CBSE Class 12

Detailed, Step-by-Step NCERT Solutions for 11 History Chapter 4 The Central Islamic Lands Questions and Answers were solved by Expert Teachers as per NCERT (CBSE) Book guidelines covering each topic in chapter to ensure complete preparation.

The Central Islamic Lands NCERT Solutions for Class 11 History Chapter 4

The Central Islamic Lands Questions and Answers Class 11 History Chapter 4

Question 1.
What were the features of the lives of the Bedouins in the early seventh century?
Answer:
Bedouin’s were nomadic tribes. They used to move from dry to green areas of the desert in search of food and fodder for their camels. Muhammad’s tribe was Quraysh. It owned/controlled main shrine in Mecca. Bedouins had stronger attachment to idols and shrines however, they have external sense that God is supreme like Jewish and Christian tribes. These were one of the tribes in Arab.

Question 2.
What is meant by the term ‘Abbasid revolution’?
Answer:
It was a revolution called dawa which brought down the Umayyads in 750. It not only overthrew Umayyads dynasty but the political structure and culture of Islam also. Muhammed’s uncle was Abbas and decendants of Abbas were Abbasids.

They spread a myth that a messiah (mahdi) from the family of the Prophet (ahl al-bayt) would liberate them from the oppressive Umayyad’s regime. Besides, they waged war against Umayyad dynasty, the Caliph Marwan was defeated in a battle at the river Zab. Thus, Abbasid revolution was a movement against Umayyad dynasty in which Abbasid dynasty took over the power of the state.

Question 3.
Give examples of the cosmopolitan character of the states set-up by Arabs, Iranians and Turks.
Answer:
Cosmopolitan character of the states set-up by Arabs, Iranians and Turks
(a) Arabs—

• There were several tribes but all of them accepted the Caliphate system of governance.
• As discrimination usually is found in cosmopolitan character, there were Arab and non-Arab individuals, Sunni and Siyas conflicting each-other.
• Society was ruled by varied canons which were in vogue e.g. claims differently for Calipha, a position of the deputy to God or the Shahenshah.
• Calendar depicts also the cosmopolitan nature of the state. It was Islamic calendar in which new year starts with Hijri.
• There were different languages spoken, different dresses the people wore.
• Islamic society exhibited multiple political and cultural patterns—one of the main features of cosmopolitan.

(b) Iranians —

• Agriculture was main occupation and taxes on land was the main sources of income to coffer.
• Nomaidic tribes gradually came to power in Iran i.e. Parthians, Sasanians.
• Urban centres were the main source of income to exchequer.
• Here also was the Islamic religion in vogue.

(c) Turks —

• Mixed with the Muslims and a different communities, all nomadic tribes.
• Different languages were spoken as the records of Shahenshah’s reveal.
• Fiscal arrangements and coinage were adopted as in other administrations.

On the premises above, we can state that the society during Arab, Iranian and Turks regime was of cosmopolitan nature.

Question 4.
What were the effects of the crusades on Europe and Asia?
Answer:
Effects on Europe—

• Hostility increased between Christendom and the Islamic world.
• Muslims addressed Christians as firangi.
• Holy land (Palestine) became the bone of contention.
• Salahaldin waged crusade against the Christian.
• Europe suffered severely. It waged crusades but could not save Palestine from the seizure of the Arabs.

Thus, the first effect on Europe was that of the harsher attitude of the Muslim state towards its Christian subjects. The second effect was that of increase in influence of Italian mercantile communities in trade between the east and the west even after the restoration of Muslim power.

Asia—
(i) Iranian merchants discovered silk route to China.
(ii) Trans Soxiano extended north to Russia and Scandinavia ‘ for the exchange of European goods and Slavic captives. s
(iii) For five centuries, Arab and Iranian traders monopolised the maritime trade between China, India and Europe.
(iv) Manufacture of paper (made from linen) started.

Question 5.
How were Islamic architectural forms different from those of the Roman empire?
Answer:

Question 6.
Describe a journey from Samarkand to Damascus, referring to the cities on the route.
Answer:
Presently, Samarkand falls under Russia and Damascus and it is a port city near Syria. The cities between this route were Antioch, Aleppo, Samarra, Daylam, Merv and Samarkand. It is confirmed by stating the routes adopted for trading that period.

