Current Affairs 3 October 2026: Today's GK & MCQs

The correct answer is A, Abraham Lincoln. Lincoln is the only American President shot inside a theatre, so he is the one the question points to. He was watching a play at Ford's Theatre in Washington on the night of 14 April 1865 when John Wilkes Booth, an actor who backed the defeated Confederacy, fired at him; Lincoln died the next morning. Lincoln was the sixteenth President, led the United States through the Civil War, issued the Emancipation Proclamation of 1863 and was the first American President to be assassinated. B is wrong because John F. Kennedy was shot while riding in an open car in Dallas in 1963. C is wrong because James A. Garfield was shot at a railway station in Washington in 1881. D is wrong because William McKinley was shot at the Pan-American Exposition in Buffalo in 1901. Exam tip: the four assassinated Presidents in order are Lincoln 1865, Garfield 1881, McKinley 1901 and Kennedy 1963.

The correct answer is A, Aluminium manufacturing. Muri, a town in the Ranchi district of Jharkhand, has a large alumina refinery, so it is remembered as an aluminium centre. The works began in 1948 and are now run by Hindalco; they treat bauxite mined on the Lohardaga, Gumla and Palamu plateaus and turn it into alumina, the powder from which aluminium metal is smelted. Bauxite close by, coal-based power from the Damodar valley and a rail link are what put the industry there. B is wrong because copper in this region is smelted at Ghatsila in the Singhbhum copper belt. C is wrong because the steel plants of the area are at Jamshedpur and Bokaro, not Muri. D is wrong because the fertiliser unit of this belt stands at Sindri near Dhanbad. Exam tip: pair the Jharkhand towns - Muri with aluminium, Ghatsila with copper, Jamshedpur and Bokaro with steel, Sindri with fertiliser.

The correct answer is A, Linlithgow. The Joint Parliamentary Committee that examined the White Paper on Indian constitutional reform was chaired by Lord Linlithgow, and its report of 1934 became the draft of the Government of India Act of 1935. The chain a paper setter tests runs in this order: the Simon Commission of 1927, the three Round Table Conferences of 1930 to 1932, the White Paper of March 1933, the Joint Parliamentary Committee under Linlithgow, and then the Act. The same Linlithgow came to India as Viceroy in 1936 and stayed till 1943, so the man who shaped the Act also worked it. B is wrong because Ramsay MacDonald, the British Prime Minister, presided over the Round Table Conferences and announced the Communal Award. C is wrong because Winston Churchill led the Conservative revolt against the bill. D is wrong because Clement Attlee was a member of the Simon Commission and later announced the transfer of power. Exam tip: Linlithgow - Joint Parliamentary Committee 1933-34, then Viceroy 1936-43.

The correct answer is C, the theory of plate tectonics. Plate tectonics says the Earth's rigid outer shell is broken into plates that keep moving slowly, carried by convection currents in the mantle below. The theory took shape in the 1960s, after Harry Hess explained sea-floor spreading, and the term was given by Tuzo Wilson and others. There are seven major plates and many minor ones, moving a few centimetres a year, and almost all earthquakes, volcanoes, fold mountains and deep trenches occur where they meet. A is wrong because Alfred Wegener's continental drift of 1912 moved only the continents and could not name a force strong enough to do it. B is wrong because Pangaea is the name of the single super-continent, not a theory of motion. D is wrong because plate boundaries are the edges where plates meet, a part of the theory and not the theory itself. Exam tip: Wegener gave continental drift in 1912, Hess gave sea-floor spreading in 1960, and plate tectonics followed.

The correct answer is A, 1 and 4. Hooke's law holds only as far as the limit of proportionality, and that limit is either equal to or lower than the elastic limit, so statements 1 and 4 are the correct pair. Hooke's law says stress is proportional to strain, which is the straight part of the stress-strain graph; the point where the curve leaves the straight line is the limit of proportionality. A little beyond it the material still springs back to its original shape, and the last point at which it does so is the elastic limit. For most metals the two points lie very close together and for an ideal material they coincide. B is wrong because statement 2 extends the law past the straight part of the graph, where stress and strain are no longer proportional. C and D are wrong because statement 3 says always less, while the two limits may also be equal. Exam tip: order the four points as proportionality limit, elastic limit, yield point, ultimate stress.

The correct answer is B, Himachal Pradesh. Himachal Pradesh lies west of the Nepal border, so it touches China in the north but never Nepal. Five Indian states share a boundary with Nepal - Uttarakhand, Uttar Pradesh, Bihar, West Bengal and Sikkim - and the border runs for about 1,751 kilometres. Bihar has the longest stretch of it and the Indo-Nepal border is an open one, crossed without a passport or visa under the Treaty of Peace and Friendship of 1950. A is wrong because Uttarakhand meets Nepal along the Kali or Sharda river, with the disputed Kalapani area at its head. C is wrong because Bihar's whole northern plain, from West Champaran to Kishanganj, lies along Nepal. D is wrong because Uttar Pradesh touches Nepal through districts such as Lakhimpur Kheri, Bahraich, Shrawasti, Siddharthnagar and Maharajganj. Exam tip: the five Nepal states from west to east are Uttarakhand, Uttar Pradesh, Bihar, West Bengal and Sikkim.

