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On this page, you will find Friction Class 8 Notes Science Chapter 12 Pdf free download. CBSE NCERT Class 8 Science Notes Chapter 12 Friction will seemingly help them to revise the important concepts in less time.

CBSE Class 8 Science Notes Chapter 12 Friction

Friction Class 8 Notes Understanding the Lesson

1. Friction opposes the relative motion between two surfaces in contact. It acts on both the surfaces.

2. Friction always acts in a direction opposite to the direction of motion.

3. The force of friction always opposes the applied force. So it is defined as a force that opposes motion.

4. Friction depends upon the nature of surfaces in contact. It also depends upon the weight of the body.

5. Friction is greater in rough surface and smaller in smooth surface.

6. Friction is caused by the interlocking of irregularities between the two surfaces, Friction is independent of the area of contact.

7. Friction is both a friend and a foe. It is a necessary

8. Friction can never be reduced to zero.

9. Friction is also caused due to the force of adhesion.

10. The substances that reduce friction are known as I lubricants. They form a thin layer on the moving I surfaces. So, they do not rub directly against each other.

11. Friction can be reduced by using grease, oil, powder, ball bearings and a cushion of dry air between the 1 moving surfaces.

12. The force required to overcome friction at the instant an object starts moving from rest is a measure of static friction. It comes into play when try to move an object at rest.

13. When one body or object rolls over the surface of another body or object, the resistance to its motion is known as rolling friction.

14. When one object slides over another object, the friction that comes into action is called sliding friction.

15. The force of friction exerted by fluids is also known as drag. The common name of gases and liquids is fluid.

16. Ball bearings are used to reduce friction.

17. Fluid friction of an object depends upon its speed with respect to the fluid, the shape of the object and the nature of the fluid.

18. A special shape is given to overcome drag of an object. For example, shape of an aeroplane and ship are streamlined. Birds and fish have naturally got such shape.

19. Sometimes we deliberately increase friction by using brake pads in the brake system of bicycles and auto¬mobiles and by grooving soles of shoes or tyres of vehicles, etc.

Class 8 Science Chapter 12 Notes Important Terms

Ball bearing: A bearing in which the parts are separated by a ring of small freely rotating metal balls.Ball bearings are used to reduce friction.

Drag: The frictional force exerted by fluids is called drag.

Fluid friction: Friction that occurs in liquids or gases is called fluid friction.

Friction: The resistance that one surface or object encounters when moving over another is known as friction. It opposes the relative motion between two surfaces in contact.

Interlocking: Irregularities in two surface may clasp with each other, resulting in their interlocking.

Lubricants: The substances that reduce friction are called lubricants.

Rolling friction: When one object rolls over another object, the resistance to its motion is called rolling friction.

Sliding friction: When one surface slides over another surface, sliding friction gets into action.

Static friction: To counter balance the applied force on the object, static friction comes into action.

On this page, you will find Force and Pressure Class 8 Notes Science Chapter 11 Pdf free download. CBSE NCERT Class 8 Science Notes Chapter 11 Force and Pressure will seemingly help them to revise the important concepts in less time.

CBSE Class 8 Science Notes Chapter 11 Force and Pressure

Force and Pressure Class 8 Notes Understanding the Lesson

1. A push or pull on an object is called force.

2. Forces applied on an object in the same direction add to one another.

3. If two forces act in the opposite directions on an object, the net force acting on it is the difference between the two forces.

4. The strength of a force is usually expressed by its magnitude.

5. Force on an object may change its state of motion, speed, direction and shape.

6. The force resulting due to the action of muscles is known as the muscular force.

7. Muscular force can only be applied when it is in contact with an object, it is also called as contact force.

8. The force responsible for changing the state of motion of an object is known as the force of friction.

9. The force exerted on an object without touching it is known as non-contact force.

10. The force exerted by a charged body on another charged or uncharged body is known as electrostatic force.

11. The attractive force of the earth which acts upon all the objects is known as the force of gravity or just gravity. This force is known as gravitational force.

12. The force acting on a unit area of a surface is called pressure.

13. The envelop of air around us is known as atmosphere.

14. The pressure exerted by the atmosphere is known as atmospheric pressure.

Class 8 Science Chapter 11 Notes Important Terms

Atmospheric pressure: The pressure exerted by air around us is termed as atmospheric pressure.