Iranian merchants set-out from Baghdad along the silk route to China via the oasis cities of Bukhara and Samarkand (Transo Xiana). Trading items were mainly paper and silk. The paper manufacturing and exporting countries were in Central Asia and China.

Bukhara and Samarkand made commercial link from north to Russia and Scandinavia. Fur was the main item of trading from European countries including purchase of captives subsequently, made slaves. Islamic coins have been found by archaeologists along the Volga river and in the Baltic region.

Detailed, Step-by-Step NCERT Solutions for 11 Political Science Chapter 12  Freedom Questions and Answers were solved by Expert Teachers as per NCERT (CBSE) Book guidelines covering each topic in chapter to ensure complete preparation.

Freedom NCERT Solutions for Class 11 Political Science Chapter 12

Freedom Questions and Answers Class 11 Political Science Chapter 12

Question 1.
What is meant by freedom? Is there a relationship between freedom for the individual and freedom for the nation?
Answer:
The meaning of Freedom : The concept of Freedom is very wide and deep. There have been constant urge of human being to remain free and independent but history is full of examples which show that man and societies have been victim of exploitation by more powerful and tyranical groups.

However history also shows that there have been heroic struggles against such exploitations which proves the human urge for freedom. Is simple way we can say that freedom is the urge to live in one’s is own way without any external interference and control. Urge for freedom represents the desire of people to be in control of their own lives and destinies and to have right to express themselves through their own choices and activities.

Practical aspect of freedom can be understood in terms of free expression and actions with reasonable restrictions sanctioned by social, cultural and legal organisations and authorities.

There is close relationship between freedom for the individual and freedom for the nation. Nation is group of individual which behaves like an individual. There is no much difference of attributes of freedom of individual and freedom of nation, which behaves like a living creature and expects its own control.

Exploitation of a nation is like a exploitation of individual. Heroic struggle at national level against the national and communitari an exploitation shows the resemblance between individual freedom and freedom of nations.

Like many countries of the world who fought against their exploitation, India also fought a long battle against the colonials and empirical exploitation of India and ultimately got its freedom on 15th August’ 1947. Nelson Mandela and his colleagues waged long struggle against the British policy of racialism against the black and it was also a struggle to remove the obstacles to the freedom of all the people of South Africa. Mandela said in his book ‘Long Walk to Freedom’. Therefore we can say that urge of individual freedom represents the urge for national freedom or freedom of a Nation.

Question 2.
What is the difference between the negative and positive conception of liberty?
Answer:
There are two aspects of liberty, one is negative aspect and another is positive aspect of liberty.
1. Negative aspect of liberty
Negative aspect of liberty means ‘absence of restraints’ which means absolute liberty. It demands that to enjoy absolute liberty there should be no any kind of restraints, constraints or restrictions. A man should be allowed to develop in his own way in.all social, economic, cultural and political way. But this kind of liberty is not possible in a collective life in a civil society. There has to be some kind of adjustments and bindings in a collective life.

2. Positive aspect of liberty
Positive aspect of liberty seeks to expect a socio-economic and political environment in which further development of the people is conducive without any unreasonable restrictions. It means that positive aspect of liberty allows reasonable constraints and restrictions as long as they do not destroy the liberty itself.

It is based on the thinking that reasonable restrictions do not harms liberty rather it protects and promote liberty. Rousseau, Hegal, Marx and Gandhi were main supporters of the concept of positive aspect of liberty.

This aspect of liberty seeks to build the environment and kind of relationship between the individual and society that there are minimum restrictions. Positive liberty recognizes that one can be free only in society and not outside it. Therefore it requires such developments of the individuals in which their expression could be to the fullest extent.

Question 3.
What is meant by social constraints? Are constraints of any kind necessary for enjoying freedom?
Answer:
The word social constraints stands for social restrictions and social control on the expression and behaviour of man. These restrictions may come from domination and external control. These restrictions may be imposed through different methods like organisations and laws and by customs like caste system and inequilitarian structure of the society and the sense of high and low in the social system.