The correct answer is D, Both the statements are true. Reduction means the loss of oxygen or the gain of hydrogen, so each statement states one half of the same definition. In the older oxygen-hydrogen sense, a substance is oxidised when it gains oxygen or loses hydrogen and reduced when it loses oxygen or gains hydrogen. When copper oxide is heated with hydrogen, the copper oxide loses oxygen and is reduced while the hydrogen gains oxygen and is oxidised, which is why the two always happen together in a redox reaction. The modern electron view says the same thing in another way: reduction is the gain of electrons and a fall in oxidation number. A is wrong because both halves of the definition are standard school chemistry. B is wrong because gaining hydrogen is also reduction, as in ethene turning into ethane. C is wrong because losing oxygen is the oldest test of reduction of all. Exam tip: remember OIL RIG - Oxidation Is Loss, Reduction Is Gain of electrons.

The correct answer is C, Cu + Sn. Bronze is an alloy of copper and tin, usually about 88 per cent copper to 12 per cent tin. Tin makes copper harder and gives it a far better resistance to rust and sea water, which is why bronze is used for statues, temple bells, coins, medals and ship fittings. It was the first alloy people made in quantity and the Bronze Age takes its name from it; the Dancing Girl of Mohenjo-daro is a bronze casting. A is wrong because aluminium with copper, manganese and magnesium is duralumin, a light alloy used in aircraft. B is wrong because copper with zinc is brass, the yellow alloy of utensils and musical instruments. D is wrong because lead with tin is solder, the low-melting alloy used to join wires. Exam tip: fix the three copper alloys - bronze is copper and tin, brass is copper and zinc, German silver is copper, zinc and nickel.

The correct answer is D, Ar and N2. An ordinary filament bulb is filled with a mixture of argon and nitrogen because both are chemically unreactive and will not burn the white-hot tungsten filament. The filament works at about 2,500 degrees Celsius, and in air it would oxidise within seconds. The inert filling also raises the pressure inside the glass, which slows the evaporation of tungsten atoms, so the filament lasts longer and the glass blackens less. Argon is preferred among the noble gases because it is the cheapest, making up nearly one per cent of air. A is wrong because hydrogen is highly inflammable and would be a danger inside a hot bulb. B is wrong for the same reason, as the hydrogen in it makes the mixture unsafe. C is wrong because the oxygen in it would oxidise and break the filament at once. Exam tip: tungsten filament, melting point about 3,400 degrees Celsius, in an argon-nitrogen filling.

The correct answer is C, mRNA copy. Protein synthesis begins with transcription, in which the message of a gene is copied from DNA into messenger RNA, so the first event is the making of an mRNA copy. The mRNA leaves the nucleus, reaches a ribosome in the cytoplasm and is read three bases at a time; each triplet, called a codon, calls for one amino acid, which transfer RNA brings to the ribosome. This second stage is translation, and the chain of amino acids folds into the protein. A is wrong because copying DNA into DNA is replication, which happens before cell division and not during protein synthesis. B is wrong because it is too loose: transfer RNA and ribosomal RNA are also RNA, but the copy that carries the gene's message is mRNA. D is wrong because no DNA copy is made here at all. Exam tip: DNA to RNA is transcription, RNA to protein is translation, DNA to DNA is replication.

The correct answer is D, 17. The 2030 Agenda for Sustainable Development sets 17 Sustainable Development Goals, and these are broken into 169 targets. The United Nations General Assembly adopted the agenda in September 2015 and the goals came into force on 1 January 2016, taking over from the eight Millennium Development Goals that ran from 2000 to 2015. Goal 1 is no poverty, Goal 2 is zero hunger, Goal 13 is climate action and Goal 17 is partnerships for the goals. In India, NITI Aayog tracks them and publishes the SDG India Index. A, B and C are wrong because 19, 15 and 12 are not the count of the goals; 15 and 12 are themselves goal numbers, life on land and responsible consumption, which is the trap in this question. Exam tip: fix the three numbers together - 17 goals, 169 targets, adopted September 2015 for the period up to 2030.

The correct answer is C, fish farming. Pisciculture is the rearing of fish in ponds, tanks and other managed waters, the Latin word piscis meaning fish. It is a branch of aquaculture and India is one of the largest fish producers in the world; the Blue Revolution is the name given to the planned growth of fish output, and rohu, catla and mrigal are the common Indian carps raised in ponds. A is wrong because the rearing of honey bees is apiculture, which gives honey and beeswax. B is wrong because the rearing of silkworms is sericulture, in which the mulberry-fed Bombyx mori gives most of the world's silk. D is wrong because the rearing of birds is aviculture, and the keeping of fowl for eggs and meat is poultry farming. Exam tip: learn the culture words together - pisciculture fish, apiculture bees, sericulture silkworms, aviculture birds, horticulture fruits and vegetables, floriculture flowers.

