Articles

1. How did Richard Ebright excite the scientific world at the age of twenty two?

Richard Ebright was just twenty-two when he ‘excited’ the scientific world with a new theory. It was on how cells worked. Ebright and his college room- mate explained the theory in an article in the ‘Proceedings of the National Academy of Science’. It was the first time that this famous scientific journal had ever published the work of college students.

1. Why were the two boys surprised and fascinated?

The two boys were highly surprised. They saw fresh muddy imprints of a pair of bare feet. They wondered what a barefooted man doing on the steps of a house in the middle of London. They saw only the footsteps but didn’t see the man whose marks they were. As they gazed, a fresh foot mark appeared from nowhere. The boys followed them fascinated. The marks became fainter and disappeared altogether.

1. Who was Horace Danby?

Horace Danby was about fifty years old and unmarried. Everyone thought that he was a good and honest citizen. He lived with a housekeeper who worried about his health. He suffered from the attacks of hay fever in summer. He made locks and was successful at his business. But he was not completely honest. He robbed a safe once a year to buy rare and costly books.

1. Why did Hari Singh think that Anil’s job was queer?

Anil contributed to magazines. He wrote for a living. He didn’t earn much. Nor did he have a regular income. He couldn’t afford to have a servant. So it was difficult for Hari Singh to understand his profession.

"The Hundred Dresses - II" is the sequel to the chapter "The Hundred Dresses - I" in the Class 10 English textbook. It continues the story of Wanda Petronski and explores the consequences of bullying and the power of remorse and forgiveness.

"The Hundred Dresses - I" is a chapter from the Class 10 English textbook that tells the story of a young girl named Wanda Petronski who faces bullying and prejudice in school. The chapter explores themes of empathy, kindness, and the impact of our words and actions on others.

This is a story about a beggar Lushkoff who used to beg posing as a school teacher or a student. He meets an advocate Sergei who offers him a job at his house.

This story reflects the challenges of being a teenager, and the problems of growing up. The narrator in this story is a teenager who finds it difficult to make new friends and adjust to a new place. He feels lonely and depressed. But soon his misconceptions about people are removed.

The story ‘The Last Leaf’ is a story of supreme sacrifice by an old artist. The old artist Behrman paints a masterpiece to keep someone’s hopes and willpower alive. He dies in this good cause. His sacrifice fulfils his ambition of creating a masterpiece too. Johnsy and Sue were two young artists.

This story is a true account of the devastation brought about in Orissa (now Odisha) in 1999 by a super cyclone. On 27th October 1999, Prashant, a young boy of 19, went to Ersama to his friend’s house. Ersama is a small town in coastal Orissa which is eighteen kilometres from village.

This is the story of the statue of a prince and a little swallow who, in order to help the poor, sacrificed their lives. There was the statue of a prince called the Happy Prince standing on a tall pillar high above the city.

It is the story of a kingdom where the king and his minister both were idiots. They had ordered that the night be treated as day and all the people should work only after dark. They should go to bed as soon as the sun came up. The king’s orders were followed by the people for fear of death. This delighted the king and his minister.

Mehendra was a junior supervisor in a firm which offered on hire supervisors at different sites. He was a bachelor. A cook, Iswaran,ss was attached to him. Iswaran cooked for him, washed his clothes and performed other household chores.

The narrator’s grandfather loved animals. He had his own private zoo. He bought a baby monkey from a tonga-driver and named it Toto. He wanted Toto to add to his collection for the zoo. The narrator’s grandmother did not like his pets. So, Toto’s presence was kept a secret.

This story highlights a child’s love for his parents. It is the festival of spring. Everyone is going to a fair. The child is very happy and excited because he is also going to the fair with his parents. On the way to the fair, the child is fascinated by the natural beauty. He enjoys every moment.

Preparing for a trip is sometimes more fun than the trip itself. In this story, the author and his friends, George and Harris, are packing for a trip. It is a humorous story. The humour lies in the funny actions of the author and his friends.

Dr. Kalam in his autobiography tells us about his childhood. One of the world’s greatest scientists. Dr. Kalam was born it to a middle-class Muslim family in 1931 at Rameswaram. His journey from a middle-class family in Rameswaram to the President’s House was not a smooth one.

"The Snake and the Mirror" is a frightening tale told in a humorous way. The story has been written by V.M. Basheer, a well-known Malayalam writer. The incident in the story is both humorous and frightening. It also has a surprise ending.

Albert Einstein was born on March 14, 1879, in the German city of Ulm. He had a large head and his mother thought that he was a freak. He was a late talker. He could never adjust with his playmates who used to call him ‘Brother Boring.’

All fathers are not alike. Some show their love and affection for their children and play with them. Others also love and care for their children but they show it by working hard for them and giving them instructions and advice.

Evelyn Glennie is a multi-percussionist. She can play about one thousand instruments with perfection. She listens to sound without hearing it! She fought against a physical disability and became a source of inspiration for thousands of disabled persons.

The concept of set serves as a fundamental part of the present day mathematics. Today this concept is being used in almost every branch of mathematics. Sets are used to define the concepts of relations and functions. The study of geometry, sequences, probability requires the knowledge of sets.

