7th Class

Introduction. India in the past, was always ruled by foreign powers. However, after getting independence in 1947, India struggled a lot to stand 00 its feet. As days passed, India emerged a strong nation. It always had  the feeling to become nuclear powered. Steps towards becoming N-powered. When the India-US civil nuclear cooperation agreement was being processed the main focus was Ml India liberating itself from the technology apartheid to which it had been subjected since its first Pokhran nuclear test in 1974. In the beginning (his technology was denied to India by the unconditional waiver  of the guidelines of the Nuclear Suppliers Group (NSG). Many countries did not   India to be N-powered. Australia was the first among them. In India too, the opposition parties made a hue and cry. They did not want the ruling party to sign the agreement as made by the NSGs. The Riling government was more...

A snake is a crawling creature. It is a reptile. We are very familiar with snakes. People are very afraid of snakes because many of them are poisonous. However, all of them are not poisonous. Snakes crawl along the ground on their bellies and breasts. They live both on land and water. There are rough scales on the lower portion of their body. A snake looks like a rope and is of different sizes and colours. The boa and python are very big snakes. Snakes live in holes in the ground or tree-holes and in bushes. They feed on fishes, frogs, insects, rats and young birds. Poisonous snakes like the cobra are really very harmful to man. The bite of these snakes means certain death. Thousands of people die from snake bites every year in our country. When they bite, they inject poison through two hollow long teeth that rest more...

Books are a great source of knowledge to man. I am lover of books. I spend most of my spare time in reading. I like to read books on all branches of literature. But I love to read novels most of all. It helps me to learn new words and also help me to gain knowledge regarding the field of literature. I began to read novel at a very young age. I have read the novels written by R.K. Narayan, Mulkh Raj Anand, Khushwant Singh, Mrs. Nayantara Sehgal and Raja Rao. After reading books written by Indian writers in English, I have also read different English novelists like Henry Fielding, Oliver  Goldsmith, Jane Austen, Charles Dickens, Hardy and Somersat Maugham. I have also read a few American authors. I have found these writers interesting in their own way. It is difficult for me to point out the merits and demerits more...

"An enormous amount of water is thrown out... by means of a trifling amount of labor."   Diodorus siculus, historian The Archimedes screw was first mentioned in the writings of Athenaeus of Naucratis in 200 B.C.E. He described the use of a screw mechanism to extract bilge water from a ship named Syracusia, and attributed its invention to Archimedes. Archimedes (c. 287-212 B.C.E.) himself lived in Syracuse, Sicily, and was devoted to the exploration of mathematics and science. The polymath is thought to have spent time studying in Egypt, and the screw named for him is used in the Nile delta to this day, more than 2,000 years later, as a means to raise water from rivers for irrigation purposes. The Archimedes screw consists of a helix within a hollow tube, the lower end of which is placed in a fluid. The screw is then rotated and the fluid is more...

In mathematics a combination is a way of selecting several things out of a larger group, where (unlike permutations) order does not matter. In smaller cases it is possible to count the number of combinations. For example given three fruit, say an apple, orange and pear, there are three combinations of two that can be drawn from this set: an apple and a pear; an apple and an orange; or a pear and an orange. More formally a k-combination of a set S is a subset of k distinct elements of S. If the set has n elements the number of k-combinations is equal to the binomial coefficient          which can be written using factorials as   more...

Science has revolutionized our life. It has considerably altered the world by its wonderful discoveries and inventions. It has created mysteries. No aspect of our life remains untouched of science, whether at home or in school or in office. It is predominant in every walk of life. It has done not only concrete services to mankind but also filled us with wonder by making impossible things possible for us. Thus it is science which has make helpless man the king of the universe, removed the darkness of ignorance with light of knowledge and changed Our thorny life into the bed of roses. Science has been a potent factor to shape the history of man's civilization on earth. Our forefathers lived a nomadic life, and we are now living in the atomic age. This long leap from the jungle to the atomic civilization could be possible only through science. It is more...

Possibly in 1834, Robert Anderson of Scotland created the first electric carriage. The following year, a small electric car was built by the team of Professor Stratingh of Groningen, Holland and his assistant, Christopher Becker. More practical electric vehicles were brought onto the road by both American Thomas Davenport (1802-51) and Scotsman Robert Davidson (1804-1894) circa 1842. Both of these inventors introduced non- rechargeable electric cells in the electric car. The Parisian engineer Charles Jentaud fitted a carriage with an electric motor in 1881. William Edward Ayrton and John Perry, professors at the London's City and Guilds Institute, began road trials with an electrical tricycle in 1882; three years later a battery-driven electric cab serviced Brighton. Around 1900, internal combustion engines were only one of three competing-technologies for propelling cars. Steam engines were used, while electric vehicles were clean, quiet, and did not smell. In the United States, electric cabs more...

Useful as it might have been, an indication to drivers of how fast their automobiles were actually moving was not an option for pioneer motorists. The first production cars sported no such frivolous extras, but the race to develop suitable technology had begun. Extrapolating speed from the time taken to travel a given distance had been used for centuries, but it was a system for indicating an automobile's speed in real time—the speedometer proper—that was needed. The electric speedometer, in a form that would be recognized today, appeared between the late nineteenth and early twentieth centuries. Josip Belusic, a Croatian professor from the (then) Aystro- Hungarian region of Labin, was granted a patent for his electric "velocimeter" as early as 188-8. Other inventors were to produce various speedometers over the years that followed, and although most would achieve the required objective—to measure the rotational speed of the wheels or some more...

Definition:  Factorial: The number of sequences that can exist with a set of items, derived by multiplying the number of items by the next lowest number until 1 is reached. In mathematics, product of all whole numbers up to the number considered. The special case zero factorial is defined to have value 0!=1, consistent with the combinatorial interpretation of there being exactly one way to arrange zero objects. The notation n factorial (n!) was introduced by Christian Kramp in 1808. Permutation: An arrangement is called a Permutation. It is the rearrangement of objects or symbols into distinguishable sequences. When we set things in order, we say we have made an arrangement. When we change the order, we say we have changed the arrangement. So each of the arrangement that can be made by taking some or all of a number of things is known as Permutation.  Combination: A Combination is more...

Definition:  Permutation: An arrangement is called a Permutation. It is the rearrangement of objects or symbols into distinguishable sequences. When we set things in order, we say we have made an arrangement. When we change the order, we say we have changed the arrangement. So each of the arrangement that can be made by taking some or all of a number of things is known as Permutation.  Combination: A Combination is a selection of some or all of a number of different objects. It is an un-ordered collection of unique sizes.In a permutation the order of occurence of the objects or the arrangement is important but in combination the order of occurence of the objects is not important.   Formula: 

• Factorial=n! = 1*2*3*...*n.
• Permutation = nPr = n! / (n-r)! 
• Combination = nCr = nPr / r! =n!/(n-r)! r!

where,       more...