The correct answer is D, Convex mirror. A convex mirror bulges towards the viewer and always gives a virtual, erect and diminished image, so whatever your distance from it, your reflection looks smaller than you. Because the image is small, the mirror takes in a wide field of view, which is why convex mirrors are fitted as rear-view mirrors on vehicles, at blind corners of roads and in shops as security mirrors. Its focus lies behind the mirror, so it is also called a diverging mirror. A is wrong because a plano-concave surface curves inward like a concave mirror and does not shrink a nearby face. B is wrong because a concave mirror gives a large magnified image of a close object, which is why it is used as a shaving and dentist's mirror. C is wrong because a plane mirror gives an image exactly the same size as the object. Exam tip: convex mirror means always virtual, erect and diminished, with a wide view.

The correct answer is B, 32. Work done is force multiplied by the displacement along the force, so F equals the work divided by the distance, that is 480 joules divided by 15 metres, which gives 32 newtons. The formula to hold is W equal to F into s into the cosine of the angle between them; here the push and the movement are in the same direction, the cosine is one, and the mass of 25 kilograms is extra information that the question setter adds to mislead. One joule is the work done when a force of one newton moves a body one metre. A is wrong because 50 does not divide 480 by 15 and would need the work to be 750 joules. C is wrong because 16 halves the right answer, as if the distance were 30 metres. D is wrong because 25 simply repeats the mass in newtons, which is the trap in the question. Exam tip: W equals F into s, so force equals work divided by distance.

The correct answer is B, 50J. By the work-energy theorem the work done by a force equals the change in kinetic energy, so the work here is half of 4 kilograms times 5 metres per second squared, that is 0.5 into 4 into 25, which gives 50 joules. The body starts from rest, so its initial kinetic energy is zero and the whole of the final kinetic energy has come from the force. Notice that neither the size of the force nor the distance moved is needed; the theorem settles the answer from the masses and speeds alone, which is why it is the quickest route in the exam hall. A is wrong because 40 joules would follow from using the speed once instead of squaring it. C is wrong because 30 joules matches no step of the calculation. D is wrong because 60 joules would need a mass of 4.8 kilograms at the same speed. Exam tip: work equals change in kinetic energy, half m v squared.

The correct answer is B, 40 m. Put the values straight into s equal to u t minus half g t squared, taking upward as positive: 30 into 4 gives 120, half of 10 into 16 gives 80, and the difference is 40 metres. Reading it step by step makes the picture clear. The ball rises for 3 seconds, because 30 divided by 10 is the time to lose all its speed, and in those 3 seconds it climbs 45 metres. In the fourth second it falls back 5 metres, so it is 40 metres above the hand at the end of 4 seconds. A is wrong because 50 metres is the total path length, 45 up plus 5 down, and the question asks for displacement. C is wrong because 30 metres only repeats the initial speed. D is wrong because 15 metres is the height gained in the first second alone. Exam tip: displacement uses u t minus half g t squared, while distance adds the upward and downward paths.

The correct answer is A, 35 m. First find the throwing speed from the height: v squared equals u squared minus 2 g h gives u equal to the square root of 2 into 10 into 80, that is 40 metres per second. The ball therefore takes 4 seconds to reach the top, since 40 divided by 10 is 4. Three seconds of the 7 are left for the fall, and in them the ball drops half of 10 into 9, that is 45 metres. Its height above the start is 80 minus 45, which is 35 metres. B is wrong because 125 metres is the total distance covered, 80 up plus 45 down, not the displacement. C is wrong because 45 metres is only the fall in the last 3 seconds. D is wrong because 25 metres matches no step of the working. Exam tip: time up equals time down, so for a ball reaching 80 metres the flight lasts 8 seconds in all.

The correct answer is C, double. Pliers and scissors are each made of two arms joined at one rivet, and each arm is a complete class 1 lever, so the tool is called a double lever. In a class 1 lever the fulcrum lies between the effort and the load; here the rivet is the fulcrum, the hand on the handle gives the effort and the jaw or blade holds the load. Because two such levers press from opposite sides, the squeeze of one hand acts on both faces of the object at once. A is wrong because there are two arms in the tool, not three. B is wrong because a single lever describes a tool with one arm, such as a crowbar or a see-saw. D is wrong because simple names the whole family of six simple machines and does not say how many levers a tool has. Exam tip: scissors, pliers and pincers are double class 1 levers, while a nutcracker is a double class 2 lever.

The correct answer is D, 2.4. The velocity ratio of a pulley system is the distance moved by the effort divided by the distance moved by the load, so it is 12 divided by 3, that is 4. Efficiency is the mechanical advantage divided by the velocity ratio, so the mechanical advantage is 0.6 multiplied by 4, which gives 2.4. Remember that the velocity ratio depends only on how the machine is built, while the mechanical advantage also falls with friction and with the weight of the pulleys and rope; that is why no real machine reaches an efficiency of 100 per cent and the mechanical advantage is always smaller than the velocity ratio. A is wrong because 4.8 multiplies the velocity ratio by 1.2 instead of 0.6. B is wrong because 3.6 takes 60 per cent of 6, not of 4. C is wrong because 1.2 treats the velocity ratio as 2. Exam tip: efficiency equals mechanical advantage divided by velocity ratio.

