by any method contains the same elements in the fixed ratio by mass. For example, H2O contains hydrogen and oxygen in the ratio 2: 16 i.e., 1: 8 by mass.
(iii) Atoms can neither be sub-divided, created nor destroyed.
(iv) Atoms of different elements combine in simple whole number ratios to form chemical compound.

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Notes of Ch 5 What Books and Burials Tell us| Class 6th History

November 9, 2018, 9:48 pm
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Notes of Chapter 5 What Books and Burials Tell us Class 6th History

One of the oldest books in the world

The oldest book known everywhere throughout the world should be that of the Vedas.

They were written around 3,000 years back and are the earliest literary source available.

The Vedas

• The word, Veda means Knowledge. There are four Vedas: Rigveda, Samaveda, Yajurveda and Atharvaveda.

• The Rigveda is the oldest Veda. It was created around 3,500 years back.

• The hymns have been compared by sages. These psalms were recounted and gone starting with one age then onto the next until the point when they were composed down.

• These hymns are in acclaim of various divine beings, for example, Indra (the lord of warrior), Agni (the divine force of flame), Varun (the lord of sky) and numerous others...

How do Historians study the Rigveda?

• While learning about the past, students of history examined written sources.

• They examined the Rigveda. A large portion of the psalms in Rigveda were as exchanges.

• Historians study these exchanges to arrive at conclusions.

Cattle, horses and chariots

• Most petitions in the Rigveda are for cows, kids and steeds.

• Horses were burdened to chariots and utilized as a part of fights.

• Battles planned to catch dairy cattle, arrive, field, water and individuals.

• A part of the riches was utilized for performing Yajnas or sacrifices in which offerings were put into flame, for divine beings including ghee, grains and uncommon creatures.

Words to Describe People

Political Life

• The Vedas even educate us concerning political existence of this sage.

• The head of state was called Raja.

• The Raja had no capital, castles, armed forces or ideal to gather charges.

Occupations

• Agriculture, cattle-rearing, chariot-production, ceramics, jewellery-production tanning and metal-work were the primary occupations.

Dasas/Dasyus

• While Aryans created Vedas, another gathering of individuals restricted to Vedas which were called Dasas or Dasyus or slaves.

Silent sentinels—the story of the megaliths

• Archaeologists expect that items found with a skeleton, likely had a place with the dead individual.

• In Brahmagiri, a skeleton was covered with 33gold dots, 2stone globules, and one conch shell though other skeleton just had a pot.

• This shows the distinction in status, among the general population who were covered. Some were rich while other were poor.

• Sometimes, stone monuments have more than one skeleton. It demonstrates that individuals having a place with a similar family were covered at same place however at various circumstances.

• Special burials occurred at Inamgaon.

• Animals were utilized as food. vii. Skeletal studies inform us regarding better method for recognizing dead bodies

NCERT Solutions of Chapter 5 What Books and Burials Tell us

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Extra Questions for Class 9th: Ch 4 Structure of the Atom Science

November 10, 2018, 5:20 am
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Extra Questions for Class 9th: Ch 4 Structure of the Atom (Science) Important Questions Answer Included

Very Short Answer Questions (VSAQs): 1 Mark

Q1. Define atomic number.
Answer
It is the number of protons in the nucleus of an atom.

Q2. What is an electron ? Who discovered it ?
Answer
Electron is a negatively charged particle present outside the nucleus of an atom. It was discovered by J. J. Thomson in 1897.

Q3. Name the particles which determine the mass of an atom.
Answer
Protons and Neutrons.

Q4. What will happen to an element ‘Z’ if its atoms gain three electrons?
Answer
It will change into trivalent anion i.e. Z3−

Q5. There are 15 protons and 16 neutrons in the nucleus of an element. Calculate its atomic number and its atomic mass.
Answer
Atomic number (Z) = Number of protons = 15
Atomic mass (A) = Number of protons + Number of neutrons = 15 + 16 = 31

Short Answer Questions-I (SAQs-I) : 2 Marks

Q1. Give one word for the following:
(i) Positively charged atom.
(ii) A group of atoms carrying a charge.

Answer

(i) Positively charged atom: Cation
(ii) Group of atoms carrying a charge: Polyatomic ion.

Q2. Which atom, Na+ or He, has completely filled K and L shells? Give reason to support your answer.
OR
Na+ has completely filled K and L shells. Explain.

Answer

Na: K=2, L=8, M=1
Na+: K=2, L=8
He: K=2
Na+ has completely filled K and L shells. Na atom gets converted into Na+ by losing one electron from its outermost shell. He atom has only K shell.

Q3. An atom of an element has three electrons in its 3rd orbit, which is the outermost shell. Write:
(i) The electronic configuration
(ii) Atomic number
(iii) Number of protons
(iv) Valency

Answer

(i) Electronic configuration : 2, 8, 3
(ii) Atomic number : 13
(iii) Number of protons – 13
(iv) Valency – 3

Q4. How many electrons, protons and neutrons will be there in an element 9𝑿19? What will be the valency of the element?

