Science & Technology Mixed Quiz: Set 14

The correct answer is B, the Department of Science and Technology. The Union Cabinet approved the mission on 19 April 2023 and placed its implementation with that department, which runs it through four thematic hubs at leading academic institutions. Option A is wrong because the Department of Atomic Energy looks after nuclear power, nuclear research centres and related applications, and it is not the nodal agency here. Option C is wrong because the Department of Space, which runs the Indian Space Research Organisation, has demonstrated quantum key distribution of its own but does not implement the mission. Option D is wrong because the Ministry of Electronics and Information Technology runs programmes in semiconductors and artificial intelligence, a separate stream. Learn the pairing of each mission with its nodal department, since that is the usual question format.

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, ethyl alcohol, C2H5OH. Ethanol is the two carbon alcohol obtained by the fermentation of sugars by yeast, and it is the alcohol blended into petrol under the Ethanol Blended Petrol programme. Option A is wrong because methyl alcohol or methanol is a different, single carbon alcohol; it is highly poisonous and is the subject of a separate methanol blending programme, not the ethanol one. Option C is wrong because glycerol is a three carbon trihydric alcohol and in this chapter appears as the by-product of biodiesel manufacture, not as a fuel blend. Option D is wrong because acetic acid is a carboxylic acid, the acid of vinegar, formed when ethanol is oxidised; it is not a fuel. Remember that ethanol also raises the octane number of petrol.

The correct answer is B, Edward Jenner, against smallpox. In 1796 Jenner used material from cowpox, a mild disease of cattle, to protect a boy against smallpox, and the word vaccine itself comes from vacca, the Latin for cow. Option A is wrong in its order rather than in its facts: Louis Pasteur did make a rabies vaccine, but in 1885, almost ninety years later, and he named the method vaccination in honour of Jenner. Option C is wrong because Robert Koch identified the tuberculosis bacterium in 1882 and did not make its vaccine; the BCG vaccine was developed later by Calmette and Guerin, whose names it carries. Option D is wrong; Alexander Fleming discovered penicillin, an antibiotic and not a vaccine, in 1928. Keep the triple of Jenner with 1796, Pasteur with 1885 and Fleming with 1928.

The correct answer is B, 50 to 1,000 physical qubits. This is the headline target stated when the Cabinet approved the mission, and it is to be achieved on more than one hardware platform, including superconducting and photonic technology, rather than on a single design. The range is called intermediate scale because machines of this size are large enough to be useful for research but still too small to run error corrected algorithms at full strength. Option A is wrong because machines of a few dozen qubits already existed worldwide when the mission was framed, so that would be no target at all. Option C is wrong because a thousand is the upper and not the lower end of the stated range. Option D is wrong because no national programme has set a target of tens of thousands of physical qubits for eight years.

The correct answer is C, the number of holes equals the number of electrons. In an intrinsic, that is a chemically pure, semiconductor every free electron is produced by breaking a covalent bond, and breaking a bond leaves behind exactly one hole, so electrons and holes are created strictly in pairs and their concentrations must be equal. Option A is wrong because a product of two concentrations cannot equal a bare number one; the product is fixed by temperature and the band gap, not by unity. Option B is wrong because holes can outnumber electrons only in a p-type crystal, which needs a trivalent dopant. Option D is wrong because electrons outnumber holes only in an n-type crystal, which needs a pentavalent dopant. Equal numbers are therefore the signature of the pure crystal, and any inequality means doping has taken place.

The correct answer is C, paddy straw. Second generation biofuels are made from lignocellulosic biomass that is not food, such as paddy straw, wheat straw, bagasse, cotton stalk and municipal solid waste; the cellulose must first be broken down into fermentable sugars, which makes the process costlier and earns these fuels the name advanced biofuels. Options A and B are wrong because sugarcane juice and maize grain are food or food crop materials and yield first generation ethanol, the ordinary kind. Option D is wrong because edible mustard oil would give first generation biodiesel, and Indian policy avoids edible oils altogether and looks to non-edible seeds like Jatropha instead. India built its first commercial second generation ethanol plant, running on paddy straw, at Panipat in Haryana.

The correct answer is D, 1.6 W/kg. The Specific Absorption Rate measures how much radio energy from a handset the body takes in, in watts per kilogram of tissue. From 1 September 2012 the Department of Telecommunications made 1.6 W/kg, averaged over one gram of human tissue, the limit for every new mobile handset design sold in India. Before that India followed the older figure of 2.0 W/kg averaged over ten grams. The rules also require the SAR value to be printed on the handset and its box, and a buyer can check it by dialling a code given by the maker. India's limit matches the standard used in the United States. Option A is wrong because 1.8 W/kg is not a prescribed limit anywhere. Option B is wrong because 2.1 W/kg is not a SAR standard. Option C is wrong because 2.2 W/kg is only a distractor. Exam tip: India's SAR limit is 1.6 W/kg over 1 gram of tissue, in force from 1 September 2012.

The correct answer is B, the Indian Institute of Science, Bengaluru. The mission divides the field among four thematic hubs, and quantum computing was assigned to the Indian Institute of Science. Option A is wrong because the Indian Institute of Technology Madras hosts the hub for quantum communication, which covers quantum key distribution over fibre and by satellite. Option C is wrong because the Indian Institute of Technology Bombay hosts the hub for quantum sensing and metrology, the branch that produces atomic clocks, magnetometers and gravimeters. Option D is wrong because the Indian Institute of Technology Delhi hosts the hub for quantum materials and devices, which builds the superconductors, topological materials and single photon sources the other three branches depend on. Learn the four as a set, since questions often swap two of them.