The correct answer is B, 10 ohm. For resistors in parallel the reciprocals add, so one over R equals one over 20 plus one over 20, which is 2 over 20, and R comes out as 10 ohms. A short cut worth keeping is that when two equal resistors are joined in parallel the result is half of one of them, and when n equal resistors are joined in parallel it is the value divided by n. The supply of 40 volts is not needed for the resistance; it only tells you that the circuit draws 4 amperes. A parallel joining always gives a resistance smaller than the smallest branch, because the current now has more than one path. A is wrong because 40 ohms is what the two would give in series. C is wrong because 25 ohms follows from no rule of combination. D is wrong because 20 ohms is the value of one resistor alone. Exam tip: series resistances add, parallel resistances add as reciprocals.

The correct answer is C, effort arm length is always less than load arm length. In a class 3 lever the effort is applied between the fulcrum and the load, so the effort always sits nearer the fulcrum and its arm is the shorter of the two. Because mechanical advantage is the effort arm divided by the load arm, a class 3 lever has a mechanical advantage below one: it needs more force than the load, but it gains speed and a longer sweep at the far end. Forceps, sugar tongs, a stapler, a fishing rod and the human forearm lifting a weight are the standard examples. A is wrong because that freedom belongs to a class 1 lever, where the fulcrum may sit anywhere between effort and load. B is wrong because the two arms are equal only in the special class 1 case of a balance. D is wrong because a longer effort arm is the mark of a class 2 lever, such as a nutcracker. Exam tip: class 1 fulcrum in the middle, class 2 load in the middle, class 3 effort in the middle.

The correct answer is A, 0.36 A. Reduce the parallel pair first: 20 into 30 divided by 50 gives 12 ohms. Adding the 8 ohm resistor in series makes the circuit resistance 20 ohms, so the battery drives 12 volts divided by 20 ohms, that is 0.6 ampere, through the whole circuit. That current passes through the 12 ohm combination and drops 0.6 into 12, which is 7.2 volts across it. Both parallel branches share this same 7.2 volts, so the 20 ohm branch carries 7.2 divided by 20, which is 0.36 ampere. B is wrong because 0.12 ampere matches no branch of this circuit. C is wrong because 0.24 ampere is the current in the 30 ohm branch, and the two branch currents add up to 0.6. D is wrong because 0.60 ampere is the total current from the battery, not the share of the 20 ohm resistor. Exam tip: in parallel the voltage is common and the current splits in the inverse ratio of the resistances.

The correct answer is D, Oil in water. Oil does not dissolve in water; it stays as a separate layer or as floating droplets, so the mixture is heterogeneous and the boundary between the two liquids can be seen. A homogeneous mixture has the same composition throughout and its parts cannot be told apart even under a microscope, which is what happens when a solid dissolves in water to give a true solution. Oil and water part because water is a polar liquid while oil is non-polar, and like dissolves like; shaking them with a soap gives an emulsion, which is still not homogeneous. A is wrong because copper sulphate dissolves to give a clear blue solution of one phase. B is wrong because sugar in water is the classic true solution. C is wrong because common salt dissolves completely into sodium and chloride ions. Exam tip: a true solution is homogeneous, while a suspension and an emulsion such as oil in water or milk are heterogeneous.

The correct answer is D, 1 mole of Carbon will contain the same number of atoms as present in 1 mole of Helium. A mole is a count, not a weight: one mole of any element holds 6.022 into 10 to the power 23 atoms, the Avogadro number, whatever the element is. So one mole of carbon and one mole of helium each hold that many atoms. What differs is the mass, because the gram atomic mass is the mass of one mole: one mole of carbon weighs 12 grams while one mole of helium weighs 4 grams, so the carbon sample is three times heavier even though the atom count is equal. A and B are wrong because they turn the three-times ratio of masses into a ratio of atoms. C is wrong for the same reason, only in the reverse direction. Exam tip: a mole is always 6.022 into 10 to the power 23 particles; the atomic mass changes the weight, never the number.

The correct answer is B, 15 moles. The number of moles is the given mass divided by the molar mass, so 60 grams of helium divided by 4 grams per mole gives 15 moles. Helium has an atomic mass of 4, and because it is a noble gas its molecules are single atoms, so its molar mass is 4 grams and not 8. Each of those 15 moles holds 6.022 into 10 to the power 23 atoms, and at standard temperature and pressure the sample would fill about 336 litres, since one mole of any gas takes 22.4 litres. A is wrong because 12 moles uses 5 grams per mole and borrows the 12 of carbon. C is wrong because 10 moles would need a molar mass of 6, which helium does not have. D is wrong because 25 moles would need a molar mass of 2.4, the mass of no element. Exam tip: moles equal mass in grams divided by molar mass, so 4 grams of helium is exactly one mole.

