Current Affairs 2 October 2026: Today's GK & MCQs

The correct answer is D, Radiation. Radiation carries heat as electromagnetic waves, so it needs no material medium and can travel through a vacuum. This is how the heat of the Sun crosses empty space to reach the Earth, and why you feel warmth in front of a fire without touching it. Every body above absolute zero radiates energy, and the hotter the body, the more it radiates. A is wrong because it pairs radiation with conduction, and conduction cannot work without a medium. B is wrong because in conduction heat passes from particle to particle inside a solid, so a material medium is essential. C is wrong because convection works through the bulk movement of a heated liquid or gas, so it too needs a medium and stops in a vacuum. Exam tip: conduction needs a solid, convection needs a fluid, radiation needs nothing - only radiation crosses a vacuum.

The correct answer is B, Dzongkha. Dzongkha is the national and official language of Bhutan, and it is written in the Tibetan script. The name itself means the language of the dzong, the fortress-monasteries from which Bhutan was governed. Bhutan is a landlocked Himalayan neighbour of India, its capital is Thimphu and its currency is the ngultrum, which is pegged to the Indian rupee. The other three options are all currencies, not languages, which is the trap in this question. A is wrong because the yuan is the currency of China. C is wrong because the ngultrum is the currency of Bhutan, not its language. D is wrong because the kyat is the currency of Myanmar, another neighbour of India. Exam tip: remember the set together - Bhutan, capital Thimphu, language Dzongkha, currency ngultrum.

The correct answer is B, 1517. Ibrahim Lodi came to the throne of Delhi in 1517 after the death of his father Sikandar Lodi. He was the third and last ruler of the Lodi dynasty, which was the final dynasty of the Delhi Sultanate. His harsh treatment of the Afghan nobles turned them against him, and Daulat Khan Lodi, the governor of Punjab, invited Babur to invade India. A is wrong because 1526 is the year Ibrahim Lodi was defeated and killed, not the year he was crowned. C is wrong because by 1527 the Sultanate had already ended and Babur was fighting Rana Sanga at Khanua. D is wrong because Sikandar Lodi was still ruling in 1516. Exam tip: fix the span - Ibrahim Lodi ruled 1517 to 1526, and the First Battle of Panipat in 1526 ended the Delhi Sultanate and began Mughal rule.

The correct answer is C, milk. The White Revolution is the name given to the sharp rise in milk production in India, so the colour white here stands for milk. It began with Operation Flood, launched in 1970 by the National Dairy Development Board, which linked village milk cooperatives to city markets and cut out the middleman. Verghese Kurien, often called the Father of the White Revolution in India, built the Amul model in Anand, Gujarat that the programme spread across the country, and India grew into the largest milk producer in the world. A is wrong because a rise in foodgrain and crop output is the Green Revolution. B is wrong because the rise in fish production is called the Blue Revolution. D is wrong because leather and non-conventional energy are tied to other colour revolutions, not the white one. Exam tip: white is milk, green is foodgrains, blue is fish and yellow is oilseeds.

The correct answer is D, Harshavardhana. Hiuen Tsang, the Chinese Buddhist pilgrim, travelled in India in the seventh century, when Harshavardhana of the Pushyabhuti dynasty ruled from Kannauj. He came in search of Buddhist texts, studied at Nalanda university and left an account of his travels in the Si-Yu-Ki, which is one of our main sources for Harsha and for everyday life of that age. He is remembered as the Prince of Pilgrims. A is wrong because Ashoka ruled in the third century BCE, about nine hundred years earlier. B is wrong because Samudragupta of the fourth century CE is described in the Allahabad Pillar inscription of Harisena, not by a Chinese traveller. C is wrong because Chandragupta I founded Gupta power in the fourth century CE, also long before this visit. Exam tip: pair the visitors - Fa-Hien with Chandragupta II and Hiuen Tsang with Harshavardhana.

The correct answer is C, Hydrochloric acid. Muriatic acid is the old trade name for hydrochloric acid, the water solution of hydrogen chloride gas, and the name survives in the market for the crude commercial grade used for cleaning metal and masonry. It is a strong mineral acid that makes chlorides, and industry uses it in fertilizers and dyes, in electroplating and pickling of steel, and in the photographic, textile and rubber trades. Dilute hydrochloric acid is also present in human gastric juice, where it helps digestion. A is wrong because perchloric acid is HClO4, a powerful oxidising acid with no such common name. B is wrong because sulphuric acid, H2SO4, was once called oil of vitriol, not muriatic acid. D is wrong because nitric acid, HNO3, carried the old name aqua fortis. Exam tip: learn the old names - muriatic acid is HCl, oil of vitriol is H2SO4 and aqua fortis is HNO3.

