Class 10 NCERT Chapters

We face a dilemma: democracy is seen to be good in principle, but felt to be not so good in its practice. This dilemma invites us to think hard about the outcomes of democracy.

A political party is a group of people who come together to contest elections and hold power in the government. They agree on some policies and programmes for the society with a view to promote the collective good. Parties reflect fundamental political divisions in a society.

The existence of social diversity does not threaten democracy. Political expression of social differences is possible and sometimes quite desirable in a democratic system. Three kinds of social differences that can take the form of social divisions and inequalities are social differences based on gender, religion and caste.

Vertical division of power among different levels of government is one of the major forms of power-sharing in modern democracies. It is most commonly referred to as federalism.

In a democracy, all power does not rest with any one organ of the government. An intelligent sharing of power among legislature, executive and judiciary is very important to the design of a democracy.

It is difficult for us to imagine a world without printed matter. We find evidence of print everywhere around us – in books, journals, newspapers, prints of famous paintings, and also in everyday things like theatre programmes, official circulars, calendars, diaries, advertisements, cinema posters at street corners. We read printed literature, see printed images, follow the news through newspapers, and track public debates that appear in print.

In 1900, a popular music publisher E.T. Paull produced a music book that had a picture on the cover page announcing the ‘Dawn of the Century’. At the centre of the picture is a goddess-like figure, the angel of progress, bearing the flag of the new century. She is gently perched on a wheel with wings, symbolising time.

When we talk of ‘globalisation’ we often refer to an economic system that has emerged since the last 50 years or so. But as you will see in this chapter, the making of the global world has a long history - of trade, of migration, of people in search of work, the movement of capital, and much else. As we think about the dramatic and visible signs of global interconnectedness in our lives today, we need to understand the phases through which this world in which we live has emerged.

As you have seen, modern nationalism in Europe came to be associated with the formation of nation-states. It also meant a change in people’s understanding of who they were, and what defined their identity and sense of belonging. New symbols and icons, new songs and ideas forged new links and redefined the boundaries of communities. In most countries the making of this new national identity was a long process. How did this consciousness emerge in India?

In 1848, Frédéric Sorrieu, a French artist, prepared a series of four prints visualising his dream of a world made up of ‘democratic and social Republics’, as he called them. The first print of the series, shows the peoples of Europe and America - men and women of all ages and social classes - marching in a long train, and offering homage to the statue of Liberty as they pass by it.

A major step taken in 1986 by the Indian government was the enactment of the Consumer Protection Act 1986, popularly known as COPRA.

Globalisation is the process of rapid integration of countries. This is happening through greater foreign trade and foreign investment. MNCs are playing a major role in the globalisation process.

In a barter system where goods are directly exchanged without the use of money, double coincidence of wants is an essential feature. In contrast, in an economy where money is in use, money by providing the crucial intermediate step eliminates the need for double coincidence of wants.

When we produce a good by exploiting natural resources, it is an activity of the primary sector. Since most of the natural products we get are from agriculture, dairy, fishing, forestry, this sector is also called agriculture and related sector.

Different persons can have different developmental goals. What may be development for one may not be development for the other. It may even be destructive for the other.

We use different materials and services in our daily life. Some of these are available in our immediate surroundings, while other requirements are met by bringing things from other places.

Production of goods in large quantities after processing from raw materials to more valuable products is called manufacturing.

We use different things in our daily life made from metal. Various metals are extracted from minerals after proper refinement. Minerals are an indispensable part of our lives.

India is an agriculturally important country. Two-thirds of its population is engaged in agricultural activities. Agriculture is a primary activity, which produces most of the food that we consume. Besides food grains, it also produces raw material for various industries.

Three-fourth of the earth's surface is covered with water, but only a small proportion of it accounts for freshwater that can be put to use. This freshwater is mainly obtained from surface run off and ground water that is continually being renewed and recharged through the hydrological cycle.

Biodiversity or Biological Diversity is immensely rich in wildlife and cultivated species, diverse in form and function but closely integrated in a system through multiple network of interdependencies.

Everything available in our environment which can be used to satisfy our needs, provided, it is technologically accessible, economically feasible and culturally acceptable can be termed as Resource.

The various components of an ecosystem are interdependent. The producers make the energy from sunlight available to the rest of the ecosystem. There is a loss of energy as we go from one trophic level to the next, this limits the number of trophic levels in a food-chain.

A compass needle is a small magnet. Its one end, which points towards north, is called a north pole, and the other end, which points towards south, is called a south pole. A magnetic field exists in the region surrounding a magnet, in which the force of the magnet can be detected.

A stream of electrons moving through a conductor constitutes an electric current. Conventionally, the direction of current is taken opposite to the direction of flow of electrons. The SI unit of electric current is ampere.