Answer

No. of protons =Atomic number = 9
No. of (protons + neutrons) = Mass number = 19
Number of electrons = 9
Number of protons = 9
Number of neutrons = Mass number–Atomic number = 19 – 9 = 10
Electronic configuration of X = 2, 7
Valency of X = 1 (since it requires one electron to complete its octet)

Q5. (a) J. Chadwick discovered a sub-atomic particle that has no charge and has mass nearly equal to that of a proton. Name the particle and give its location in the atom.
(b) If ‘K’ and ‘L’ shells of an atom are completely filled, then what would be: (i) the total number of electrons in the atom and (ii) its valency ?

Answer

(a) Particle is neutron. Neutron is present in the nucleus of an atom.
(b) (i) Total number of electrons = 10
(ii) Valency is zero.

Short Answer Questions-II (SAQs-II) : 3 Marks

Q1. The discovery of subatomic particles led to a revolution in the study of matter. Name the scientists who discovered these sub-atomic particles.

Answer

Electron: by J.J Thomson in 1897
Proton: by E. Goldstein in 1886
Neutron: by James Chadwick

Q2. Illustrate that Na atom has completely filled K and L shells.

Answer

Electronic configuration of Na is: 2, 8, 1
Since, K can have Maximum of 2 electrons using 2𝑛2 we can say that, it is filled completely. L can have maximum of 8 electrons, so, we can say it is filled completely.

Q3. Write the electronic configuration and valency of the following:
(i) Chlorine
(ii) Sodium and
(iii) Silicon

Answer

(i) E.C. of Cl = 2, 8, 7 Valency = – 1
(ii) E.C. of Na = 2, 8, 1 Valency = 1
(iii) E.C. of Si = 2, 8, 4 Valency = 4

Q4. There are two elements 26A13 and  26Al14. Find the number of sub-atomic particles in each of these elements. What is the relationship between the two?

Answer

 26A13
26 = 13 protons + 13 neutrons,
Atomic number = 26 – 13 = 13

26A14
26 = 14 protons + 14 neutrons
Atomic number = 26 – 14 = 12
They are isobars as they have same mass number but different atomic number.

Q5. (i) Why chemical properties of all the isotopes of an element are same?
(ii) Name the isotopes used in the treatment of goitre and cancer.
(iii) An element ‘X’ has 2 electrons in its M shell. What is its atomic number?

Answer

(i) This is because isotopes have same atomic number, so the number of valence electrons present in them are same and it is the valence electrons which take part in chemical reactions. So the isotopes of an element have same chemical properties.
(ii) Goitre – Isotope of iodine
Cancer – Isotope of cobalt

(iii) Atomic number of X = 12.

Long Answer Questions (LAQs) : 5 Marks

Q1. Hydrogen has three isotopes. State the composition of their nuclei and write their mass numbers. Also represent them in the form of symbols.

Answer

Isotopes of hydrogen are: Protium 1H1 (1 proton, 0 neutron), Mass no. :1,
Deuterium 1H2 (1 proton, 1 neutron), Mass no.: 2
Tritium 1H3 (1 proton, 2 neutrons), Mass no.: 3

Q 2. (i) Calculate the number of electrons, protons and neutrons in an atom of an element with atomic number 20 and mass number 40. Write electronic configuration and draw the structure of the atom.
(ii) An atom has complete K and L shells. Is this an atom of a metal, non-metal or noble gas? Justify.

Answer

(i) e = 20,
(ii) p = 20,
(iii) n = 40 – 20 = 20,
Electronic Configuration = 2, 8, 8, 2.

(ii) Atom has K = 2e; L = 8e
∴ Total electrons = 2 + 8 = 10e −
Complete shell with 8e −
∴ Noble gas

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Extra Questions for Class 9th: Ch 5 The Fundamental Unit of Life Science

November 13, 2018, 12:44 am
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Extra Questions for Class 9th: Ch 5 The Fundamental unit of Life (Science) Important Questions Answer Included

Very Short Answer Questions (VSAQs): 1 Mark

Q1. Plasma membrane is made up of which two components?
Answer
Plasma membrane is made up of lipids and proteins.

Q2. What is hypotonic solution?
Answer
A solution having solute concentration lower than that of the cell sap is called hypotonic solution.

Q3. What is hypertonic solution?
Answer
A solution having solute concentration higher than that of the cell sap is called hypertonic solution.

Q4. What is isotonic solution?
Answer
A solution having solute concentration same as that of the cell sap is called isotonic solution.

Q5. Cell wall is made up of which component?
Answer
Cell wall is made up of cellulose.

Q6. Give an example of unicellular organism.
Amoeba, Bacteria, Paramecium. (Any one)

Q7. Give an example of multicellular organism.
Answer
Fungi, plants, animals. (Any one)

Q8. What is active transport?
Answer
The movement of molecules across a membrane in cells against a concentration gradient with the help of ATP units is called active transport.