Contact force: The type of force which acts only when the object are in physical contact with each other is called contact force.

Electrostatic force: The force exerted by an electrified body is called electrostatic force.

Force: A push or pull which tends to change the state of rest, motion direction, size and shape is called as force.

Friction: The force acting between two surfaces in contact which opposes the motion of one body over the another body is called the force of friction.

Gravitational force: The force of attraction between any two objects which have mass is called gravitational force.

Gravity: The force of gravitation which acts on the bodies close to the surface of the earth is called the force of gravity of the earth.

Magnetic force: The type of force which is exerted by a magnet is called magnetic force.

Muscular force: The type of force which is exerted by the muscles of a human or animal body is called muscular force.

Non-contact force: The type of force which is exerted by a body on another body without any direct contact with it is called non-contact force.

Pressure: Force acting per unit area is called pressure.

Pull: The type of force which move the object towards source of the force.

Push: The type of force which move the object forward or away from the source of force.

On this page, you will find Reaching the Age of Adolescence Class 8 Notes Science Chapter 10 Pdf free download. CBSE NCERT Class 8 Science Notes Chapter 10 Reaching the Age of Adolescence will seemingly help them to revise the important concepts in less time.

CBSE Class 8 Science Notes Chapter 10 Reaching the Age of Adolescence

Reaching the Age of Adolescence Class 8 Notes Understanding the Lesson

1. The period of life, when the body undergoes changes, leading to reproductive maturity, is called adolescence. It begins around the age of eleven and lasts upto eighteen or nineteen years of age. Hence adolescence occurs between childhood and adulthood.

2. The human body undergoes several changes during adolescence such as change in body shape, voice change, development of sex organs, etc.

3. The phase wherein the bodily changes occurs in terms of sexual growth, is known as puberty. Therefore puberty is defined as the onset of reproductive maturity, starting at the age of 11 years and lasts till the age of 18 years. It starts earlier in females than in males.

4. During adolescence, in girls, the region below the waist becomes wider whereas in boys, shoulders broaden and the muscles of the body grow more prominently than girls.

5. At puberty, the voice box or the larynx begins to grow. Boys develop larger voice boxes and produce hoarse voice whereas girls have a high pitched or shrilled voice. The growing voice box in boys can be seen as a protruding part of the throat called Adam’s apple.

6. There is a sudden change in height of human beings during puberty. The height increases faster in girls than boys and both reach their maximum height at the age of 18.

7. During puberty the secretion of sweat glands and sebaceous glands (oil glands) increases which results in development of acne and pimples on the face of boys and girls.

8. In the period of adolescence, a person reaches the maturity level of mental, intellectual and emotional thinking.

9. During puberty, breasts begins to develop in girls; facial hair, i.e., moustache and beard in boys. These features which distinguish the male from female are called secondary sexual characters.

10. The changes which occur at adolescence are controlled by hormones which are chemical substances. They are secreted from endocrine glands, or endocrine system.

11. The male hormone or testosterone is released by the testes and the female hormone or estrogen is produced by ovaries are responsible for secondary sexual characters in both of them. The production of these hormones are under the control of pituitary gland.

12. Hormones from pituitary stimulate testes and ovaries to release male (testosterone) and female (estrogen) hormone into the blood stream which reach a particular body part called target site. The target site responds to the hormones. The testes and ovaries secrete sex hormones which are responsible in the male and female secondary characters.

13. Reproductive phase of life in humans start when their testes and ovaries begin to produce gametes. In male, the reproductive phase begins at puberty at the ages 14 – 15 and lasts, as long as he is healthy whereas in female it begins at the ages 10-12 and lasts until the age of 45-50 years.

14. The uterine wall in females prepare itself to receive the developing fertilised egg. In case there is no fertilisation, the thickened lining of the uterine wall breaks down along with blood. This is called menstruation.

15. The first menstrual flow begins at puberty is termed as menarche.

16. Stoppage of menstruation at the age of 45-50 is termed as menopause.

17. Sex of unborn child depends on whether the egg is fertilised with sperm having X or Y chromosome.

18. The thyroid gland produces the thyroxine hormone which prevents from ‘goitre’ disease. Similarly, the pancreas produces the insulin hormone which checks the disease ‘diabetes’. The adrenals produce hormone 1 adrenaline which helps the body to adjust to stress when one is very angry, embarrassed or worried.