Social and legal constraints are necessary for the actual realisation of freedom or liberty provided the constraints and restrictions should be justified, reasonable. We need constraints for the sake of freedom of the people because without the reasonable constraints and restrictions, there will be no order in the society Which would invite the loss of freedom of the people.

Question 4.
What is the role of state in upholding freedom of its citizens?
Answer:
State Anarchists say that state is a hindrance in the freedom of man, therefore there should not be any institution like the State. Individualists say that ‘state is necessary evil’ hence propose a police state to protect human freedom from external aggressions and internal dangers.

Since in modem situation the concept of freedom and essential ingredients of freedom have changed therefore the role of state is also changed. Today it is accepted fact that we need constraints and reasonable restrictions to safeguard and protect the freedom. The legitimate and reasonable constraints are provided by the state because state has authority.

State is a supported system by the people. They have faith in them. Therefore they accept the directions and regulations of the states and mend their behaviour accordingly. State frame the useful policies and enact welfare laws for the people to make their life comfortable and meaningful which is the essence of freedom. Therefore state is playing positive role for upholding freedom.

Question 5.
What is meant by freedom of expression? What is your view would be a reasonable restriction on this freedom? Give examples.
Answer:
Freedom of expression is the fundamental requirement to make democracy meaningful and successful. Freedom of expression means that a person should be allowed to express himself or herself the way he likes i.e. through writings, acting, painting, speaking or through some artistic creation.

When we say that right of expression or to say the freedom of expression is the essence of democracy, we also have to accept that unbridled right of expression is also negation of democracy. For true realisation of freedom of expression, observance of responsibility and control through reasonable restrictions is must.

When we say that there should be restriction on the freedom of expression, but we will have to ensure that these restrictions should be reasonable which mean these restrictions should be just rational and humane so that freedom of expression is not destroyed while imposing restrictions.

We can substantiate this thesis by the example of India. Indian Constitution has provided Right of Expression to its citizen but there is also provision of imposing reasonable restrictions if the Right of Expression of the citizen will become prejudious to the law and order, peace and national security. So reasonable restriction can be imposed in given conditions with definite purpose whose authentity is open for judicial review.

Detailed, Step-by-Step NCERT Solutions for 11 Political Science Chapter 11 Political Theory: An Introduction Questions and Answers were solved by Expert Teachers as per NCERT (CBSE) Book guidelines covering each topic in chapter to ensure complete preparation.

Political Theory: An Introduction NCERT Solutions for Class 11 Political Science Chapter 11

Political Theory: An Introduction Questions and Answers Class 11 Political Science Chapter 11

Question 1.
Which of the following statements are true/false about Political Theory?
(a) It discusses ideas that form the basis of political institutions.
(b) It explains the relationship between different religions.
(c) It explains the meanings of concepts like equality and freedom.
(d) It predicts the performance of political parties.’
Answer:
a. True
b. False
c. True
d. False.

Question 2.
Politics is more than what politicians do. Do you agree with this statement? Give examples.
Answer:
Politics is deeply rooted in human nature Man is basically a selfish living being who is always found in expressed or unexpressed form of competition. Politics is the art of management of behaviour of others so as to impose or dictate one’s term. Politics is an art of dominance and it is also method of getting position of authority.

It is certainly not related with what the politican do or take the decisions about different matter, it is certainly something more. Politics is integral and important part of any society. Politics is also an attempt of better ways of governance. Mahatma Gandhi once observed that politics envelops us like the coi Is of a snake and there is no other way out but to wrestle with it.

Politics operate in groups, society and some form of political organisations for collective decision making. In politics negotiations take place to aquire collective decisions. It is therefore we can say that politics is wide concept with wide jurisdiction.

Question 3.
Vigilant citizens are a must for the successful working of a democracy. Comment.
Answer:
Democracy is called as the People’s government. It is said that in democratic form of government in which ultimate power rests with the people. It is called as most responsible and responsive government. This is based on discussion and debate on different issues at different levels. Democracy seeks to achieve important values like equality, justice, liberty for the people, dignity of the people and sense of brotherhood among different sections of the society.