The ability of the eye to focus on both near and distant objects, by adjusting its focal length, is called the accommodation of the eye. The smallest distance, at which the eye can see objects clearly without strain, is called the near point of the eye or the least distance of distinct vision. For a young adult with normal vision, it is about 25 cm.

Light seems to travel in straight lines. Mirrors and lenses form images of objects. Images can be either real or virtual, depending on the position of the object.

Variations arising during the process of reproduction can be inherited. These variations may lead to increased survival of the individuals. Sexually reproducing individuals have two copies of genes for the same trait. If the copies are not identical, the trait that gets expressed is called the dominant trait and the other is called the recessive trait.

Reproduction, unlike other life processes, is not essential to maintain the life of an individual organism. Reproduction involves creation of a DNA copy and additional cellular apparatus by the cell involved in the process.

Control and coordination are the functions of the nervous system and hormones in our bodies. The responses of the nervous system can be classified as reflex action, voluntary action or involuntary action.

Movement of various types can be taken as an indication of life. Maintenance of life requires processes like nutrition, respiration, transport of materials within the body and excretion of waste products.

Carbon is a versatile element that forms the basis for all living organisms and many of the things we use. This large variety of compounds is formed by carbon because of its tetravalency and the property of catenation that it exhibits.

Elements can be classified as metals and non-metals. Metals are lustrous, malleable, ductile and are good conductors of heat and electricity. They are solids at room temperature, except mercury which is a liquid. Metals can form positive ions by losing electrons to non-metals.

Acid-base indicators are dyes or mixtures of dyes which are used to indicate the presence of acids and bases. Acidic nature of a substance is due to the formation of H⁺ (aq) ions in solution. Formation of OH^– (aq) ions in solution is responsible for the basic nature of a substance.

A complete chemical equation represents the reactants, products and their physical states symbolically. A chemical equation is balanced so that the numbers of atoms of each type involved in a chemical reaction are the same on the reactant and product sides of the equation. Equations must always be balanced.

In Class IX, you have studied about experimental (or empirical) probabilities of events which were based on the results of actual experiments. Experimental probabilities are based on the results of actual experiments and adequate recordings of the happening of the events.

In this chapter, you will study how to measure mean, median and mode of grouped data. You will also learn the concept of cumulative frequency, the cumulative frequency distribution and how to draw cumulative frequency curves, called ogives.

In this chapter, you will study how to determine the surface area of an object formed by combining any two of the basic solids - cuboid, cone, cylinder, sphere and hemisphere.

Many objects that we come across in our daily life are related to the circular shape in some form or the other. Cycle wheels, wheel barrow (thela), dartboard, round cake, papad, drain cover, various designs, bangles, brooches, circular paths, washers, flower beds. are some examples of such objects.

A circle is a collection of all points in a plane which are at a constant distance (radius) from a fixed point (centre).

Trigonometry is one of the most ancient subjects studied by scholars all over the world. Trigonometry was invented because its need arose in astronomy. Since then the astronomers have used it, for instance, to calculate distances from the Earth to the planets and stars.

The word ‘trigonometry’ is derived from the Greek words ‘tri’ (meaning three), ‘gon’ (meaning sides) and ‘metron’ (meaning measure). trigonometry is the study of relationships between the sides and angles of a triangle.

To locate the position of a point on a plane, you require a pair of coordinate axes. The distance of a point from the y-axis is called its x-coordinate, or abscissa. The distance of a point from the x-axis is called its y-coordinate, or ordinate.

Two figures having the same shape but not necessarily the same size are called similar figures. All the congruent figures are similar but the converse is not true.

An arithmetic progression is a list of numbers in which each term is obtained by adding a fixed number to the preceding term except the first term.

One type of polynomial is the quadratic polynomial of the form ax² + bx + c, a ≠ 0. When you equate this polynomial to zero, you get a quadratic equation. Quadratic equations come up when you deal with many real-life situations.

An equation which can be put in the form ax + by + c = 0, where a, b and c are real numbers, and a and b are not both zero, is called a linear equation in two variables x and y. Solution of such an equation is a pair of values, one for x and the other for y, which makes the two sides of the equation equal.

If p(x) is a polynomial in x, the highest power of x in p(x) is called the degree of the polynomial p(x). For example, 4x + 2 is a polynomial in the variable x of degree 1, 2y² - 3y + 4 is a polynomial in the variable y of degree 2.

Euclid’s division algorithm, as the name suggests, has to do with divisibility of integers. Stated simply, it says any positive integer a can be divided by another positive integer b in such a way that it leaves a remainder r that is smaller than b.

Mother Goose is a well-known book of nursery rhymes in English. Do you think such a book can save Planet Earth from a Martian invasion?