19. The adrenals and thyroid secrete their hormone when they receive orders from the pituitary through its I hormones. The pituitary also secretes growth hormone which is necessary for the normal growth of a person.

20. Hormones play a vital role in completing life cycle in insects and frogs. For example, metamorphosis (changing of larva into adult) in insects is controlled by insect hormones. In a frog, it is controlled by thyroxine, the hormone produced by thyroid. The production of thyroxine needs the presence of iodine in water.

21. Nutritional needs of the adolescents: At the stage of adolescence, the human body grows at an extremely fast rate and requires adequate intake of a balanced diet which should contain proportionate I amount of proteins, carbohydrates, fats, vitamins and minerals, etc. They can be obtained from green vegetables, normal Indian meal of roti/dal/rice, milk, fruits, etc.

21. Maintaining personal hygiene and doing physical exercise is of utmost important to stay fit and healthy.

22. We should avoid drug to avoid physical, mental and emotional ailments.

Class 8 Science Chapter 10 Notes Important Terms

Adam’s apple: At puberty, the voice box or the larynx begins to grow. The growing voice box in boys can be seen as a protruding part of the throat called Adam’s apple.

Adolescence: The period of life, when the body undergoes changes, which leads to reproductive maturity, is called adolescence. It starts around the age of 11 and lasts upto 18 or 19 years of age.

Adrenaline: The hormone produced by adrenals is called adrenaline. It helps the body to adjust to stress when one is very angry, embarrassed and worried.

Balanced diet: A balanced diet or meal is one which includes proteins, vitamins, fats, carbohydrates, minerals, etc., in adequate quantity and proportion.

Chromosomes: These are thread-like structures present inside the nucleus of a cell and helps in for carrying genetic information from one generation to next generation.

Endocrine glands: Different types of hormones are secreted from particular glands called endocrine glands or endocrine system.

Female hormone or estrogen: The female hormone is secreted by ovaries at the onset on puberty and causes development of secondary sexual characters in female.

Growth hormones: Pituitary gland secretes growth hormones which is necessary for the normal growth of a person.

Hormones: Hormones are chemical substances secreted from endocrine glands. They are responsible for regulating metabolic and other activities of the body.

Insulin: The hormone produced by pancreas is called insulin.

Male hormone or testosterone: The male hormone is released by the testes at the onset of puberty and causes changes in secondary sexual characters.

Menarche: The first menstrual flow begins at puberty is known as menarche.

Menopause: When the menstruation ceases, the stage is called menopause.

Menstruation: The process in a woman of discharging blood and other material from the lining of uterus at intervals of about 28-30 days is called menstruation.

Pituitary gland: A pea-sized body attached to the base of the brain that is important in controlling growth and development and functioning of the other endocrine gland.

Puberty: The period of life, during which the human body undergoes several changes and reaches sexual maturity and the human beings become capable of reproduction, is called puberty.

Reproductive health: Good health is essential for adolescence and for reproductive phase of life. For good health one should have a balanced diet, do physical exercises, avoid smoking, drinking and drugs, maintain hygiene and take proper sleep and rest.

Secondary sexual characters: In adolescence period, there are several changes including growth of facial hair, i.e., moustaches and beard on boys’ face, development of breast in girls, etc. These features or characters that help to distinguish the male from the female are called secondary sexual characters.

Sex chromosomes: All human beings have 23 pairs of chromosomes in the nuclei of their cells. Two chro-mosomes out of these are the sex chrmosomes named X and Y. A male has one X and one Y chromosome while a female has two X chromosomes.

Thyroxine: The hormone produced by the thyroid gland is called thyroxine.

 

On this page, you will find Reproduction in Animals Class 8 Notes Science Chapter 9 Pdf free download. CBSE NCERT Class 8 Science Notes Chapter 9 Reproduction in Animals will seemingly help them to revise the important concepts in less time.