For the success of democracy, certain pre-requisites are must, in which vigilant citizens are very essential. If the citizens are not aware about their rights and duties. If they do not know what the government is doing, what are the policies of the Government. If they do not put checks and restraint on the legislatures and executive they would become arrogant and will misuse their position and powers. In such situation the liberty and rights of the people will suffer and also democracy will be ultimate casualty.

It is, therefore, the people should make healthy public opinion on the basis of rational discussion and debate at different levels. For that people should have following qualities:-
1. There should be high level of literacy.
2. There should be economic and social equality.
3. People should have adequate employment.
4. People should be above caste, language and religious considerations to promote sense of brotherhood among them.

If these qualifications are missing in the society, democracy will be mobcracy, and there will not be effective control on the government. Vigilant citizens means responsible and aware citizens who could participate in the affairs of the government directly or indirectly.

Question 4.
In what ways is the study of political theory useful for us? Identify four ways in which political theory can be useful to us?
Answer:
Every subject has its theory. In fact no subject can move ahead without the theory. When a hypothesis is supported by facts, it becomes theory. Theory is generalisation which explain the whole situation. It is a factual statement. Whether it is science (physical science) or social science, every discipline has its theory. We have heard Darwin’s theory, Newton’s laws,

Archemedes principles all these theories have been source Of inspiration of new laws, principles and theories.’
Similarly every branch of social science, economics, sociology, political science, publ ic administration etc. have,their own theories which work as tools to study and analyse different situations and phenomenon. As far as the utility of political theory, we can explain in following points:-

• Theory i.e. Political theory gives the direction to the polity of a society.
• Political theory gives definite generalisations and tools and concepts which help in understanding the prevailing trends in the society.
• Political theory acts as an inspiration to move ahead.
• Political theory changes the society.
• Political theory makes movements and dynamism in the society.
• Political theory brings reforms in the society.
• Political theory brings revolution in the society.
• N. D. Studjy Material
• Political theory is relevant to all the target groups.
• Political theory helps us to have a basic knowledge of the political ideas and institutions that shape the society in which we live.
• Political theory removes confusions of the speiety.

Question 5.
Do you think that a good/convincing argument can compel others to listen to you?
Answer:
Theory denotes facts and rationalism theory is based on logical discussion and debate theory lies in reasoning capacities of man and the human behaviour based on reasoning. It is very much true that illogical statement not convince others for following. It is only logical and rational arguments which cast the positive impact for following:

Political theory examines questions which are causing Concern for the society and systematically thinks about the values that informs political life, values such as freedom, equality and justice. It explains the meaning and significance of these and related concepts is most convincing way.

As an advance level, it looks wheather existing institutions are adequate and how existing institutions and policy practices must be modified to be more democratic and relevant. Tlie objective of political theory is to train citizens to think rationally about political questions and assess the political events.

Question 6.
Do you think studying political theory is like studying mathematics? Give reasons for your answer.
Answer:
Studying political theory is certainly like studying mathematics in certain aspects only but not totally. Political theory is a factual statement based on certain facts which have empirical relevance. These facts are not numerical like the numerals of mathematics. Political theory is tested hypothesis.

It is as logical and rational is the problems and equations of mathematics. We can say that political theory is nearer to mathematics is qualitative facts and rational rather than quantitatively. In methodology also we find nearness in political theory, and mathematics.

Detailed, Step-by-Step NCERT Solutions for 11 Political Science Chapter 10 The Philosophy of the Constitution Questions and Answers were solved by Expert Teachers as per NCERT (CBSE) Book guidelines covering each topic in chapter to ensure complete preparation.

The Philosophy of the Constitution NCERT Solutions for Class 11 Political Science Chapter 10

The Philosophy of the Constitution Questions and Answers Class 11 Political Science Chapter 10

Question 1.
The following are’ certain laws.’Are they connected with any value? If yes, than what is underlying value? Give regions?
a. Both daughters and sons will have share in the family property.
b. There will be different slabs of sales tax on different consumer items
c. Religions instructions will not be given in any government school.
d. There shall be no beggar or forced labour.
Answer:
(a) Here in this sentence the value of equality is connected, because both sons and daughter have been treated equally in the share of family property.
(b) No value is connected.
(c ) Here also value of secularism is connected because the religious instruction is prohibited in government school as a result of secular nature of the state.
(d) No value is attached.