In earlier classes, we studied about the concept of probability as a measure of uncertainty of various phenomenon. We have obtained the probability of getting an even number in throwing a die as 3/6 or 1/2. Here the total possible outcomes are 1,2,3,4,5 and 6 (six in number).

Statistics deals with data collected for specific  purposes. We can make decisions about the data by analysing and interpreting it.

Calculus is that branch of mathematics which mainly deals with the study of change in the value of a function as the points in the domain change.

To locate the position of a point in a plane, we need two intersecting mutually perpendicular lines in the plane. These lines are called the coordinate axes and the two numbers are called the coordinates of the point with respect to the axes.

In this Chapter, we will study about some curves - circles, ellipses, parabolas and hyperbolas. The names parabola and hyperbola are given by Apollonius. These curves are in fact, known as conic sections or more commonly conics because they can be obtained as intersections of a plane with a double napped right circular cone.

Amines can be considered as derivatives of ammonia obtained by replacement of hydrogen atoms with alkyl or aryl groups.

Carbohydrates are optically active polyhydroxy aldehydes or ketones or molecules which provide such units on hydrolysis. They are broadly classified into three groups - monosaccharides, disaccharides and polysaccharides.

A solution is a homogeneous mixture of two or more substances. Solutions are classified as solid, liquid and gaseous solutions. The concentration of a solution is expressed in terms of mole fraction, molarity, molality and in percentages.

Two-dimensional coordinate geometry is a combination of algebra and geometry. A systematic study of geometry by the use of algebra was first carried out by celebrated French philosopher and mathematician René Descartes, in his book ‘La Géométry, published in 1637.

In mathematics, the word, "sequence" is used in much the same way as it is in ordinary English. When we say that a collection of objects is listed in a sequence, we usually mean that the collection is ordered in such a way that it has an identified first member, second member, third member and so on.

An electrochemical cell consists of two metallic electrodes dipping in electrolytic solution(s). Thus an important component of the electrochemical cell is the ionic conductor or electrolyte.

Suppose you have a suitcase with a number lock. The number lock has 4 wheels each labelled with 10 digits from 0 to 9. The lock can be opened if 4 specific digits are arranged in a particular sequence with no repetition. Some how, you have forgotten this specific sequence of digits.

Aldehydes, ketones and carboxylic acids are some of the important classes of organic compounds containing carbonyl group. These are highly polar molecules. Therefore, they boil at higher temperatures than the hydrocarbons and weakly polar compounds such as ethers of comparable molecular masses.

Measurement is a process of comparing a physical quantity with a standard quantity. The standard quantity used to compare a physical quantity for its measurement is called unit.

Anything that has mass and occupies space is matter. There are three different physical states of matter in which a substance can exist - solid, liquid and gas.

According to law of constant proportions, a sample of a pure substance always consists of the same elements combined in the same proportion by mass.

A chemical equation is a shorthand description of a reaction. It symbolically represents the reactants, products and their physical states.

History is an account of events that have happened in the past. It is about the real people and the real things. It does not deal with mere ideas and ideals or what should have been. On the other hand, it is a study of what has been.

History is the study of past events. It helps us to understand those processes that enabled the early humans to successfully conquer their environment and develop the present-day civilization. It is an analysis of society, economy and cultural trends over a long period as reflected in available sources.

There was transformation of European Society after the downfall of the Roman Empire, and the birth of a new religion called Islam which led to the founding of a vast empire that originated in West Asia and spread out over a large part of the world.

The rulers who ruled substantial parts of the North India between AD 1200 to AD 1526 were termed as Sultans and the period of their rule was known as the Delhi Sultanate. These were the Mamluks who were popularly known as the slave dynasty, the Khaljis, the Tughlaqs, the Sayyids and the Lodis.

With the decline of feudalism, the restrictions on peasants become a thing of the past. Simultaneously, the period witnessed the rise of powerful merchant class, which financed discoveries of new lands. These, with other factors, brought about the Industrial revolution which led a sea change throughout the world. This was the beginning of the Modern Age.

There was a very strong dissatisfaction with political leadership and people started demanding more participation in the affairs of the State. Political awareness, ideas like liberty, equality and fraternity were popularised by the printing press.

Industrial Revolution brought social and economic changes that transformed the agricultural society to a modern industrial society. The industrialised nations needed raw materials for their industries as well as markets for their finished good.

Industrialisation, Colonialism and Imperialism created intense rivalry among the European nations over their possessions of colonies in Asia and Africa. This competition became more acute by the end of the 19th century when colonies were no longer available in Asia and Africa.

British Rule had a tremendous effect on Indian society, economy and culture. It also gave rise to a sense of nationhood and a spirit of Nationalism arose which resulted in National Awakening and a feeling of revolt against Britishers.

In the first half of 19^th century the society was backward due (i) lack of education and (i) subordination of women. This prevented society's progress. Many reformers came up during this period who contributed to religious and social awakening helped in transforming the society for betterment.

Exploitation of natural and human resources by British led to rise of Popular Resistance Movements mainly by Peasants, Tribals and Sainiks. The most important Popular Resistance to the British rule during the 19th century was the revolt of 1857. There was a sense of self confidence that gave an impact to National Awakening.