The correct answer is A, Tughlaq. Ghazi Malik was the title of Ghiyasuddin Tughlaq, who founded the Tughlaq dynasty of the Delhi Sultanate in 1320. He was governor of Dipalpur under the Khiljis and won the throne by defeating Khusrau Khan, the usurper who had ended Khilji rule. He built the fortified city of Tughlaqabad near Delhi, and in 1325 his son Muhammad-bin-Tughlaq succeeded him. The dynasty ruled till 1414, and its best known rulers were Muhammad-bin-Tughlaq and Firoz Shah Tughlaq. B is wrong because the Khilji dynasty was founded by Jalaluddin Khilji in 1290 and its strongest ruler was Alauddin Khilji. C is wrong because the Sayyid dynasty was founded by Khizr Khan in 1414, after the Tughlaqs. D is wrong because the Lodi dynasty was founded by Bahlul Lodi in 1451 and was the last dynasty of the Sultanate. Exam tip: keep the order of the five Delhi Sultanate dynasties ready - Slave, Khilji, Tughlaq, Sayyid, Lodi.

The correct answer is A, Tinkathia system. Under the Tinkathia system the indigo planters of Champaran forced every tenant to grow indigo on three kathas out of every twenty kathas of his holding. Gandhi reached Champaran in Bihar in 1917 at the request of the local cultivator Raj Kumar Shukla, and this became his first satyagraha on Indian soil. The government set up an enquiry committee with Gandhi as a member, and the Champaran Agrarian Act of 1918 ended the Tinkathia system and returned part of the illegal dues to the peasants. B is wrong because the Ryotwari system was a land revenue settlement made directly with the cultivator, mainly in Madras and Bombay. C is wrong because slash and burn is a method of shifting cultivation, not an indigo obligation. D is wrong because the Mahalwari system settled revenue with the whole village, chiefly in the North-Western Provinces and Punjab. Exam tip: pair Champaran 1917 with indigo and the Tinkathia system.

The correct answer is C, Inselberg - Glaciers. An inselberg is an isolated residual hill that rises abruptly from a plain in a hot desert, so it is the work of weathering and wind in arid regions, not of glaciers. The German word means island mountain, and the bare rounded domes of arid Africa and of the Jharkhand plateau are the usual examples. Glacial landforms are a different family: cirques, aretes, moraines, drumlins and U-shaped valleys. A is correctly matched because a canyon is a deep, steep-sided gorge cut by a river, the Grand Canyon of the Colorado being the classic case. B is correctly matched because zeugen are table-shaped rock masses carved by wind abrasion in deserts. D is correctly matched because a moraine is rock debris carried and dumped by a glacier. Exam tip: group the desert landforms - zeugen, yardang, inselberg, mushroom rock - against the glacial ones, cirque, moraine and drumlin.

The correct answer is C, C2B. In the consumer-to-business model the consumer names the price or the terms and the business then accepts or declines the offer, so the usual direction of an offer is reversed. Reverse-auction travel sites, where a traveller bids a price for a hotel room, and freelancers who quote their own rate to companies are everyday examples. The model spread with the internet, which let one individual reach many firms at once. A is wrong because B2B commerce is trade between two businesses, such as a parts maker supplying a car factory. B is wrong because B2C commerce is a business selling directly to the end consumer, as a shopping website does. D is wrong because C2C commerce links one consumer with another through a platform, as online classified and resale sites do. Exam tip: read the pair in order - the first letter is who makes the offer, the second is who responds, so in C2B the consumer sets the price.

The correct answer is D, Guru Angad. Guru Nanak, the founder of Sikhism, chose his devoted follower Bhai Lehna as his successor and gave him the name Guru Angad, setting aside the claim of his own sons. Guru Angad became the second Sikh Guru in 1539 and is remembered for giving the Gurmukhi script its present form, the script in which the Sikh scriptures were later written, and for spreading the langar, the free community kitchen. A is wrong because Guru Ram Das was the fourth Guru and is known for founding the city of Amritsar. B is wrong because Guru Amar Das was the third Guru, who came after Guru Angad and not straight after Guru Nanak. C is wrong because Guru Har Rai was the seventh Guru, of a much later period. Exam tip: fix the first three in order - Nanak, Angad, Amar Das - and link Guru Angad with the Gurmukhi script.

The correct answer is D, Ecotone. An ecotone is the transition zone where two different ecosystems meet and mix, such as the belt between a grassland and a forest, an estuary between a river and the sea, or a mangrove strip between land and ocean. It holds species of both neighbouring communities along with a few of its own, so the number of species and their density are often higher in it. This crowding at the edge is called the edge effect, and species found only in such a belt are called edge species. A is wrong because the ecosphere means the whole living world of the earth taken together with its environment. B is wrong because ecoboundary is not a term used in ecology. C is wrong because ecotwin is not an ecological term either. Exam tip: tie ecotone to the edge effect, and keep ecotone, a zone, apart from ecocline, a gradual gradient.

The correct answer is D, Members of a Trade Union. A pressure group is an organised body of people with a shared interest that tries to influence government policy without contesting elections or seeking power itself, so a trade union pressing for better wages is the classic example. Pressure groups work through petitions, strikes, lobbying, publicity and public campaigns; in India business bodies such as FICCI, farmers' organisations, caste associations and student unions act in the same way. A is wrong because members of the Lok Sabha are elected representatives who sit inside the lawmaking body itself. B is wrong because panchayat members are elected office-holders of local self-government. C is wrong because cabinet members form the executive that takes the very decisions a pressure group tries to influence. Exam tip: the line to remember is that a political party seeks power, while a pressure group seeks only influence.