Question 2.
Which of the options given below cannot be used to complete the following statement?
a. Check the power of the government
b. Protect minorities from majority
c. Bring independence from colonial rule
d. Ensure that a long term vision is not lost by momentary passions.
e. Bring social change in peaceful manner.
Answer:
(c) Bring independence from colonial rule

Question 3.
The following are different positions about leading and understand¬ing constituent assembly debates.
1. Which of these statements argues that Constituent Assembly debates are relevant even today? Which statement says that they are not relevant?
2. With which of these positions do you agree and why?
a. Common people are too busy in earning livelihood and meeting different pressures of life. They can’t understand the legal language of these debates.
b. The conditions and challenges today are different from the time when the Constitution was made. To read the ideas of Constitution makers and use them for our new times is trying to bring past in the present.
c. Our ways of understanding the world and the present challenges have not changed totally. Constituent Assembly debates can provide us reasons why certain practises are important In a period when constitutional practises are being challenged, not knowing the reasons can destroy them.
Answer:
1. Statement ‘a’ and ‘b’ argues that the debates of Constituent Assembly are irrelevant today. While statement ‘c’. argues that debates of Constituent Assembly are relevant today.

2. J agree with position of statement ‘a’ that common people are too busy in earning livelihood, therefore they cannot understand legal language of the debates.

I also agree with the position of statement ‘c’ that debates of Constituent Assembly can provide us the reasons of importance of certain constitutional practices.

Question 4.
Explain the difference between the Indian Constitution and western ideas in the light of
a. Understanding of secularism
b. Art 370 and Art 371
c. Affirmative action
d. Universal adult franchise.
Answer:
‘A’ There are differences between the Indian Constitution in following areas although India is a secular state and western ideas also support secularism.

1. The western view of secularism is based on strict separation between the state and religion while in India state is allowed to interfere in religion for positive purpose. In India state is allowed to give aid to educational institution based on religion.

2. Here in India emphasis is on individual equality as well as inter community equality while in western ideas emphasis is on equality and individuals ‘B’ Art 370 and Art 371.

In India asymmetrical federalism prevails because Under Art 370 special status is given to Jammu & Kashmir and Art 371 provides special status to North eastern states to protect their local identity through constrictions on immigration. Indian federalism is asymmetrical in the sense also that centre is strong and has more powers than states. The western federations are symmetrical (Example, U.S.A.)

c. Affirmative action In Indian Constitution to improve the living conditions and status of traditionally backward sections of the society, provided reservation in matter of employment as a part of Affirmative action. Such Affirmative action is not given in western states.

d. Universal adult franchiseIn Indian Constitution and also is western constitution the principle of adult franchise has been accepted.

Question 5.
Which of these following principles of secularism are adopted in the constitution of India?
a. that state will have nothing to do with religion.
b. the state will have close relation with religion.
c. the state can discriminate among re{igion.
d. that state will recognise rights of religious groups.
e. that state will have limited powers to interfere in affairs of religions.
Answer:
‘D’ that the state will recognise right of religious groups.

Question 6.
Match the following

Answer:
Following are the correct matches
a – I, b – II, c – IV, d – V, e – III

Question 7.
This discussion was taking place in a class. Read the various arguments and state, which of these do you agree with and why.
Jayesh: I still think that our Constitution is only a borrowed document

Saba : Do you mean to say that there is nothing Indian in it? But is there such thing as Indians and western in the case of values and ideas? Take equality between men and women. What is western about it? And even if it is, should wo reject it only because it is western?

Jayesh: What I mean is that after fighting for independence from the British, did we not adopt their system of parliamentary government?

Neha: You forget that when we fought the British, we were not against the British as such, we were against the principle of colonialism. That has nothing to do with adopting a system of government that we wanted, wherever it came from. ‘
Answer:
On going through the above discussion between Jayesh and Neha, we find that both are correct to some extent. Jayesh is right that Indian Constitution is a borrowed bag because we have taken and adopted many systems and institution from different countries of the world, but we adapted them to our requirements.

