WB JEE Medical

Harnessing the power of the atom has been a major goal of both science and science fiction, capturing the public imagination with the promise of cheap, clean energy. The initial idea was developed until December 20, 1951, when a switch was flicked and the Experimental Breeder Reactor 1 (EBR1) was switched on, becoming the first nuclear reactor to generate electrical energy, and therefore become the first nuclear power plant. The heat generated from the reaction was used to turn water into steam, turning turbines to generate electricity. On its first successful run the reactor produced enough power to run just four lightbulbs. The next day it produced enough to power the entire research facility, and today nuclear power stations, many of them based on this original design, provide some 16 percent of the world's electricity. Walter Zinn (1906-2000), the chief scientist behind the work, started his career in nuclear engineering more...

The idea of curing rubber goes back to prehistoric times. The Aztecs, for example, processed rubber by mixing latex with vine juice. However, vulcanization, as we now think of it, was invented by Charles Goodyear (1800-1860) in 1839 (according to his own account). Although Goodyear patented his invention in 1844, he died with huge debts in 1860. Named after Vulcan, the Roman god of fire, vulcanization is a process of curing rubber using high temperatures and the addition of sulfur. In its natural state, rubber is sticky, deforms when warm, and is brittle when cold. But by linking together the polymer molecules in rubber with bridges of sulfur atoms, it becomes much harder, less sticky, more resistant, and much more durable. As a result, vulcanized rubber has a whole range of useful applications, not least in sealing gaps between moving parts, thereby playing a crucial part in the development of more...

"Every occasion will catch the senses of the vain man and with that... saddle you may ride him." Sir Philip Sidney, politician It is unclear when humans first began to domesticate and ride horses—evidence from cave paintings in France suggests that horses might have been bridled as long ago as 15,000 B.C.E. But while early riders had the use of bits, bridles, and harnesses to control their mounts, they sat uncomfortably on little more than folded blankets or cloth, or rode bareback. Asian horsemen created a felt and wood saddle around 300 B.C.E., but it was not until around 100 C.E. that riders gained a saddle that offered genuine comfort. The first padded, framed saddles were-developed in Han Chin sometime between 25 and 220 C.E. They consisted of a wooden frame covered in a stiff material such as leather, padded with cloth and shaped for comfort. To ensure a good more...

"Camouflage is a game we like to play, but our secrets are revealed by... what we want to conceal" Russell Lynes, author and editor Although hunters and some elite military units had long made use of camouflage, most armies, until the end of the nineteenth century, wore brightly colored, distinctive uniforms to distinguish friend from foe on the battlefield among gunpowder smoke and to attract new recruits. The British Army was the first to eschew bright uniforms in favor of those that would help to conceal their men. Heavy casualties during the Indian Revolt of 1857 forced them to dye their scarlet tunics a dull brown color, or "khaki." White summer uniforms were dyed using the simple and quintessentially British expedient of dipping them in tea. Khaki uniforms became standard in India in the 1880s and in the rest of the army during the Second Boer War in 1902. At more...

India has repeatedly said it wants peace with its neighbourers and utilise its nuclear option for peaceful purposes. But it must also be prepared to defend itself in case some enemy attacks it. India is no exception. China and Pakistan are India's neighbours. They have utilized every resource to prepare themselves in case of a war. China is now not only major nuclear power in Asia, it has also helped Pakistan to develop nuclear weapons. Pakistan has also been enjoying economic and military aid from the U.S.  India, being a big country, too has to make her presence felt in the region. For this to be accomplished, she has been involved in nuclear research since long. India faced a crushing and humiliating defeat in its war with China in 1962, and this has forced her to be prepared for any threat in future. Manufacturing nuclear weapons is very important for more...

Introduction. 15th August is the biggest National Festival of India. On this day in 1947, India got freedom from the British rule. For many years foreigners ruled over India. The morning of 15th August 1947, brought a new hope in the hearts of all Indian men, women and children. From that day we celebrate this auspicious day with great pomp and show.  Struggle against the Britishers. Freedom of India was the result of ninny sacrifices of our national leaders.  Mahatma Gandhi, Jawahar Lal Nehru, Sardar Patel, Subhash Chander Bose, Maulana Abul Kalam Azad ind many others struggled against the English rule and went to jail many (lines. All these leaders demanded 'Total Independence' and nothing less. Mahatma Gandhi raised his voice against the exploitation only by his non- Violent ways. Jawahar Lal Nehru and Subhash Chander Bose went abroad many times to raise their voice and win the confidence of more...

Now a day there is a large scale of migration of people from villages to big cities. Though the villages have greenery, peace and fresh air yet there are little chances for searching good jobs. Moreover there are different charms and attractions of big cities, which attract these people. In cities roads are property metalled and, well lighted. There is large number of civic amenities available in the cities. Cities have proper sanitation system Treated pure water is available. There are different types of public transportation facilities. There are big parks. Streets and roads have proper lighting system. There are well furnished houses in the cities. All these facilities are not available in villages Big cities have a complete education system. There are big universities. Government and  posh private public schools. There are big libraries. By living in big cities we can know about the all out development of country more...

Mrs. Indira Gandhi was the beloved leader of the people of India After her downfall in 1977, the people had again placed the country in her hands in 1980. She was born on Nov. 19,1917. She was brought up in a family full of political activities and love of country. So the family atmosphere had a great influence on her mind. She got her education at Allahabad, Oxford and Shanti Niketan. In 1942 she was married to Mr. Feroz Gandhi, a Parasi youth. He died in 1960, she had two sons-Rajiv and Sanjay. Indira Gandhi was the worthy daughter of a worthy father. She was a born politician. After the death of her mother she had a very difficult time. In her early life she jumped into politics. She had been the member of Indian National Congress. In 1950 she was elected  President of N. Congress. It was only after more...

As long as railways have existed, there have been model versions. Initially, the trains were Just pull-along, but they gradually developed to use miniature steam or clockwork engines. By 1891, the German company Marklin was selling a wind-up locomotive together with an expandable track system. Then, in 1896, Carlisle and Finch produced the first electric toy train powered by batteries. American entrepreneur Joshua Lionel Cowen (1877-1965) had a long-term interest in trains. At the age of seven he had whittled a locomotive out of wood, which exploded when he tried to fit it with a steam engine. Years later when he was researching products for his manufacturing company in New York to sell, he spotted a push train in a shop window and had the idea for a toy train that could run without supervision on a track. He initially envisaged it as an eye-catching window display for a toy more...

Coal is a very useful and important mineral. It is black and hard. It is lifted from coal mines. Coal is nothing but the wood in forests that went underground thousands of years ago. There are different kinds of coal such as peat, lignite, bituminous and anthracite. Anthracite is the best variety of coal. There are many coal mines in India. Of these Raniganj, Jharia, Chirimiri and Chandrapur are famous for their coal mines. Coal has different uses. It is chiefly used as fuel. It is the main source of energy resources. Coal is used to produce thermal electric power and steam power. Coal has also other uses. From it we get gas, dyes, tar, nylon, naphthalene and many other useful byproducts. Thus, coal has occupied an important place in our day to day life. However, its quantity is limited on the earth and we have used up a large more...