Science & Technology Mixed Quiz: Set 18

The correct answer is C, Diu. Diu, on the coast of Gujarat, was declared the first union territory in India to run entirely on solar power. It built a solar park on rocky waste land near the coast and added rooftop plants on government buildings, and together these meet its full daytime demand, so the territory no longer draws power from outside during the day. Option A is wrong because the Andaman and Nicobar Islands have long depended on diesel generation and are now adding solar and diesel hybrid systems island by island. Option B is wrong because Chandigarh is promoted as a model solar city with compulsory rooftop installation on larger buildings, but it still draws most of its power from the northern grid. Option D is wrong because Puducherry has rooftop and solar pump programmes but was never declared fully solar powered.

The correct answer is C, August 2021. The Prime Minister announced the National Hydrogen Mission in his Independence Day speech from the Red Fort on 15 August 2021, with the aim of making India a hub for producing and exporting green hydrogen. Green hydrogen is made by splitting water through electrolysis using electricity from solar, wind or other renewable sources, so it releases no carbon dioxide, unlike the grey hydrogen made from natural gas. The Union Cabinet later approved the National Green Hydrogen Mission in January 2023 with an outlay of Rs 19,744 crore. Option A is wrong because May 2021 saw no such announcement. Option B is wrong because November 2021 is when the Prime Minister gave the Panchamrit climate pledges at the Glasgow COP26 summit. Option D is wrong because January 2021 belongs to the vaccination drive against Covid-19, not to hydrogen. Exam tip: announced 15 August 2021; the mission was approved by the Cabinet in January 2023.

The correct answer is B, one billionth of a metre. The prefix nano stands for ten raised to the power minus nine, so one nanometre is one billionth of a metre, which is also ten angstrom, and nanotechnology is defined as work in the band of one to one hundred nanometres. Option A is wrong because one millionth of a metre is a micrometre or micron, the unit used for bacteria and for the thickness of a hair in older textbooks, and it is a thousand times larger than a nanometre. Option C is wrong because one thousandth of a metre is a millimetre, a length visible to the eye on any ruler. Option D is wrong because one trillionth of a metre is a picometre, a unit used for bond lengths inside a molecule and a thousand times smaller than a nanometre; the diameter of an atom is of the order of a hundred picometres.

The correct answer is B, superposition. A classical bit must be either zero or one, but a qubit can occupy a combination of both states until it is measured, and this is what allows a register of n qubits to represent two raised to the power n states together. Option A is wrong because entanglement is the separate property by which two particles share a single quantum state, so that measuring one instantly fixes the outcome for the other however far apart they are. Option C is wrong because decoherence is the opposite of a useful property: it is the loss of quantum behaviour when a qubit interacts with its surroundings, and it is the main engineering obstacle. Option D is wrong because tunnelling, the passage of a particle through a barrier it classically could not cross, is a different quantum effect altogether.

The correct answer is C, Electrolysis of water using renewable electricity. Hydrogen is called green only when the electricity that splits the water comes from a renewable source such as solar or wind, so that no carbon dioxide is released in making it. Option A is wrong because steam reforming of natural gas is the route for grey hydrogen, which is the cheapest and the most widely used route today and releases carbon dioxide to the air; the same route with carbon capture gives blue hydrogen. Option B is wrong because gasification of coal or lignite gives brown or black hydrogen, the route with the highest emissions of all. Option D is wrong because fractional distillation separates petroleum into fractions such as petrol, kerosene and diesel and is not a method of producing hydrogen at all.

The correct answer is A, IIT BHU. PARAM Shivay was commissioned in 2019 at the Indian Institute of Technology (BHU), Varanasi, and it was the first supercomputer assembled within India under the National Supercomputing Mission. The mission was launched in 2015 and is steered jointly by the Ministry of Electronics and Information Technology and the Department of Science and Technology, with C-DAC Pune and the Indian Institute of Science, Bengaluru, as the implementing agencies. The point of assembling the machine in India was to build local skill in high performance computing hardware.

Option B, IIT Kharagpur, received PARAM Shakti, a later system of the same mission, so the institute is right for a different machine. Option C, IISc Bengaluru, is an implementing agency of the mission and hosts PARAM Pravega, commissioned in 2022. Option D, IISER Pune, hosts PARAM Brahma. All four institutions have mission systems, which is exactly the confusion the question sets up; only PARAM Shivay at IIT (BHU) was the first.