Neha is also right that there is too much Indian is our Constitution. We have many precedents,-traditions and past history, which has shaped the formation of Constitution.

Government of India Act 1935 and Nehru Report 1928 forms the Indian sources of the Indian Constitution. We gave adopted the Constitution from different parts of the world as per our requirements and suitabilities.

Question 8.
Why it is said that the making of Indian Constitution was unrepresentative ? Does that make the Constitution unrepresentative? Give rea¬sons for your answer.
Answer:
It is said about the Constituent Assembly that it was unrepresentative, it is true to some extent because it was not directly elected by the people. It was based on the election of 1946. Secondly there was limited franchise and not adult franchise at that time. Thirdly most of the members were nominated to represent different sections of the society.

But we would say that it was a serious effort to make it the truely representative. It was the best effort in those circumstances. Direct election of the Constituent Assembly was not possible at that time. It was made for the people and its constitution was implemented and adopted in the name of ‘the people of India’. Therefore we can say that it was representative body.

Question 9.
One of the limitations of the Constitution of India is that it does not adequately attend to gender justice. What evidence can you give to substantiate this charge? If you were writing the Constitution today what provisions would you recommend for remedying this limitation.
Answer:
We feel that there are sufficient provisions to achieve the gender justice. For example Fundamental rights of Equality given in Art 14, 15 and 16 are sufficient attempt for gender Equality arid under justice.

There are sufficient provisions also in the chapter of ‘Directive Principles’ in the IVth part of the Constitution for the improved of living conditions and status of women. However there is nothing in the Constitution to achieve the gender justices in.practices because still we see the glancing situations of gender injustice. I would recommend the inclusion of practical provision to achieve the gender justice.

Question 10.
Do you agree with the statement that “It is not clear why in is a poor developing country, certain basic socio, economic rights were del¬egated to the section on Directive Principles rather than made an integral feature of our fundamental Rights?” Give reasons for your answer. What do you think are the possible reasons for putting socio, economic rights in the section of Directive Principles?
Answer:
It is true that basic socio-economic requirements have been included in the chapter of Directive Principles of the State Policy and notin the chapter of Fundamental Rights. But it is not so because the Constitution makers were less serious and concerned about these socio, economic need of the people.

Fact is that these needs were put in the chapter of Directive Principles because that is not justicible and did not put them in the chapter of Fundamental Right because it is justiciable.

Since there were inadequacy of the resources at the time of Constitution-making and constitution makers wanted to fulfill these socio-economic needs, therefore they put them in the chapter of Directive principles to be given by future governments and people could not claim them in the court of law.

Detailed, Step-by-Step NCERT Solutions for Class 11 Geography Chapter 2 Structure and Physiography were solved by Expert Teachers as per NCERT (CBSE) Book guidelines covering each topic in chapter to ensure complete preparation.

Structure and Physiography NCERT Solutions for Class 11 Geography Chapter 2

Structure and Physiography Questions and Answers Class 11 Geography Chapter 2

Question 1.
Choose the right answer from the four alternatives given below :
(i) In which part of Himalayas do we find the Karewa formation?
(a) North-eastern Himalayas
(b) Himachal-Uttaranchal Himalayas
(c) Eastern Himalayas
(d) Kashmir Himalayas
Answer:
(d) Kashmir Himalayas.

(ii) In which of the following states is Loktak lake situated?
(a) Kerala
(b) Uttaranchal
(c) Manipur
(d) Rajasthan
Answer:
(c) Manipur.

(iii) Which one of the water bodies separates the Andaman from the Nicobar?
(a) 11° Channel
(b) 10° Channel
(c) Gulf of Mannar
(d) Andaman Sea
Answer:
(b) 10° Channel.

(iv) On which of the following hill range is the ‘Dodabeta’ peak situated?
(a) Nilgiri hills
(b) Annamalai hills
(c) Cardomom hills
(d) Nallamala hills
Answer:
(a) Nilgiri hills.