CBSE Class 8 Science Notes Chapter 9 Reproduction in Animals

Reproduction in Animals Class 8 Notes Understanding the Lesson

1. Reproduction is the process of continuation of similar kinds of individuals, generation after generation. In this process, all living beings produce their young ones for continuity of life on the planet earth.

2. There are two modes by which animals reproduce. These are:

• Sexual reproduction and
• Asexual reproduction.

3. Reproduction resulting from the fusion of male and female gametes is called sexual reproduction; e.g., frog, fish, cow, human beings, etc., reproduce by sexual reproduction.

4. Reproduction in which young ones are formed from the cells of a single parent and are identical copies of their parents is called asexual reproduction. This type of reproduction is seen in Amoeba, yeast, worms, etc.

5. There are different reproductive organs in male and female. The main reproductive organs in males are testes, sperm ducts, urethra and penis , whereas those in females are ovaries, oviducts, uterus and vagina

6. In male, the testes produce the male gametes called sperms , whereas in female, the ovary produces female gametes called ova (eggs)
In human beings, a single matured egg is released into the oviduct by one of the ovaries every month.

7. Uterus is the part where development of the baby takes place.

8. When sperms come in contact with an egg, one of them may fuse with the egg. Such fusion of egg and the sperm is called fertilisation

9. The nuclei of the sperm and the egg fuse to form a single nucleus forming a fertilised egg called zygote

10. Fertilisation which takes place inside the female body is called internal fertilisation and that in which the fusion of a male and a female gametes takes place outside the female body is called external fertilisation. Internal fertilisation occurs in many animals including humans, cows, dogs and hens whereas external fertilisation is very common in aquatic animals like fish, frogs, starfish, etc.

11. The zygote formed after fertilisation begins to develop into an embryo . The zygote divides repeatedly to give rise to a ball of cells which then begin to form groups that develop into different tissues and organs of the body termed as embryo.

12. The embryo gets embedded in the wall of the uterus for further development.

13. The stage of the embryo in which all the body parts can be identified is called a foetus. When the development of the foetus is complete, the mother gives birth to the baby.

14. The animals which give birth to their young ones are called viviparous animals and those which lay eggs to reproduce are called oviparous animals.

15. The immature free-living form of most invertebrates (animals lacking a backbone) and amphibians and fish which at hatching from the egg is fundamentally unlike its parent and must metamorphose is called larva.

16. The transformation of the larva into an adult through drastic changes is called metamorphosis.

17. In Hydra, new individuals develop from buds. This method of asexual reproduction is called budding.

18. Amoeba reproduces by dividing itself into two. This type of asexual reproduction is called binary fission.

Class 8 Science Chapter 9 Notes Important Terms

Asexual reproduction: The mode of reproduction in which a single organism is able to produce one or more of its kind by itself is known as asexual reproduction; e.g., Amoeba, yeast, Hydra, etc., undergo asexual reproduction.

Binary fission: The type of reproduction in which an animal reproduces by dividing into two individuals is called binary fission; e.g., Amoeba reproduces by dividing itself into two.

Budding: This kind of reproduction is seen in Hydra and yeast. It is the process of reproduction in which new individuals develop as outgrowths from a single parent. The outgrowths developed on parent body is called buds and the process of reproduction is known as budding.

Embryo: When cells produced by the division of the zygote begin to form groups that develop into different tissues and organs of the body is called embryo.

External fertilisation: The fusion of male and female gametes takes place outside the female body. This is called external fertilisation. Most of the aquatic animals undergo this type of fertilisation.

Fertilisation: The process of union of male gametes or sperms and female gametes or ova (egg) is called fertilisation.

Foetus: The stage of the development of embryo in which the development and emergence of the various body parts like the hands, the feet and eyes, etc., can be identified is called the foetus.

Internal fertilisation: The fusion of male and female gametes or fertilisation that takes place inside the female body is called internal fertilisation. All insects, birds and mammals including human beings undergo this type of fertilisation.

Metamorphosis: A biological process in which larva drastically changes into an adult in an invertebrate or amphibian during their life cycle is known as metamorphosis.

Ova or Eggs: Female gametes produced by ovary in female are called ova or eggs.

Oviparous animals: The animals which lay eggs and hatch them to produce their young ones are called oviparous animals; e.g., frog, butterflies, hen, crow, etc.