The correct answer is B, Minto-Morley Reforms, 1909. The Indian Councils Act of 1909, known as the Morley-Minto Reforms, introduced separate electorates for Muslims and so gave communal representation legal shape for the first time in British India. Muslim voters elected their own members from separate constituencies, which is why Lord Minto is often called the father of communal electorates. The Act also enlarged the legislative councils and allowed Indians into the executive councils, Satyendra Prasad Sinha becoming the first Indian member of the Viceroy's Executive Council. A is wrong because the Act of 1892 only enlarged the councils and allowed a limited, indirect form of election. C is wrong because the Reforms of 1919 extended separate electorates to Sikhs, Christians, Anglo-Indians and Europeans but did not begin them. D is wrong because the Act of 1935 widened them further, to depressed classes, women and labour. Exam tip: pair 1909 with separate electorates and Minto, and 1919 with dyarchy in the provinces.

The correct answer is D, near the equator. The Inter Tropical Convergence Zone is the low-pressure belt near the equator where the north-east and the south-east trade winds meet. Strong heating by the overhead sun makes the air rise, so surface pressure stays low, winds are light and the sky is cloudy with heavy convectional rain; sailors called this calm belt the doldrums. The zone does not stay fixed: it shifts north in June and July and south in December and January with the apparent movement of the sun, and its northward shift helps the south-west monsoon advance over India. A is wrong because the belt between the trade winds and the westerlies is the subtropical high-pressure belt at about 30 degrees. B is wrong because the belt between the westerlies and the polar winds is the sub-polar low at about 60 degrees. C is wrong because the poles carry permanent high pressure. Exam tip: equatorial low means ITCZ, doldrums and convectional rainfall.

The correct answer is A, Always upright. A pyramid of energy is always upright because energy is lost as heat at every step of a food chain, so each higher trophic level holds less energy than the one below it. Only about ten per cent of the energy at one level passes on to the next, which is Lindeman's ten per cent law, and this flow of energy is one way and can never be reversed. That is why an energy pyramid can never be inverted, while a pyramid of numbers or of biomass sometimes can be: in a pond the biomass of the tiny phytoplankton is smaller than that of the fish feeding on them, and a single large tree supports far more insects than itself. B is wrong because inversion is impossible for energy. C is wrong for the same reason, being the exact opposite. D is wrong because A states the rule correctly. Exam tip: energy pyramid always upright; number and biomass pyramids may invert.

The correct answer is B, Article 338. Article 338 provides for the National Commission for Scheduled Castes, a constitutional body that investigates and monitors the safeguards given to Scheduled Castes, enquires into specific complaints and reports to the President, who places the report before Parliament. The 65th Constitutional Amendment Act of 1990 replaced the earlier Special Officer for Scheduled Castes and Scheduled Tribes with this multi-member Commission, and the 89th Amendment of 2003 divided it, creating a separate National Commission for Scheduled Tribes under Article 338A. A is wrong because Article 332 deals with the reservation of seats for Scheduled Castes and Scheduled Tribes in the state legislative assemblies. C is wrong because Article 342 empowers the President to specify the Scheduled Tribes of a state or union territory. D is wrong because Article 328 concerns a state legislature's power to make laws on elections to its own House. Exam tip: hold the trio together - 338 for SCs, 338A for STs and 338B for backward classes.

The correct answer is C, 1945. The last election to the Central Legislative Assembly set up under the Government of India Act of 1919 was held in the winter of 1945, after the Second World War ended and the Labour government in Britain moved towards a settlement with Indian leaders. The Congress won almost all the general seats and the Muslim League almost all the seats reserved for Muslims, and that verdict shaped the negotiations of 1946, the Cabinet Mission plan and the Constituent Assembly chosen by the provincial legislatures. The Act of 1935 reorganised the provinces, but the central legislature kept working under the 1919 Act until independence. A is wrong because no central election was held in 1930, the year of the Civil Disobedience Movement. B is wrong because the election of 1934 was the previous one, not the last. D is wrong because 1947 brought independence with no fresh central election. Exam tip: link the 1945-46 elections with the sharp communal division before Partition.

The correct answer is B, State Government. Section 16 of the Scheduled Castes and the Scheduled Tribes (Prevention of Atrocities) Act, 1989 extends the collective-fine provision of the Protection of Civil Rights Act, 1955 to atrocities, and the power to impose and recover a collective fine on the inhabitants of an area rests with the State Government. The purpose is to make a whole locality answerable when its people abet an atrocity or shield the offenders, and the inhabitants must be given a chance to be heard before the fine is fixed and apportioned among them. A is wrong because the District Magistrate carries out such orders but is not the authority that imposes the fine. C is wrong because the Special Court tries offences under the Act and punishes individual offenders. D is wrong because the High Court hears appeals and does not levy collective fines. Exam tip: remember the pair - collective fine under Section 16, imposed by the State Government.

