SSC CHSL GK Questions 2026

In 1643 the Italian scientist Torricelli filled a long glass tube with mercury and inverted it in a dish, and the column that stayed up showed that the air outside was pressing on the mercury; that apparatus is the mercury barometer, and the unit torr is named after him.

Babbage designed the difference engine and then the analytical engine, a mechanical machine with a store, a mill and punched card input, which carried every idea of a modern general purpose computer, and he is therefore called the father of the computer.

Working at the CERN laboratory in 1989, Berners-Lee proposed a system of linked documents and wrote the first web browser and server, giving the world HTML, HTTP and the address form known as the URL.

Chadwick showed in 1932 that the radiation given off when beryllium is struck by alpha particles consists of neutral particles of about the mass of a proton, and he named them neutrons; he received the Nobel Prize in Physics for it.

Fleming noticed in 1928 that a mould of the genus Penicillium had killed the bacteria growing around it on a culture plate, and the substance he named penicillin became the first antibiotic; Florey and Chain later turned it into a usable drug and shared the Nobel Prize with him.

The Swedish chemist Alfred Nobel patented dynamite in 1867, a safe way of handling nitroglycerine, and the fortune he made from explosives endowed the Nobel Prizes, first awarded in 1901.

Bell received the patent for the telephone in 1876 and made the first call over a wire, carrying the human voice itself rather than a code.

Paul Hermann Muller is remembered for showing that DDT kills insects, work for which he received a Nobel Prize in Physiology or Medicine; vitamin D is associated with Edward Mellanby, who linked its absence to rickets, and with Adolf Windaus, who worked out its chemistry.

In 1796 Jenner showed that material from a cowpox sore protected a boy against smallpox, the first deliberate vaccination, and the word vaccine itself comes from vacca, the Latin for cow.

Roentgen, a German physicist, noticed in 1895 that a screen in his darkened laboratory glowed while a covered discharge tube was running, and he named the unknown radiation X-rays.

Kudankulam in the Tirunelveli district of Tamil Nadu uses pressurised water reactors of the Russian VVER type, supplied under an agreement signed with the Soviet Union in 1988 and carried forward by Russia.

The Jaduguda mine lies in the Singhbhum belt of Jharkhand and has been worked by the Uranium Corporation of India Limited, a public sector company set up in 1967, since the late nineteen sixties; it was the first uranium mine in the country.

On 11 May 1998 India tested three nuclear devices at Pokhran under Operation Shakti, followed by two more on 13 May, and the day was declared National Technology Day to mark that achievement along with the test flight of the Trishul missile and the first flight of the Hansa aircraft…

The test was carried out in the desert at Pokhran in Rajasthan on 18 May 1974 and was described by India as a peaceful nuclear explosion; Raja Ramanna led the team.

The second stage uses the plutonium 239 recovered from the spent fuel of the first stage as the fuel of a fast breeder reactor, with a blanket of thorium around the core that is converted into uranium 233; a breeder produces more fissile material than it burns, which is how…

Apsara went critical at Trombay near Mumbai on 4 August 1956 and was the first nuclear research reactor not only in India but in the whole of Asia; the CIRUS reactor of 1960 and the Dhruva reactor of 1985 were built at the same site, which is today the Bhabha…

Bhabha founded the Tata Institute of Fundamental Research in 1945, became the first chairman of the Atomic Energy Commission in 1948, drew up the three stage plan built around India's thorium, and led the establishment at Trombay that was renamed the Bhabha Atomic Research Centre after his death in 1966.

In a boiling water reactor, the design used at Tarapur, ordinary water is allowed to boil inside the reactor vessel itself, so the coolant leaving the core is a mixture of water and steam; the steam is separated at the top and driven straight to the turbine, without the separate…

The CANDU design, from which India's pressurised heavy water reactors descend, burns natural uranium, and natural uranium contains only about seven parts in a thousand of the fissile isotope uranium 235.

The Tarapur Atomic Power Station in Maharashtra was commissioned in 1969 with American assistance and was the first nuclear power station in India as well as in Asia; its first two units are boiling water reactors, a design used nowhere else in the country.