Reproduction: The process of producing the offspring of one’s own kind for continuity of life in the earth is known as reproduction.

Sexual reproduction: The type of reproduction which involves fusion of male and female gametes is called sexual reproduction.

Sperms: Sperms are the male gametes produced by the testes in male.

Viviparous animals: The animals which give birth to their young ones are called viviparous animals; e.g., cow, buffalo, cat, dog, human beings, etc.

Zygote: The nucleus of the sperms and the egg fuse to form a single nucleus during the process of fertilisation. The fertilised egg is called zygote.

On this page, you will find NCERT Class 10 Economics Chapter 5 Notes Pdf free download. CBSE Class 10 Social Science Notes Economics Chapter 5 SST Consumer Rights will seemingly, help them to revise the important concepts in less time.

Consumer Rights Class 10 Notes Social Science Economics Chapter 5

CBSE Class 10 Economics Chapter 5 Notes Understanding the Lesson

1. People participate in the market both as producers and consumers. As producers of goods and services they could be working in any of the sectors. As consumers they participate in the market when they purchase goods and services that they need.

2. Rules and regulations are required for the protection of the consumers in the market place because markets do not work in a fair manner. Producers are few and powerful whereas consumers purchase in small amounts and are scattered. At times false information is passed on through the media, and other sources to attract consumers.

3. The consumer movement arose out of dissatisfaction of the consumers as many unfair practices were being indulged in by the sellers. There was no legal system available to consumers to protect them from exploitation in the market place.

4. In India, consumer movement originated slowly and steadily. Till the 1970s, consumer organizations were largely engaged in writing articles and holding exhibitions. They formed consumer groups to look into the malpractices in ration shops. Gradually, the number of consumer groups increased in the country.

5. The movement got success in creating pressure on business firms as well as government to correct business conduct. In 1986, the Indian government enacted the Consumer Protection Act, popularly known as COPRA.

6. As consumers, we have the right to be protected against the marketing of goods and delivery of services that are hazardous to life and property. Producers need to strictly follow the required safety rules and regulations because safety is everyone’s right.

7. Consumers have the right to be informed about the particulars of goods and services that they purchase. They can then complain and ask for compensation or replacement if the product proves to be defective in any manner.

8. In recent times, the consumers’ right to information has been expanded to cover various services provided by the Government. In October 2005, the Government of India enacted a law, known as Right to Information Act. The law ensures its citizens all the information about the functions of government departments.

9. Consumers have the right to choose whether to continue to receive the service. Consumers have also the right to seek redressal against unfair trade practices and exploitation. If any damage is done to a consumer, he/she has the right to get compensation depending on the degree of damage.

10. Consumer Forums or Consumer Protection Council guide consumers on how to file cases in the consumer court. On many occasions, they also represent individual consumers in the consumer courts.

11. Under COPRA, three-tier quasi-judicial machinery at the district, state and national levels was set up for redressal of consumer disputes. If a case is dismissed in district level court, the consumer can also appeal in state and then in national-level courts.

12. The Consumer Protection Act or COPRA has enabled consumers to have the right to represent in the consumer courts. The enactment of this Act has led to the setting up of separate departments of Consumer Affairs in central and state governments.

13. India has been observing 24 December as the National Consumer’s Day. India is one of the countries that have exclusive courts for consumer redressal.

14. The consumer redressal process is becoming difficult, expensive and time-consuming. The existing laws also are not very clear on the issue of compensation to consumers injured by defective products.

15. After more than 25 years of the enactment of COPRA, consumer awareness in India is spreading but slowly. It is rightly said that consumer movements can be effective only with the consumers’ active involvement.

Consumer Rights Class 10 CBSE Notes Important Terms

Consumer: A person who buys things or uses services.

Adulterated: Impure.

Producer: A person, company or country that makes or grows something.

Rampant: Existing or spreading everywhere in a way that is very difficult to control.

Compensation: Money that you pay to somebody because you have injured him/her or lost or damaged his/her property.

Redressal: Compensation for injuries sustained.

Cumbersome: Large or heavy and therefore, difficult to carry or use.

Enactment: The process of passing legislation.

On this page, you will find NCERT Class 10 Civics Chapter 8 Notes Pdf free download. CBSE Class 10 Social Science Notes Civics Chapter 8 SST Challenges to Democracy will seemingly, help them to revise the important concepts in less time.