The correct answer is A, the expenditure is on interest payments. Interest paid on the government's past borrowing is the classic non-plan expenditure, because it is a committed charge the Centre must meet whatever its plans are.

Until 2017-18 the Union Budget split spending into plan and non-plan expenditure. Non-plan expenditure covered interest payments, defence, subsidies, pensions, salaries, grants to states and relief spending, all routine and committed items that were not tied to a Five Year Plan. Plan expenditure covered outlays on the schemes and projects cleared under the plan. From the 2017-18 Budget the government dropped this split, and spending is now classified only as revenue and capital expenditure.

B is wrong: outlay on science and technology was programme spending and fell under the plan head. C is wrong for the same reason, since money for agriculture went through plan schemes. D is wrong because option A is correct.

Exam tip: non-plan meant committed spending, that is interest, defence, subsidies and pensions, and the plan or non-plan split ended in 2017-18.

The correct answer is A, Indian Nation. The Indian Nation was an English daily brought out from Patna, and it is the only Patna paper in this list.

The paper was started in the 1930s and was run by the Darbhanga Raj, the princely house of north Bihar, which also published the Hindi daily Aryavarta from Patna. For several decades these two were the best known newspapers of Bihar, and questions on the press of the state almost always turn on this pair. Patna has long been a centre of Hindi and English journalism in eastern India.

B is wrong: Punjab Kesari is a Hindi daily of the Hind Samachar group, published from Jalandhar and Delhi. C is wrong: Prabhakar was a nineteenth century Hindi journal of north India, not a Patna daily. D is wrong: Don is not an Indian newspaper at all.

Exam tip: remember the Darbhanga Raj pair published from Patna, The Indian Nation in English and Aryavarta in Hindi.

The correct answer is C, seafloor spreading. New oceanic crust is made at mid-ocean ridges, where magma rises, cools and is pushed outwards on both sides, and that process is called seafloor spreading.

Harry Hess set out the idea in the 1960s. Along a ridge such as the Mid-Atlantic Ridge two plates move apart, basaltic lava fills the gap and hardens into fresh crust, so the rock grows older as you move away from the ridge on either side. The matching magnetic stripes on the two sides of a ridge are the proof of this. The crust destroyed in subduction zones balances the crust created here, which is why the earth does not grow larger.

A is wrong: subduction destroys crust by pushing one plate under another. B is wrong: an earthquake only releases strain that has built up. D is wrong: convection in the mantle drives plate movement but does not itself make crust.

Exam tip: ridges build crust and trenches consume it, so spreading and subduction keep the earth's surface area constant.

The correct answer is A, F. Fluorine is the most electronegative element, so in every compound it pulls the shared electrons towards itself and always shows an oxidation number of -1.

Because no element is more electronegative than fluorine, nothing can take electrons away from it, so it never shows a positive oxidation state. In the free state, as the molecule F2, its oxidation number is zero, which is true of every element in its elemental form, but in a compound the value is fixed at -1. The other halogens are less electronegative, so they can take positive values when they are bonded to fluorine or to oxygen.

B is wrong: chlorine shows +1, +3, +5 and +7 in compounds such as HClO and HClO4. C is wrong: bromine likewise shows +1 and +5, as in HBrO3. D is wrong: iodine shows +1, +5 and +7, as in HIO3.

Exam tip: fluorine is the most electronegative element, so its oxidation number in any compound is always -1.

The correct answer is D, (A), (B) and (C). All three statements describe real features of the Indian Constitution, so all of them have to be counted.

Universal adult suffrage was there from the first general election itself. Article 326 gives the vote to every citizen without any test of property, education, caste or sex, and the voting age was brought down from twenty-one to eighteen by the 61st Amendment. Equality before the law and equal protection of the laws come from Article 14, while Articles 15 and 16 forbid discrimination. At the same time the Constitution allows special provisions for the socially disadvantaged, such as reservation of seats and posts for the Scheduled Castes, the Scheduled Tribes and the backward classes, because real equality needs unequal treatment of the unequal.

Options A, B and C are each wrong because each one of them drops a statement that is in fact a feature of the Constitution.

Exam tip: equality in our Constitution means equality before law plus protective discrimination for the weaker sections.

The correct answer is C. Under the putting out system the merchant handed the raw material to the weaver and took back the finished cloth at a price he himself fixed, which was low.

This is how cloth was produced before factories came up. A merchant or clothier gave yarn, and sometimes the loom as well, to artisans who worked in their own homes, and paid them a piece rate for the cloth. The weaver owned no raw material and had no buyer of his own, so he could not bargain, while the merchant controlled supply, quality and price. In Bengal under the East India Company this hardened into the advance or dadni system, which tied weavers to the Company's agents and ruined many of them.

A is wrong: there was no open bidding, as the merchant set the terms. B is wrong: the cloth was made for the market, not for the weaver's own use. D is wrong: the weaver did not buy yarn in the open market.

Exam tip: putting out means the merchant's raw material, the artisan's home labour and the merchant's price.

The correct answer is A, 82° 30' E longitude. The local time of 82 degrees 30 minutes east is taken as Indian Standard Time for the whole country.