The correct answer is B, Norio Taniguchi. The Japanese engineer Norio Taniguchi used the word nanotechnology in 1974 to describe machining to tolerances of a nanometre, and that is the coinage examiners expect. Option A is wrong, and it is the usual trap: Richard Feynman gave the famous lecture There's Plenty of Room at the Bottom in 1959, which set out the idea of building with individual atoms, but he never used the word, so he is credited with the concept and not with the term. Option C is wrong because K. Eric Drexler popularised the word through his book Engines of Creation in 1986 and through the phrase molecular nanotechnology, which is popularisation rather than coinage. Option D is wrong because Sumio Iijima reported carbon nanotubes in 1991, a landmark material but much later than the naming of the field.

The correct answer is C, methane. Biogas is produced by the anaerobic digestion of organic matter, and methane is its largest component, roughly half to three quarters of the gas by volume; this is what makes biogas combustible. Option A is wrong because carbon dioxide is the second largest component, usually a quarter to a half, and it does not burn; it is scrubbed out when raw biogas is upgraded to compressed bio-gas. Option B is wrong because hydrogen sulphide is present only in traces, and it is removed because it is corrosive and foul smelling. Option D is wrong because carbon monoxide is a product of incomplete combustion of fuels and is not a normal constituent of biogas at all. Upgraded compressed bio-gas is over ninety per cent methane.

The correct answer is B, Blue hydrogen. Blue hydrogen is made by the same fossil route as grey hydrogen, usually steam reforming of natural gas, but the carbon dioxide produced is captured and stored underground instead of being released, so its emissions are much lower though not zero. Option A is wrong because grey hydrogen is exactly the same process without capture, which is why reading the words carbon capture in the question decides the answer. Option C is wrong because pink hydrogen, also called purple hydrogen, is made by electrolysis using electricity from a nuclear plant, which is a non-fossil route. Option D is wrong because turquoise hydrogen is made by pyrolysis of methane, where the carbon leaves the process as a solid that can be stored or sold rather than as a gas that has to be captured.

The correct answer is C, 2014. The World Health Organization certified the South East Asia Region, India included, as free of wild poliovirus in March 2014, three years after the last case in the country, because certification requires three consecutive years without a case. Option A is wrong but names the other date worth knowing, since India recorded its last case of wild poliovirus in January 2011, in West Bengal. Option B is wrong; by 2012 India had been removed from the list of polio endemic countries, but formal certification of the region had not yet come. Option D is wrong because 2016 belongs to a different achievement, the declaration that India was free of yaws. Keep the two polio dates as a pair, 2011 for the last case and 2014 for certification, and remember that the Pulse Polio Programme of 1995 made both possible.

The correct answer is A, Richard Feynman. The American physicist Richard Feynman delivered the talk There's Plenty of Room at the Bottom to the American Physical Society at Caltech in December 1959, in which he argued that there is no law of physics forbidding the manipulation of individual atoms, and the lecture is treated as the conceptual birth of nanotechnology. Option B is wrong because Albert Einstein, who died in 1955, worked on relativity, the photoelectric effect and Brownian motion, and had no part in this lecture. Option C is wrong because Gerd Binnig built the Scanning Tunnelling Microscope at IBM Zurich in 1981 with Heinrich Rohrer, giving the field its eyes rather than its founding idea. Option D is wrong because Harold Kroto shared the 1996 Nobel Prize in Chemistry for the discovery of fullerenes in 1985.

The correct answer is A, collector current to emitter current. In a bipolar junction transistor the emitter injects carriers, the thin lightly doped base lets most of them through, and the collector gathers them, so the emitter current divides into a large collector current and a small base current; alpha is defined as the collector current divided by the emitter current and is therefore always a little less than one, typically between 0.95 and 0.99. Option B is wrong because it inverts the ratio and would give a value greater than one. Option C is wrong because the base to collector ratio is a small fraction with no standard name. Option D is wrong because the collector current divided by the base current is beta, the current gain, which runs into the tens or hundreds. Keep alpha below one and beta well above one.

The correct answer is B, 2 kg of carbon dioxide equivalent per kg of hydrogen. The Ministry of New and Renewable Energy notified the Green Hydrogen Standard for India in August 2023, fixing the limit at two kilograms of carbon dioxide equivalent for each kilogram of hydrogen, averaged over twelve months, and covering the whole chain from water treatment through electrolysis, purification, drying and compression up to the plant gate. Both electrolysis and biomass routes may qualify. Option A is wrong because one kilogram is stricter than the notified Indian limit. Option C is wrong because five kilograms is close to what an efficient grey hydrogen plant emits, which is precisely what the standard is meant to exclude. Option D is wrong because ten kilograms is in the range of coal-based hydrogen and far above any green threshold.