Challenges to Democracy Class 10 Notes Social Science Civics Chapter 8

CBSE Class 10 Civics Chapter 8 Notes Understanding the Lesson

1. Democracy is a dominant form of government in the contemporary world. But the promise of democracy is far from realised anywhere in the world.

2. Although democracy does not have a challenger, that does not mean that it does not face any challenges. Different countries face different kinds of challenges.

3. The countries not under democratic government face the foundational challenge of making the transition to democracy and then instituting democratic government.

4. Most of the established democracies face the challenge of expansion. This involves applying the basic principle of democratic government across all the regions, different social groups and various institutions.

5. The third challenge of deepening of democracy is faced by every democracy in one form or another. This involves strengthening of the institutions and practics of democracy.

6. Each of the above challenges is linked to the possibility of reforms. Since all the countries do not have the same challenges, so they cannot follow the same recipe of political reforms.

7. When we talk in the context of our country, we can develop some proposals for reforms at the national level. But the real challenge of reforms may not lie at the national level. Some of the crucial questions need to be thought at the state or local level.

8. While devising ways and means for political reforms in India, some broad guidelines should be kept in mind; for example, legal ways of reforming politics. Carefully devised changes in law can help to discourage wrong political practices and encourage good ones. But legal constitutional changes by themselves cannot overcome challenges to democracy. In fact, democratic reforms are to be carried out mainly by political activists, parties, movements and politically conscious citizens.

9. Those laws are good which empower people to carry out democratic reforms. The Right to Information Act empowers the people to find out what is happening in government and act as watchdogs of democracy.

10. Democratic reforms are to be brought about principally through political practice. Therefore, the main focus of political reforms should be on ways to strengthen democratic practice.

11. Any proposal for political reforms should think not only about what is a good solution but also about who will implement it and how.

Challenges to Democracy Class 10 CBSE Notes Important Terms

Challenge: A difficulty that carries within it an opportunity for progress.

Foundational: Denoting an underlying basis or principle.

Guideline: A general rule, principle, or piece of advice.

Watchdog: A person or group of persons that acts as a protector or guardian against inefficiency, illegal practices, etc.

Reform: The action or process of reforming an institution or practice.

On this page, you will find NCERT Class 10 Civics Chapter 5 Notes Pdf free download. CBSE Class 10 Social Science Notes Civics Chapter 5 SST Popular Struggles and Movements will seemingly, help them to revise the important concepts in less time.

Popular Struggles and Movements Class 10 Notes Social Science Civics Chapter 5

CBSE Class 10 Civics Chapter 5 Notes Understanding the Lesson

1. Power-sharing is important in a democracy and different tiers of government and various social groups share power. Those who exercise power are constrained by the influence and pressure exerted on them.

2. Democracy involves conflict of interests and viewpoints. These differences are often expressed in organized ways. Those who are in power are required to balance these conflicting demands and pressures.

3. Struggles around conflicting demands and pressures shape democracy. Various pressure groups and movements influence politics using indirect ways.

4. The popular struggles in Nepal and Bolivia are two examples in this regard which were made successful with the help of organizations like Seven Party Alliance (SPA) and FEDECOR respectively.

5. The movement in Nepal was to establish democracy while the struggle in Bolivia involved claims on an elected, democratic government. Both these struggles were successful but their impact was at different levels.

6. There are many indirect ways in which people can get governments to listen to their demands or their points of view. They could do so by forming an organization and undertaking activities to promote their interests or their viewpoints. These are called interest groups or pressure groups.

7. Pressure groups influence government policies. They do not aim to directly control or share political power.

8. Movements too attempt to influence politics rather than directly take part in electoral competition; for example, Narmada Bachao Andolan, Movement for Right to Information, etc.

9. Interest groups seek to promote the interests of a particular section or group of society; for example, Trade Unions, Business Associations, etc. Their chief concern is the betterment and well-being of their members, not society in general.

10. Narmade Bachao Andolan is a good example of a single-issue movement. It can be contrasted with movements like environmental movement and women’s movement that are long term and involve more than one issue.