Question 2.
Answer the following questions in about 30 words :
(i) If a person is to travel to Lakshadweep, from which coastal plain does he. prefer and why?
Answer:
The Lakshadweep islands are located at a distance of 280 km. to 480 km. off the Kerala coast. Malabar coast is in Karnataka and Kerala. The Malabar coast has got certain distinguishing features in the form of Kayals (Back waters). By this coastal plain one can travel to Lakshadweep island.

(ii) Where in India you will find a cold desert? Name some important ranges of this region.
Answer:
The north-eastern part of the Kashmir Himalayas is a cold desert, which lies between the Greater Himalayas and the Karakoram ranges. Between the Great Himalayas and the Pirpanjal range, lies the valley of Kashmir and Dal Lake.

(iii) Why is the western coastal plain devoid of any delta?
Answer:
Western coastal plain is a submerged coastal plain. The western coastal plains are narrow in the middle and broader towards north and south. This narrow belt provides a natural condition for the development of ports and harbours. The rivers flowing through this coastal plain do not form any delta.

Question 3.
Answer in less than 125 words :
(i) Make a comparison of the island groups of the Arabian Sea and the Bay of Bengal.
Answer:
There are two major islands groups in India :
(i) in the Bay of Bengal and
(ii) in the Arabian sea

(ii) What are the important geomorphological features found / in the river valley plains?
Answer:
The third geological division of India is the plains formed by the river. Indus, the Ganga and the Brahmaputra known as river valley plains. It was formed during the third phase of Himalayan mountain formation. It has been gradually filled by the sediments brought by the Himalayan and peninsular rivers.

It is evident from the above discussion that there are significant variations among different region of India interim of their geological structure. Variation in physiography and relief is important among these. The geology and geomorphology of Indian river valley plain greatly influenced the physiography of India. The plains are formed by the alluvial deposits brought by the rivers.

The Brahmaputra river flows from the north-east to south-west direction and enters into Bangladesh. These river valley plains have a fertile alluvial soil cover which supports a variety of crops like wheat, rice, sugarcane and jute, and hence, supports a large population.

(iii) If you move from Badrinath to Sunderban delta along the course of river Ganga, what major geomorphological features will you come across?
Answer:
Ganga rises in Gangotri glacier near Gomukh (3,900 m) in Uttarkashi. Here it is known as Bhagirathi. It cuts through the Central and Lesser Himalayas in narrow gorges. At Devprayag, the Bhagirathi meets the Alaknanda; from here it is known as Ganga. The Ganga enters the plains at Haridwar.

From here it flows first to the south, then to the southeast and east before splitting into its two distributaries namely the Bhagirathi and the Hugli. The river finally discharges itself into the Bay of Bengal forming a large Sunderban delta formed by the mouth ‘ of river Ganga. Otherwise, this is a featureless plain.

Detailed, Step-by-Step NCERT Solutions for Class 11 Geography Chapter 8 Composition and Structure of Atmosphere Questions and Answers were solved by Expert Teachers as per NCERT (CBSE) Book guidelines covering each topic in chapter to ensure complete preparation.

Composition and Structure of Atmosphere NCERT Solutions for Class 11 Geography Chapter 8

Composition and Structure of Atmosphere Questions and Answers Class 11 Geography Chapter 8

Question 1.
Multiple choice questions :
(i) Which one of the following gases constitutes the major portion of the atmosphere?
(a) Oxygen
(b) Nitrogen
(c) Argon
(d) Carbon dioxide
Answer:
(b) Nitrogen.

(ii) Atmospheric layer important for human beings is …………
(a) Stratosphere
(b) Mesosphere
(c) Troposphere
(d) Ionosphere
Answer:
(c) Troposphere.

(iii) Sea salt, pollen, ash, smoke, soot, fine soil – these are associated with
(a) Gases
(b) Dust particles
(c) Water vapour
(d) Meteors
Answer:
(b) Dust particles.

(iv) Oxygen gas is in negligible quantity at the height of atmosphere
(a) 90 km
(b) 120 km
(c) 100 km
(d) 150 km
Answer:
(b) 120 km.

(v) Which one of the following gases Ls transparent to incoming solar radiation and opaque to outgoing terrestrial radiation?
(a) Oxygen
(b) Nitrogen
(c) Helium
(d) Carbon dioxide
Answer:
(d) Carbon dioxide.

