Defence GK Questions 2026

Kessler, then working with the American space agency, published the argument that once the population of objects in low Earth orbit crosses a certain density, collisions between them will generate fragments faster than the atmosphere can drag the old debris down.

Global Positioning System satellites orbit at about 20,200 kilometres, which lies in the medium Earth orbit band stretching from 2,000 kilometres up to the geostationary height of 35,786 kilometres.

The British science fiction writer and engineer set out in 1945 how three satellites placed in a circular equatorial orbit at about 36,000 kilometres could relay radio signals to almost the whole inhabited world.

Such an orbit is near-polar, typically 600 to 900 kilometres high with an inclination of about 98 degrees, which makes it retrograde.

A geostationary satellite must match the rotation of the Earth with respect to the distant stars, and that rotation takes one sidereal day.

Only at this height does a satellite in a circular equatorial orbit take exactly one sidereal day to complete a revolution, which is the condition for appearing stationary above one point on the Earth.

The institute, which lies at Izatnagar near Bareilly, is the country's premier centre for veterinary research and teaching, covering animal diseases, vaccines and livestock production, and it has a second campus at Mukteswar in the Nainital district.

The institute is the country's reference laboratory for viral diseases, it tests and confirms outbreaks and it also works on vaccines; the National AIDS Research Institute is in the same city.

The institute works on food processing, preservation, packaging and nutrition, and it shares the city with the Defence Food Research Laboratory, so Mysuru is best remembered as the food research city.

The institute is a laboratory of the Council of Scientific and Industrial Research and studies the physics, chemistry, biology and geology of the seas around India, with regional centres at Kochi, Visakhapatnam and Mumbai.

The institute works on dryland farming, sand dune stabilisation, agroforestry and the management of grazing land in the arid west of the country, and it comes under the Indian Council of Agricultural Research.

The institute is the country's main centre for research and training in dairy science, covering animal breeding, milk production and dairy technology, and it works under the Indian Council of Agricultural Research; Karnal also holds the Central Soil Salinity Research Institute.

The institute began in 1905 at Pusa in Bihar, and after the Bihar earthquake of 1934 damaged its buildings it was shifted to Delhi, where the campus is still called Pusa; it is the country's leading agricultural research and teaching institute and was central to the Green Revolution.

The centre was set up in 1971 and is the country's main laboratory for the second stage of the nuclear programme, in which plutonium from spent fuel is used in fast breeder reactors; the Fast Breeder Test Reactor and the prototype fast breeder project are both at Kalpakkam.

The spaceport lies on an island on the Bay of Bengal coast, chosen because launches to the east pass over the sea and because its nearness to the equator helps eastward launches; it is named after Satish Dhawan, a former chairman of ISRO.

The centre began in 1954 as the Atomic Energy Establishment, Trombay and was renamed the Bhabha Atomic Research Centre in memory of Homi Jehangir Bhabha, the architect of India's atomic programme; the research reactors Apsara, Cirus and Dhruva are all on this campus.

Founded in 1883, it is India's oldest conservation body, it works from Mumbai, and besides the popular magazine Hornbill it publishes a scientific journal and runs long-running bird and wildlife surveys; Salim Ali, the country's best known ornithologist, was associated with it for decades.

It was signed on 2 February 1971 in the Iranian city of Ramsar, which is why the treaty is always called the Ramsar Convention and why 2 February is kept as World Wetlands Day.

The Convention on Biological Diversity was opened for signature at the Rio Earth Summit in 1992 and came into force in 1993; its secretariat works from Montreal, and its two protocols are the Cartagena Protocol on biosafety and the Nagoya Protocol on access to genetic resources and the fair sharing…

The IPCC was created in 1988 so that governments would have an authoritative, regularly updated assessment of climate science; its secretariat is at Geneva, and it shared the 2007 Nobel Peace Prize with Al Gore.