The correct answer is B, fast breeder reactors. 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 the programme builds up a stock of fuel for the third stage. Option A is wrong because pressurised heavy water reactors burning natural uranium make up the first stage. Option C is wrong because boiling water reactors were imported for Tarapur and were never part of the staged plan. Option D is wrong because gas cooled reactors have no place in the Indian programme at all. Learn the chain in order: natural uranium, then plutonium with a thorium blanket, then uranium 233 from thorium.

The correct answer is A, compressed bio-gas. SATAT stands for Sustainable Alternative Towards Affordable Transportation and was launched in October 2018 by the Ministry of Petroleum and Natural Gas; under it the oil marketing companies invite entrepreneurs to set up compressed bio-gas plants from agricultural residue, cattle dung and municipal waste and offer to buy the gas for sale at their retail outlets. Option B is wrong because rooftop solar is promoted through separate schemes of the Ministry of New and Renewable Energy. Option C is wrong because nuclear fuel reprocessing is the business of the Department of Atomic Energy and has no connection with biomass. Option D is wrong because green hydrogen has its own National Green Hydrogen Mission. Compressed bio-gas is over ninety per cent methane.

The correct answer is B, plant breeding. Plant breeding is the deliberate improvement of crops by choosing parents with desirable characters, crossing them, selecting among the progeny and multiplying the best lines; the high yielding wheat and rice varieties of the Green Revolution came from it, and modern breeding is often combined with tissue culture and marker assisted selection. Option A is wrong because plant embryology studies the development of the embryo and seed, which is descriptive rather than an improvement programme. Option C is wrong because plant biochemistry studies the chemical reactions inside the plant, such as photosynthesis and secondary metabolites. Option D is wrong because plant anatomy studies internal structure and tissues under the microscope. Breeding works with genes already present in related plants, while genetic engineering can bring a gene from any organism.

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, a derailment caused by a fractured rail. Kavach works on the movement of trains: it reads the position and speed of a locomotive from trackside tags, compares that with the signal and the permitted speed, and brakes the train when the driver does not. It therefore covers options A, B and D, which are all failures of driving or of spacing between trains. It has no way of knowing that a rail has cracked, that a landslide has covered the track or that a coach axle is defective, because it does not inspect the track structure or the rolling stock. Those hazards are addressed by separate measures such as ultrasonic flaw detection of rails, track recording cars and coach maintenance schedules. Examiners set this distinction precisely because Kavach is often described loosely as an anti-accident system.

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 A, the crew module and the service module. The crew module is the pressurised double walled cabin where the astronauts live, and it is the only part that returns to Earth, protected by a heat shield and lowered by parachutes. The service module is an unpressurised section carrying propulsion, power generation, thermal control and other support systems, and it is separated before re-entry.

Option B, lander and rover, describes Chandrayaan-3, where Vikram and Pragyan worked on the Moon. Option C, orbiter and propulsion module, describes the earlier lunar missions, which had to place a spacecraft in lunar orbit. Option D is wrong because the cryogenic stage belongs to the launch vehicle and burns out long before orbit is reached, so it is never part of the spacecraft. Knowing which part comes back is the detail most often tested.

The correct answer is B, factoring large integers. Peter Shor published the algorithm in 1994, and it would let a sufficiently large quantum computer break the large number factorisation on which public key encryption such as the RSA system depends. That threat is the reason governments and standards bodies have begun work on post quantum cryptography. Option A is wrong because searching an unsorted database is the task of Grover's algorithm, published by Lov Grover in 1996, which gives a quadratic rather than an exponential speedup. Option C is wrong because sorting is not a problem on which quantum computers hold any celebrated advantage. Option D is wrong because image compression is a classical signal processing task with no quantum algorithm of this importance. Keep the pair clear: Shor factors, Grover searches.

The correct answer is A, transesterification. In transesterification a vegetable oil or animal fat is made to react with methanol or ethanol in the presence of an alkaline catalyst such as potassium hydroxide, giving fatty acid methyl esters, which are biodiesel, and glycerol as the by-product. Option B is wrong because fractional distillation is how crude petroleum is separated into petrol, kerosene and diesel; it separates an existing mixture instead of making a new ester. Option C is wrong because hydrogenation adds hydrogen across double bonds and is the process that turns liquid oils into vanaspati. Option D is wrong because fermentation is the anaerobic action of yeast on sugars, which is how ethanol and not biodiesel is produced. Pure biodiesel is designated B100, a five per cent blend is B5, and the alkaline catalyst commonly used in the reaction is potassium hydroxide or sodium hydroxide.

The correct answer is B, an unknown quantum state cannot be copied and measuring it disturbs it. The no cloning theorem forbids an exact copy of an unknown state, and any measurement changes the state, so an eavesdropper on the channel inevitably leaves statistical traces that the two legitimate parties detect when they compare a sample of their key. The BB84 protocol of Charles Bennett and Gilles Brassard, proposed in 1984, is built on exactly this. Option A is wrong because double encryption is a classical measure and is not what makes the method secure. Option C is wrong because the speed of the signal has nothing to do with secrecy. Option D is wrong because quantum key distribution runs over ordinary optical fibre and free space links that any receiver can physically access; the security lies in physics, not in hiding the channel.

The correct answer is B, biodiesel. Jatropha curcas yields a non-edible oil seed, and because India cannot spare edible oil for fuel, the National Policy on Biofuels looks to non-edible oils such as Jatropha and Pongamia pinnata, or karanja, along with used cooking oil and animal tallow, as feedstock for biodiesel. Option A is wrong because bioethanol comes from sugar and starch materials, molasses, sugarcane juice, maize and damaged grain, through fermentation. Option C is wrong because biogas is produced by the anaerobic digestion of wet organic waste such as cattle dung, not by pressing an oilseed. Option D is wrong because biochar is the charcoal-like solid left when biomass is heated without air and is used as a soil amendment, not as a liquid fuel.