Question 2.
Answer the following questions in about 30 words each :

(i) What do you understand by atmosphere?
Answer:
Atmosphere is a mixture of different gases, which envelopes the earth all round. It contains life-giving gases like oxygen for man and animals and carbon-dioxide for plants.

(ii) What are the elements of weather and climate?
Answer:
Wind, temperature, pressure, clouds, humidity and precipitation are the chief elements of weather and climate.

(iii) Describe the composition of atmosphere.
Answer:
Atmosphere is a mixture of various gases. Pure dry air consists of nitrogen, oxygen, argon and carbon dioxide.

Composition of the atmosphere

Dust particles, smoke, salt, water vapour are also present in the lower layer of the atmosphere.

(iv) Why is troposphere the most important layer of all the layers of the atmosphere?
Answer:
Because this layer contains dust particles and water vapour. Its thickness is greatest at the equator (about 18 km) because heat is transported to great heights by strong place in this layer. This is the most important layer for all biological activity. This helps to maintain the temperature of the earth.

Question 3.
Answer the following questions in about 150 words each :
(i) Describe the composition of the atmosphere.
Answer:
The composition of the atmosphere is shown in Table 8.2. It is clear from the table 8.2 that nitrogen and oxygen make up 99% of the clean dry air of the atmosphere. In addition, it contains small amount of C02, water vapour, ozone, inert gases like xenon, krypton, neon and argon and amounts of solid and liquid particles, collectively called aerosols.

Even though nitrogen and oxygen comprise 99% of the total volume of the atmosphere, they are climatically of little consequence. Nitrogen does not easily enter into chemical union with other substances, but gets fixed in the soil. It serves mainly as diluent or dissolves. It regulates combustion. Oxygen, on the other hand, combines with all the elements and is most combustible.

Carbon dioxide although constitutes a small percentage, it is an important gas in the atmospheric process. It can absorb heat and thus allows the lower atmosphere to be warmed up by heat radiation coming from the sun and from earth’s surface. Green plants in the process of photosynthesis utilise carbon dioxide from the atmosphere.

(ii) Draw a suitable diagram for the structure of the atmosphere and label and describe it.
Answer:
The atmosphere is divided into two broad layers – homosphere and heterosphere and ten sub-layers (Table 8.1). Homosphere consists of 6 sub-layers and there are four in heterosphere.

The homosphere extends up to the height of 90 km. It is characterised by uniformity in chemical composition. It consists of three thermal layers – troposphere, stratosphere and mesosphere.

The lowest layer of homosphere is called troposphere. It is 10 km. thick at the poles and 16 km. at the equator.

Troposphere is overlain by tropopause. It separates it from the overlying layer of stratosphere. In the troposphere temperature ceases to decrease with increasing height.

The layer above the tropopause, stratosphere is the zone of clean and clear air. Jet aircrafts fly through the lower stratosphere because it provides easiest flying conditions. Stratosphere contains the ozone layer,

which absorbs the sun’s harmful ultraviolet rays. The upper boundary of the stratosphere is called stratopause. It lies at a varying altitude of about 50 km. Above the stratopause lies mesosphere. The mesosphere extend from 50-90 km. in altitude.

The second major layer, heterosphere, has heterogeneous chemical composition with layered structure of nitrogen, oxygen, helium and hydrogen. Its first layer, thermosphere, extends above mesopause, and continues to edge of space about 60,000 km. less above the earth’s surface.

Temperature rises spectacularly in this layer and reaches 900°C at 350 km. Thermosphere absorbs ultraviolet radiation. This region is the source of ionosphere. Disturbances in this region appear as glowing lights of varying colours – aurora. This layer reflects radio waves. Ionized particles intermittently create a sheet like display of light called Aurora Borealis in the northern hemisphere and Aurora Australis in the southern hemisphere.

Exosphere and magnetosphere are other layers of heterosphere. Exosphere is extremely rarefied and is composed mainly of hydrogen and helium.

Magnetosphere is the outermost layer of the atmosphere. It has distinct layers of nitrogen, oxygen, helium and hydrogen.