Science & Technology Mixed Quiz: Set 30

The correct answer is B, Medium Earth Orbit. 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. At that altitude each satellite takes roughly twelve hours to go round, and a constellation of them keeps several satellites visible from any point on the Earth, which is what a receiver needs to fix its position.

Option A, Low Earth Orbit, is used by space stations and remote sensing satellites; a navigation satellite there would sweep past too quickly to be useful. Option C, Geostationary Orbit, is used by communication and weather satellites, and India's NavIC does use geostationary and inclined geosynchronous orbits because it is a regional system, but the American GPS is a medium Earth orbit constellation. Option D, Sun-synchronous Orbit, is a specialised low Earth orbit for imaging.

The correct answer is C, Both 1 and 2. LiFi (Light Fidelity) sends data wirelessly by switching LED light on and off far too fast for the eye to notice, and it can be many times faster than WiFi.

The idea was popularised by Professor Harald Haas of the University of Edinburgh in 2011. A LiFi bulb flickers at very high frequency, and a photodetector reads these changes as binary data. Because visible light has a far wider spectrum than the radio waves used by WiFi, laboratory tests have reached speeds many times higher than WiFi. Light cannot pass through walls, which limits range but makes the signal harder to intercept and free of radio interference, useful in hospitals and aircraft.

A is wrong because statement 2 is also correct.

B is wrong because statement 1, the use of light, is the very basis of LiFi.

D is wrong because both statements describe LiFi correctly.

Exam tip: WiFi uses radio waves; LiFi uses visible light from LEDs and cannot pass through walls.

The correct answer is A, Norway. Himadri was opened in 2008 at Ny-Alesund on the Svalbard archipelago, which belongs to Norway. Svalbard is governed by a treaty that allows the nationals of its parties to carry on research and economic activity there, which is what makes an international research village at Ny-Alesund possible.

Option B, Iceland, has no Indian research station, though it is an Arctic Council member. Option C, Canada, and option D, Russia, both have large Arctic territories and their own extensive Arctic research, but India's station is not on their soil. Remember the associated facts: IndARC, India's moored underwater observatory, was deployed in the Kongsfjorden fjord off Svalbard in 2014, India has been an Observer in the Arctic Council since 2013, and India's Arctic Policy was released in 2022.

The correct answer is C, Dakshin Gangotri. It was built during the Indian expedition of 1983 to 1984 in Queen Maud Land and was India's first permanent base on the continent. Because it stood on a floating ice shelf, the movement of the ice and the steady accumulation of snow buried it, and it was given up as a working station in 1990, after which it has served only as a supply base and transit camp.

Option A, Maitri, is the second station, commissioned in 1989, and is the answer most candidates give because it is the station they have heard of. Option B, Bharati, is the third station, commissioned in 2012. Option D, Himadri, is not in Antarctica at all; it is India's Arctic station in Svalbard, Norway, and it is placed here precisely to catch the confusion between the two poles. The order to remember is Dakshin Gangotri, then Maitri, then Bharati.

The correct answer is A, Donald J. Kessler in 1978. 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. Each collision then feeds the next one, and the cascade can continue even if no further launches take place.

Option B keeps the right person but the wrong year, which is the commonest error in this question, so the pairing of Kessler with 1978 should be memorised together. Option C, Hermann Oberth, was one of the founding theorists of rocketry and had nothing to do with debris modelling, and 1957 is the year of Sputnik 1. Option D, Wernher von Braun, led the development of the Saturn V rocket, and 1969 is the year of the first Moon landing. Both wrong options are built out of famous but unrelated space dates.

The correct answer is C, 35,786 km. 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 figure is commonly rounded to about 36,000 kilometres, and both forms are accepted in answers.

Option A, 3,578 km, is the same digits with a misplaced decimal and is included to catch hasty reading. Option B, 20,200 km, is the altitude of the Global Positioning System satellites, which lie in medium Earth orbit and have a period of about twelve hours, not one day. Option D is far too high and is closer to the scale used for Lagrange point missions; India's Aditya-L1, for instance, sits about 1.5 million kilometres away at the Sun-Earth point L1. Remember the trio: low Earth orbit up to 2,000 km, medium Earth orbit beyond that, and geostationary at 35,786 km.

The correct answer is B, Goa. The National Centre for Polar and Ocean Research is at Vasco-da-Gama in Goa and works under the Ministry of Earth Sciences. It was established in 1998 as the National Centre for Antarctic and Ocean Research and was renamed in 2018, when its mandate had grown from Antarctica to the Arctic, the Southern Ocean and the Himalayan cryosphere.

Option C, Tamil Nadu, is where the National Institute of Ocean Technology is located, at Chennai; that institute builds Matsya-6000 and other ocean hardware, and candidates often mix the two bodies up. Option A, Kerala, and option D, Maharashtra, host other scientific institutions but not this one. A third name worth remembering in the same ministry is the Indian National Centre for Ocean Information Services at Hyderabad, which runs the tsunami early warning centre.