11. Pressure groups and movements exert influence on politics in a variety of ways-by carrying out information campaigns, organizing meetings, filing petitions, etc. They also organise protest activity like strikes or disrupting government programmes.

Note: Please note as per the CBSE curriculum 2017-18, chapter-5 has to be done as project work only and will not be evaluated in theory.

Popular Struggles and Movements Class 10 CBSE Notes Important Terms

Maoists: Those communists who believe in the ideology of Mao, the leader of the Chinese Revolution. They seek to overthrow the government through an armed revolution so as to establish the rule of the peasants and workers.

Ultimatum: A final demand, with a threat of hostile action if this is rejected.

Mobilisation: Act of marshalling and organising and making ready for use or action.

Pressure group: A group of people having common interests which exert pressure on the government for fulfilment of their interests.

Movement: A loose organisation which depends on spontaneous mass participation.

On this page, you will find NCERT Class 10 Civics Chapter 3 Notes Pdf free download. CBSE Class 10 Social Science Notes Civics Chapter 3 SST Democracy and Diversity will seemingly, help them to revise the important concepts in less time.

Democracy and Diversity Class 10 Notes Social Science Civics Chapter 3

CBSE Class 10 Civics Chapter 3 Notes Understanding the Lesson

1. Language and region are not the only features that give a distinct identity to people. Sometimes, people also identify themselves on the basis of their physical appearance, class, religion, gender, caste, tribe, etc.

2. In 1968 Olympics held at Mexico City, Tommie Smith and John Carlos, both African-Americans, won the gold and bronze medals respectively in 200 metres race. In the medal ceremony they received their medals wearing black socks and no shoes to represent black poverty. They did so because they wanted to draw international attention to racial discrimination in the United States.

3. The International Olympic Association held Carlos and Smith guilty of violating the Olympic spirit by making a political statement. Their medals were taken back. But their action gained international attention for the Civil Rights Movement in the US.

4. The athletes in the above example responded to social divisions and social inequalities which exist in almost all societies. Social diversity can take different forms in different societies.

5. Some social differences are based on accident of birth and some are based on our choices. But every social difference does not lead to social division. Social differences divide similar people from one another but they also unite very different people.

6. People belonging to different social groups share differences and similarities cutting across the boundaries of their groups. We all have more than one identity and can belong to more than one social group.

7. Social division takes place when some social difference overlaps with other differences. The difference between the Blacks and Whites becomes a social division in the US because Blacks are poor and discriminated against. In our country Dalits face discrimination and injustice. Situation of this kind produces social divisions.

8. If social differences cross cut one another, it is difficult to pit one group of people against the other. It means that groups that share a common interest on one issue are likely to be in different sides on a different issue.

9. Overlapping social differences create possibilities of deep social divisions and tensions. Cross-cutting social differences are easier to accommodate. Social divisions of one kind or another exist in most countries. It does not matter whether the country is small or big.

10. The combination of politics and social divisions is very dangerous. The competition among various political parties tends to divide any society. If they start competing in terms of some existing social divisions, it can make social divisions into political divisions and lead to conflict and tension in the country. So politics and social divisions must not be allowed to mix.

11. But every expression of social divisions in politics does not lead to disasters. Social divisions of one kind or another exist in most countries of the world. Wherever they exist, these divisions are reflected in politics.

18. Social divisions affect voting in most countries. People from one community tend to prefer some party more than others. But this does not lead to disintegration of the country.

19. Three factors that determine the outcomes of politics of social divisions are- how people perceive their identities, how political leaders raise the demands of any community and how the government reacts to demands of different groups.

20. The assertion of social diversities in a country need not be seen as a source of danger. In a democracy, political expression of social divisions can be healthy. This allows various disadvantaged and marginal social groups to express their grievances and get the government to attend to these.

21. But these people need to fight against the injustices. Such a fight often takes the democratic path, voicing their demands in a peaceful and constitutional manner and seeking a fair position through elections. Sometimes the struggle against inequalities takes the path of violence. However, democracy is the best way to fight for recognition.

Democracy and Diversity Class 10 CBSE Notes Important Terms

African-American: Descendants of Africans who were brought into America as slaves between the 17th century and early 19th century.

Homogeneous society: A society that has similar kinds of people, especially where there are no significant ethnic differences.