This meridian passes through Mirzapur in Uttar Pradesh. India stretches from about 68 degrees 7 minutes east to 97 degrees 25 minutes east, so the sun rises nearly two hours earlier in Arunachal Pradesh than in Gujarat, and one standard time was fixed to avoid the confusion of many local times. Since each 15 degrees of longitude is worth one hour, and 82 degrees 30 minutes is five and a half times fifteen, Indian Standard Time is exactly five and a half hours ahead of Greenwich.

B is wrong: 82 degrees 50 minutes east is not the chosen line and gives no neat offset. C is wrong: 82 degrees east would make the difference 5 hours 28 minutes. D is wrong: 83 degrees 30 minutes east lies further east and is not used for Indian Standard Time.

Exam tip: 82 degrees 30 minutes east, through Mirzapur, gives IST as five and a half hours ahead of GMT.

The correct answer is A, linguistic and cultural uniformity. The States Reorganisation Act of 1956 redrew the map of India mainly on the basis of language.

The demand for linguistic states grew strong after independence. The death of Potti Sriramulu after a long fast led to the creation of Andhra State in 1953, the first state carved out for the speakers of one language. The government then appointed the States Reorganisation Commission under Fazl Ali, with K M Panikkar and H N Kunzru as its members. Its report was largely accepted, and the Act of 1956, read with the Seventh Amendment, created fourteen states and six union territories in place of the old Part A, B, C and D grouping.

B is wrong: geography and resources were not the test applied. C is wrong: security shaped only a few later changes, not the 1956 scheme. D is wrong: administrative convenience was the colonial basis of provinces, which 1956 replaced.

Exam tip: remember the chain Potti Sriramulu, Andhra 1953, Fazl Ali Commission, States Reorganisation Act 1956.

The correct answer is C, France and Germany. The Maginot Line was the chain of concrete forts that France built along its border with Germany.

It is named after Andre Maginot, the French war minister who pushed the project through, and it was built in the 1930s after the First World War to stop another German invasion. The line was deep, heavily armed and widely thought to be impregnable, but it covered only the German frontier. In 1940 the German army simply went around its northern end through the Ardennes in Belgium and France fell in six weeks, which is why a Maginot Line is now a byword for a defence that is strong in the wrong place.

A is wrong: no such line divides Namibia and Angola. B is wrong: the United States and Canada are separated by the 49th Parallel. D is wrong: the Germany and Poland boundary is the Oder Neisse Line, fixed after the Second World War.

Exam tip: Maginot Line is France and Germany, while the Siegfried Line was Germany's own answering line of defences.

The correct answer is C, oxygen. Photosynthesis makes carbohydrate and gives out oxygen, and of the four choices here only oxygen is something the plant produces.

A green plant uses sunlight trapped by chlorophyll to turn carbon dioxide and water into sugar, and the equation is 6CO2 plus 6H2O giving C6H12O6 plus 6O2. The oxygen comes from the splitting of water in the light reaction, not from carbon dioxide, as experiments with heavy oxygen showed. The glucose made in the dark reaction is stored as starch, and the oxygen escapes through the stomata. This is the source of almost all the oxygen in the air we breathe.

A is wrong: plants do not make hydrocarbons in photosynthesis. B is wrong: carbon dioxide is a raw material taken in, not a product. D is wrong: water too is a raw material and is used up when it is split.

Exam tip: photosynthesis takes in carbon dioxide and water and gives out glucose and oxygen, and the oxygen comes from water.

The correct answer is B, ensure availability and sustainable management of water and sanitation for all. That is the wording of Sustainable Development Goal 6, the water and sanitation goal.

The seventeen Sustainable Development Goals were adopted by the United Nations in September 2015 as part of the 2030 Agenda, and they replaced the eight Millennium Development Goals. Goal 6 covers safe drinking water, sanitation and hygiene, the quality of water bodies, the efficiency of water use and the protection of water related ecosystems such as wetlands. In India the Jal Jeevan Mission and the Swachh Bharat Mission are the flagship programmes usually read against this goal.

A is wrong: good health and well being is Goal 3. C is wrong: no poverty is Goal 1. D is wrong: climate action is Goal 13.

Exam tip: learn the first six goals in order, no poverty, zero hunger, good health, quality education, gender equality and clean water and sanitation.

The correct answer is B, Cholas. Puhar, also called Kaveripattinam, was the great port of the early Cholas of the Sangam age.

The town stood where the Kaveri meets the Bay of Bengal, and Karikala, the best known early Chola ruler, is credited with developing it. Sangam poetry and the Tamil epic Silappadikaram describe its warehouses, its separate quarter for foreign merchants and its trade in pepper, pearls and fine cloth with Rome and South East Asia. Uraiyur was the inland capital of the early Cholas while Puhar served as the coastal capital and port.

A is wrong: the Cheras of the Kerala coast used Muziris and Tondi as their ports. C is wrong: the Pandyas ruled from Madurai and their port was Korkai, famous for pearls. D is wrong: the Vakatakas ruled in the Deccan and had no port on this coast.

Exam tip: pair them up, Chola with Puhar and Uraiyur, Chera with Muziris and Vanji, Pandya with Korkai and Madurai.