Short Answer Questions-I (SAQs-I) : 2 Marks

Q1. Cell size may range from a few micro metre to a metre. Support this statement with the help of examples.

Answer

Many cells are visible only under a microscope
Example: Mycoplasma is the smallest cell and longest cell in human body is nerve cell or neuron.

Q2. What is plasmolysis? What happens to a plasmolysed cell when it is placed in water?

Answer

Shrinkage of protoplast from the cell wall in presence of hypertonic solution due to exosmosis is know as plasmolysis. When a plasmolysed cell is placed in water, the concentration of water in the outside medium is more than the concentration in the cell. Hence, water moves inside the cell leading to its swelling.

Q3. What is plasma membrane ? What are its functions?

Plasma membrane also called as cell membrane, is the outer covering of a cell that separates its contents from the surrounding medium. It is made up of lipids and proteins, and provides a mechanical barrier to protect the inner contents of the cell. It encloses the nucleus and cytoplasm of the cell.

Q4. What do you mean by a nucleoid?

Answer

In prokaryotes and lower organisms like bacteria, the nuclear region of the cell may be poorly defined because of the absence of a nuclear membrane. Such an undefined and incipient nucleic region containing only naked nucleic acids without any membrane covering them is called a nucleoid.

Short Answer Questions-II (SAQs-II) : 3 Marks

Q1. (a) Write two points of difference between nuclear region of a bacterial cell and nuclear region of an animal cell.
(b) Which structure present in the nuclear region of a living cell bear genes?

Answer

Nuclear region of bacterial cell
Nuclear region of animal cell
Poorly defined and lacks any covering.Well defined and membrane bound.
Has single chromosome. Lacks true organelles.
Has more than one chromosome. Well defined membrane bound cell organelles present.

(b) Chromosomes is the structure present in the nuclear region of a living cell which bear genes.

Q2. (a) Label the parts marked 1, 2, 3 in a prokaryotic cell.

(b) Mention any three features of prokaryotic cells.

Answer

(a) 1 - Cell wall, plasma membrane,
2- Nucleoid,
3 - Cell wall

(b) (i) Lack nuclear membrane.
(ii) Lack cytoplasmic organelles.
(iii) Chlorophyll is associated with membranous vesicles.

Q3. (a) Why is the cell called the structural and functional unit of life?
(b) Why is the plasma membrane called a selectively permeable membrane ?
(c) Name the factor which decides the movement of water across the plasma membrane.

Answer

(a) Because shape and size of cells are related to specific functions they perform. Cells constitute various components of plants and animals.

(b) Because it permits exit and entry of some selected materials in and out of the cells.

(c) Amount of substance dissolved in water or solute concentration.

Q4. (i) Where are chromosomes present in the cell? What is their chemical composition?
(ii) How many pairs of chromosomes are present in human?

Answer

(i) Chromosomes are present in the nucleus of a cell. Their chemical composition is of DNA, RNA and proteins.
(ii) Hum have 23 pairs of chromosomes.

Long Answer Questions (LAQs) : 5 Marks

Q 1. (a) What are the consequences of the following conditions ?
(i) A cell having higher water concentration than the surrounding medium.
(ii) A cell having lower water concentration than the surrounding medium.
(iii) A cell having equal water concentration to its surrounding medium.
(b) Name the materials of which the cell membrane and cell wall are composed of.

Answer

(a) (i) When a cell possess higher water concentration than the surrounding medium then exosmosis occurs in the cell due to difference in concentration and cell shrinks.

(ii) When a cell has low water concentration than surrounding medium then endosmosis occurs that results in the swelling of the cell.

(iii) A cell having equal water concentration to its surrounding medium will not show any changes.

(b) Cell wall is composed of cellulose and cell membrane is composed of lipids and proteins.

Q2. (i) Explain the terms: (a) Endocytosis, (b) Plasmolysis.
(ii) What will happen if the organisation of a cell is damaged due to certain physical or chemical reasons?
(iii) How do substances like CO2 and water move in and out of the cell?

Answer

(i) (a) Endocytosis: The flexibility of the cell membrane enables the cell to engulf food and other materials from its external environment. Such process is known as endocytosis.

(b) Plasmolysis: When a living plant cell loses water through osmosis, there is shrinkage or contraction of the contents of the cell away from the cell wall. This phenomenon is known as plasmolysis.

(ii) When the organisation of a cell gets damaged, lysosomes will burst and their enzymes will eat up their own cell organelles. Therefore, lysosomes are also known as the suicidal bags of the cell.

(iii) Gases like CO2 and O2 move in and out of the cell by diffusion from their higher concentration to lower concentration. Water enters the cell by endosmosis through semi-permeable plasma membrane from its higher concentration to lower concentration. Similarly, water moves out of the cell by exosmosis when a cell is placed in a hypertonic solution.

NCERT Solutions of Chapter 5 The Fundamental Unit of Life

Notes of Chapter 5 The Fundamental of Life
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