The correct answer is B, 2019. The first Vande Bharat Express was flagged off on 15 February 2019, after the train set had been built at the Integral Coach Factory under the name Train 18 and tested on Indian track. Option A, 2016, is the year in which Gatimaan Express began running at 160 kilometres an hour and became India's first semi-high-speed train, and a candidate who mixes the two milestones will pick it. Option C, 2021, saw further trials and orders but no first service. Option D, 2023, is the year in which the number of Vande Bharat services grew quickly across the country, which is why many candidates associate the train with that year; the expansion, however, came four years after the first run. Pairing 2016 with Gatimaan and 2019 with Vande Bharat keeps the two apart.

The correct answer is A, 12. Buckminsterfullerene, discovered in 1985, has sixty carbon atoms arranged in a closed cage of twenty hexagons and twelve pentagons, exactly the pattern of a stitched football, and the twelve pentagons are what allow a flat hexagonal sheet to curve into a closed ball. Option B is wrong because twenty is the number of hexagonal faces, which the question itself supplies, and swapping the two counts is the standard trap in this item. Option C is wrong because thirty two is the total number of faces of the molecule, twenty plus twelve, not the number of pentagons alone. Option D is wrong because sixty is the number of carbon atoms, that is the vertices of the cage, and the molecule was named after the architect Buckminster Fuller, whose geodesic domes it resembles.

The correct answer is C, GSLV-D5 in January 2014. That flight carried the GSAT-14 communication satellite and was the first success of the indigenous cryogenic upper stage, which put India among the small group of countries able to build such an engine. Cryogenic technology is hard because liquid hydrogen must be held near minus 253 degrees Celsius and pumped into a running engine.

Option A, GSLV-D1 of April 2001, was the vehicle's first flight and used a Russian-supplied cryogenic stage, not an Indian one. Option B, GSLV-D3 of 2010, was the first attempt to fly the Indian stage and it failed, so the flight is remembered as the attempt rather than the success. Option D, the first orbital flight of LVM3 in June 2017, used the larger C25 cryogenic stage and came three years after the technology had already been proved on GSLV-D5.

The correct answer is C, Rupees 19,744 crore. The Union Cabinet approved the National Green Hydrogen Mission on 4 January 2023 with this outlay, to be spent up to the financial year 2029-30 across incentives, hubs, pilot projects, research and skilling. Option A is wrong because eight thousand crore rupees matches no component of the mission; the figure of eight lakh crore rupees that appears in mission documents is the total investment the mission hopes to attract, not government spending. Option B is wrong because seventeen thousand four hundred ninety crore rupees is the outlay of the SIGHT programme alone, the largest single component, which supports electrolyser manufacturing and green hydrogen production. Option D is wrong because one lakh crore rupees is the saving in fossil fuel imports that the mission projects, not its outlay.

The correct answer is B, Sumio Iijima. The Japanese physicist Sumio Iijima, then at the NEC laboratory, reported multi walled carbon nanotubes in 1991 using a transmission electron microscope, and the date and the name are the facts asked. A nanotube is a sheet of graphene rolled into a cylinder, is about a hundred times stronger than steel for the same weight, and conducts heat and electricity very well. Option A is wrong because Harold Kroto was part of the fullerene discovery of 1985 and shared the Nobel Prize in Chemistry in 1996. Option C is wrong because Andre Geim isolated graphene in 2004 with Konstantin Novoselov at Manchester and shared the Nobel Prize in Physics in 2010. Option D is wrong because Richard Smalley too belongs to the fullerene team of 1985, a related but earlier discovery.

The correct answer is B, At least 5 million metric tonnes a year. The mission aims to build a green hydrogen production capacity of at least five million metric tonnes a year by 2030, with the potential to rise further if an export market develops, and this is the single figure most often asked from the mission. Option A is wrong because one million metric tonnes is well below the stated target. Option C is wrong because fifty million metric tonnes is the quantity of carbon dioxide emissions the mission expects to avert each year, not the hydrogen it expects to produce, and swapping the two is the standard trap. Option D is wrong because one hundred and twenty-five is the figure in gigawatts of renewable electricity capacity that the mission expects to be added alongside, not a tonnage of hydrogen.

The correct answer is C, 2010. Andre Geim and Konstantin Novoselov of the University of Manchester shared the Nobel Prize in Physics in 2010 for groundbreaking experiments on graphene, the single atom thick sheet of carbon they had lifted from graphite with ordinary adhesive tape. Option A is wrong because 2004 is the year of the isolation itself, and the gap between the discovery and the prize is the trap in this question. Option B is wrong because the Nobel Prize in Physics of 2008 went to work on broken symmetry and quarks, with no connection to graphene. Option D is wrong because the Nobel Prize in Physics of 2014 honoured the blue light emitting diode, a different materials achievement. Graphene is the strongest material yet tested, an excellent conductor and almost completely transparent.