The correct answer is B, Vikram-S. Vikram-S was built by Skyroot Aerospace of Hyderabad and flew a sub-orbital mission from Sriharikota in November 2022 under the name Mission Prarambh, which means beginning. It was the first rocket designed and built by an Indian private company to fly, and it is named after Vikram Sarabhai. Option A is wrong because Agnibaan, of Agnikul Cosmos, flew later, in 2024, although its SOrTeD flight set its own record for a single-piece three-dimensionally printed engine. Option C is wrong because the Small Satellite Launch Vehicle is ISRO's own rocket and its first developmental flight was in 2022 from Sriharikota. Option D is wrong because Rohini sounding rockets are ISRO's own series, flown since the early years of the programme.

The correct answer is B, Microsat-R. In Mission Shakti an interceptor developed by the Defence Research and Development Organisation was launched from Dr. A. P. J. Abdul Kalam Island off the Odisha coast and destroyed India's own Microsat-R satellite in low Earth orbit at a height of about 283 kilometres. The low altitude was chosen on purpose so that the fragments would lose energy and re-enter the atmosphere quickly rather than linger in orbit.

Option A, Cartosat-2, is a working Indian remote sensing satellite and was never a target. Option C, RISAT-2B, is a radar imaging satellite launched a few months after the test. Option D, Fengyun-1C, is the Chinese weather satellite destroyed in China's own anti-satellite test of January 2007, which produced the largest cloud of trackable debris in history and is the usual distractor here. With Mission Shakti India became the fourth country after the United States, Russia and China to demonstrate this capability.

The correct answer is B, twenty-one million. The bitcoin protocol fixes the total supply at twenty-one million coins. New coins enter circulation only as the reward paid to whoever adds a block, and that reward is halved every two hundred and ten thousand blocks, which works out to roughly every four years, so issuance falls geometrically towards zero. This built-in scarcity is why bitcoin is often described as deflationary by design. Option A is wrong because one crore, that is ten million, is below the protocol limit. Option C is wrong because one hundred million is the number of the smallest units, called satoshis, in a single bitcoin, not the number of bitcoins. Option D is wrong because an unlimited supply is the feature of ordinary fiat currency, which a central bank can issue at will, and the fixed cap is precisely the contrast bitcoin was designed to draw.

The correct answer is A, Dr. Syed Zahoor Qasim. A marine biologist, he led the first Indian scientific expedition to Antarctica in 1981, a voyage that established India's presence on the continent and paved the way for accession to the Antarctic Treaty and for Consultative Party status in 1983. Indian expeditions have gone to Antarctica every year since.

Option B, Dr. Vikram Sarabhai, was the founder of the Indian space programme and died in 1971, long before this expedition. Option C, Dr. Satish Dhawan, headed the space programme in the 1970s and 1980s and is associated with the launch centre named after him, not with polar science. Option D, Dr. Harsh Gupta, is a distinguished Indian earth scientist who has worked on seismology and oceanography, but he did not lead the first expedition. Pair Qasim with 1981 and the ship that carried the team south.

The correct answer is A, the Ministry of Health and Family Welfare. The Authority was created by the Food Safety and Standards Act, 2006, was established in 2008 and works under that Ministry with its headquarters at New Delhi, because food safety is treated as a public health matter. Option B is wrong because the Ministry of Agriculture and Farmers’ Welfare runs Agmark grading through the Directorate of Marketing and Inspection, which concerns the grade of produce, not its safety. Option C is wrong because the Ministry of Consumer Affairs, Food and Public Distribution handles the Bureau of Indian Standards and the public distribution system. Option D is wrong because the Ministry of Food Processing Industries promotes the processing industry through schemes and parks, and the regulator remains the Authority under the Health Ministry.

The correct answer is B, tracking and analysis of objects in space, including debris. NETRA stands for Network for Space Objects Tracking and Analysis. It is ISRO's programme to build radar, optical telescope and control centre capability for space situational awareness, so that India can detect, track and catalogue objects in orbit and warn its own satellites about possible close approaches instead of depending entirely on data from abroad. It works alongside IS4OM, the ISRO System for Safe and Sustainable Operations Management, set up at Bengaluru.

Option A is wrong because human spaceflight preparation comes under the Gaganyaan programme and its astronaut training facility. Option C is wrong because crop insurance support uses remote sensing data under separate schemes of the agriculture ministry. Option D is wrong because launching navigation satellites is a mission activity; NETRA is a surveillance and safety network, not a launch programme.