Migrant: Anybody who shifts from one region or country to another region within a country or to another country, usually for work or other economic opportunities.

Outcome: The result of an event.

Racism: A belief in the superiority of a particular race.

On this page, you will find Playing with Numbers Class 8 Notes Maths Chapter 16 Pdf free download. CBSE NCERT Class 8 Maths Notes Chapter 16 Playing with Numbers will seemingly help them to revise the important concepts in less time.

CBSE Class 8 Maths Chapter 16 Notes Playing with Numbers

Playing with Numbers Class 8 Notes Conceptual Facts

1. Generalised form of a two-digit number if a is ten place digit and 6 is unit place digit.
a x 10 + b x 1 = 10a + b

2. Generalised form of a three-digit number if a is ten place digit and b is unit place digit.
a x 100 + b x 10 + c x 1 = 100a + 10b+ c

3. Two-digit original numbers = 10a + b
Number obtained by reversing the digits = 10b + a
Sum = 10a + b + 10b + a
= 11a + 11b – 11(a + b)

which is divisible by 11.
Difference = (10a + b) – (10b + a)
= 10a + 6 – 106 – a
= 9a -9b – 9(a – b)
which is divisible by 9.

4. Three-digit original number if a is hundred place digit and 6 is ten place digit and c is unit place digit.
= 100a + 10b + c
The number obtained by reversing the digits = 100c + 10b + a
Difference = (100a + 10b + c) – (100c + 10b + a)
= 100a + 10b + c – 100c – 10b – a
= 99a – 99c = 99(a – c)
which is divisible by 99.

5. Divisibility test by 2 – A number is divisible by 2 if its unit place is even.
For example: 24, 48, 56 and 76 etc.

6. Divisibility test by 3 – A number is divisible by 3 if the sum of all digits of the given number is also divisible by 3.
For example: 123 = 1 + 2 + 3 = 6÷3 = 2
528 = 5 + 2 + 8 = 15 ÷ 3 = 5

7. Divisibility test by 5 – If the unit place digit is either 0 or 5 then it is divisible by 5.

8. Divisibility test by 9 – A number is divisible by 9 if the sum of its digits is also divisible by 9.
For example:
225 =2+2+5=9÷ 9=1
684 = 6 + 8 + 4 = 18 ÷ 9 = 2

9. Letters for digits – There are two rules followed while doing such puzzles.

• The first digit cannot be zero.
• Each letter in the puzzle must stand for just one digit.

On this page, you will find Introduction to Graphs Class 8 Notes Maths Chapter 15 Pdf free download. CBSE NCERT Class 8 Maths Notes Chapter 15 Introduction to Graphs will seemingly help them to revise the important concepts in less time.

CBSE Class 8 Maths Chapter 15 Notes Introduction to Graphs

Introduction to Graphs Class 8 Notes Conceptual Facts

• XOX’ and YOY’ taken together are called coordinate axes.
• The plane containing the coordinate axes is called cartesian plane.
• The point of intersection of the coordinate axes is called origin.
• The x-coordinate is always written before y-coordinate e.g., if 2 is x-coordinate and 3 is y-coordinate, then the coordinates are (2, 3).
  
• The x-coordinate of a point lying on y-axis is zero.
• The y-coordinate of a point lying on x-axis is zero.
• The x-coordinate is also called abscissa and y-coordinate ordinate.

 

 

On this page, you will find Factorisation Class 8 Notes Maths Chapter 14 Pdf free download. CBSE NCERT Class 8 Maths Notes Chapter 14 Factorisation will seemingly help them to revise the important concepts in less time.

CBSE Class 8 Maths Chapter 14 Notes Factorisation

Factorisation Class 8 Notes Conceptual Facts

• Prime factors of 30 (say) = 2 x 3 x 5
• Factors of algebraic expression 4xy = 4 x x x y
• 1 is a factor of every expression.
• Method of common factors
• 4x + 24 = 4(x + 6)
• Method of factorisation by regrouping terms
  6xy + 3y = 2 x 3 x x x y + xy = 3 xy (2x + 1) = 3y (2x + 1)

Factorisation using identities
a² + 2ab + b²– (a + b)²
a² – 2ab + b²= (a-b)²
a² – b² = (a + b) (a – b)