The correct answer is C, 2015. AstroSat was launched on 28 September 2015 by PSLV-C30 from Sriharikota into a near equatorial low Earth orbit. It carries five payloads, including the Ultraviolet Imaging Telescope, the Soft X-ray Telescope, the Large Area X-ray Proportional Counter, the Cadmium Zinc Telluride Imager and a scanning sky monitor, so that the same source can be studied in the ultraviolet and in both soft and hard X-rays at once, which few observatories can do. A is the year of Chandrayaan-1, the first lunar mission, and B of the Mars Orbiter Mission, both of which candidates confuse with AstroSat because all three are firsts. D belongs to Chandrayaan-2. Its scanning sky monitor also looks for sources that brighten suddenly, such as X-ray binaries in outburst.

The correct answer is B, 1959. The Antarctic Treaty was signed on 1 December 1959 by twelve nations that had been active in the continent during the International Geophysical Year, and it came into force in 1961. It devotes Antarctica to peaceful purposes, forbids military activity, nuclear explosions and the dumping of radioactive waste, guarantees freedom of scientific research and sets aside existing territorial claims for the life of the treaty.

Option A, 1949, predates the treaty negotiations. Option C, 1982, is the year the United Nations Convention on the Law of the Sea was adopted, which governs the oceans and the deep seabed rather than Antarctica, and it is the main distractor. Option D, 1991, is the year of the Madrid Protocol on Environmental Protection, which declares Antarctica a natural reserve devoted to peace and science and bans mineral resource activity other than research. India acceded to the treaty in 1983 and passed the Indian Antarctic Act in 2022.

The correct answer is B, Snow Crash by Neal Stephenson. The novel, published in 1992, uses the word metaverse for a shared virtual city that people enter through goggles and move about in as avatars, and the term was taken up decades later for persistent three-dimensional online worlds. Option A is wrong because Neuromancer, published in 1984, gave the world the related term cyberspace, not metaverse. Option C is wrong because Ready Player One, a later novel, describes such a world but did not name it; it borrows from the idea rather than coining it. Option D is wrong because the Sword of Damocles is not a book at all but the nickname of the head-mounted display Ivan Sutherland built in 1968, the first of its kind.

The correct answer is A, Iridium 33 and Kosmos 2251. In February 2009 the working American communication satellite Iridium 33 and the defunct Russian military communication satellite Kosmos 2251 struck each other over Siberia at a relative speed of several kilometres per second. Both were destroyed and the event created thousands of trackable fragments, proving that an accidental collision between whole satellites was no longer a theoretical worry.

Option B names two European Earth observation satellites that never collided. Option C pairs the targets of the Chinese and Indian anti-satellite tests, which were deliberate destructions of a country's own satellite, not an accident, and they happened in different years. Option D names the first Soviet and first American satellites of 1957 and 1958, which were in orbit at very different times and were tiny by comparison. Remember 2007 for Fengyun-1C, 2009 for Iridium-Kosmos and 2019 for Mission Shakti.

The correct answer is A, Ministry of Earth Sciences. The Cabinet approved the Deep Ocean Mission in June 2021 with this ministry as the implementing agency and an estimated cost of about 4,077 crore rupees spread over five years in phases. The ministry also controls the three institutes that carry out the work: the polar and ocean research centre in Goa, the ocean technology institute at Chennai and the ocean information services centre at Hyderabad.

Option B, the Ministry of Science and Technology, runs the departments of science and technology and of biotechnology, which have their own programmes but not this mission. Option C, the Ministry of Ports, Shipping and Waterways, deals with shipping and port infrastructure, which is part of the blue economy but not of this mission. Option D, the environment ministry, handles forests, wildlife and climate negotiations. The mission's six components are worth listing separately, since matching questions are set on them.

The correct answer is B, a few hundred kilometres above the geostationary belt. A communication satellite nearing the end of its life keeps a small reserve of fuel to raise itself out of the crowded geostationary ring into a higher orbit where it cannot drift back into a working slot or collide with an active satellite. Bringing such a satellite all the way down for re-entry would need far more fuel than raising it, which is why disposal upward is the accepted practice at that altitude.

Option A describes the opposite approach, used for low Earth orbit satellites, which are lowered so that atmospheric drag pulls them down for re-entry. Option C is wrong because the sun-synchronous band is a busy working region for imaging satellites and nothing is parked there deliberately. Option D is wrong because the Lagrange points are used for science missions such as space observatories, not for dumping retired hardware.

The correct answer is B, three people to 6,000 metres. Matsya-6000 takes its name from the design depth of six thousand metres and is built to carry a crew of three inside a titanium personnel sphere. It is planned for about twelve hours of normal operation on a dive, with an endurance of roughly ninety-six hours in an emergency so that the crew can survive until rescue.

Option A understates both figures. Option C changes the crew to four, which the sphere is not sized for. Option D takes the depth to eleven thousand metres, which is close to the deepest point of the ocean in the Mariana Trench; only a handful of specialised vehicles in the world are built for that depth and Matsya-6000 is not one of them. The project under which the submersible is being built is called Samudrayaan, and it is the crewed component of the Deep Ocean Mission.