The correct answer is B, Muhammad Bin Tughlaq. Ibn Batuta, the Moroccan traveller, reached Delhi in the fourteenth century during the reign of Muhammad Bin Tughlaq, who appointed him the qazi of Delhi and later sent him as an envoy to China. His travel account, the Rehla, written in Arabic, describes the Sultan, the court and the roads, markets and postal system of the time, and it is a key source for the Tughlaq period. A is wrong because Alauddin Khalji died in 1316, before this visit. C is wrong because Ibrahim Lodi ruled two centuries later, from 1517 to 1526. D is wrong because Firuz Shah Tughlaq came to the throne in 1351, after Ibn Batuta had already left the Sultan court. Exam tip: tie the traveller to the ruler - Ibn Batuta with Muhammad Bin Tughlaq, and his book is the Rehla.

The correct answer is C, High Yielding Variety. The Green Revolution rested on high yielding variety seeds, usually shortened to HYV seeds, which gave far more grain per hectare than the older local varieties when used with assured irrigation, chemical fertilizers and pesticides. The programme began in the mid 1960s with dwarf wheat and rice, and Punjab, Haryana and western Uttar Pradesh gained the most. M. S. Swaminathan is called the Father of the Green Revolution in India, and the work of Norman Borlaug on dwarf wheat lay behind it. A and B are wrong because the seeds were chosen for the size of the harvest, not for the nutrition in the grain. D is wrong because low yielding seeds are the opposite of what the programme needed. Exam tip: Green Revolution means HYV seeds plus irrigation plus fertilizers, wheat first and Punjab leading.

The correct answer is B, Mercury. Cinnabar is mercuric sulphide, HgS, and the formula itself gives the answer away because Hg is the symbol of mercury. It is the chief ore of mercury, a brick red mineral that is roasted in air to free the metal, and the same mineral ground fine was the old pigment vermilion. Mercury is the only metal that is liquid at room temperature, which is why it was long used in thermometers and barometers. A is wrong because aluminium is obtained from bauxite, its oxide ore. C is wrong because gold occurs mostly in the native state, and calaverite is a minor gold ore. D is wrong because silver comes from ores such as argentite, which is silver sulphide. Exam tip: read the formula first - Hg in HgS means mercury, and remember bauxite for aluminium and argentite for silver.

The correct answer is B, Uttar Pradesh. Aram Bagh stands in Agra in Uttar Pradesh, on the left bank of the Yamuna across from the Taj Mahal, and it is held to be the oldest Mughal garden in India. Babur laid it out soon after 1526 in the Persian charbagh plan, a walled garden cut into four parts by water channels, and it is also called Ram Bagh and Bagh-i-Nur-Afshan. Tradition says the body of Babur rested here before it was carried to Kabul, and Nur Jahan later repaired the garden. A is wrong because Babur built this garden at Agra, which was his capital, not at Delhi. C and D are wrong because neither Madhya Pradesh nor Bihar has this monument. Exam tip: remember the chain - Aram Bagh is at Agra, built by Babur, the first Mughal garden in the charbagh style.

The correct answer is B, 8. The B complex is a group of eight water soluble vitamins that work mainly as helpers in the reactions that release energy from food. They are B1 thiamine, B2 riboflavin, B3 niacin, B5 pantothenic acid, B6 pyridoxine, B7 biotin, B9 folic acid and B12 cyanocobalamin. They were first taken to be one substance and were separated later, which is why the numbers have gaps. Being water soluble, they are not stored in the body for long and must come from the diet, so a shortage shows up quickly as beriberi from B1, pellagra from B3 or anaemia from B12. A, C and D are wrong because six, seven and five fall short of the group, which is complete only at eight members. Exam tip: the B complex has eight vitamins, and B12 is the one that holds cobalt.

The correct answer is C, Gopala. Gopala founded the Pala dynasty in Bengal in the middle of the eighth century, and the Khalimpur copper plate records that he was raised to the throne by the chiefs to end a long spell of disorder known as matsyanyaya, the rule of the fish. The Palas were patrons of Buddhism, and the universities of Vikramshila and Somapura Mahavihara grew under them. A is wrong because Dharmapala was the son of Gopala, who widened the empire and took part in the tripartite struggle for Kannauj. B is wrong because Mahipala I ruled much later and only revived Pala power for a time. D is wrong because Ramapala was one of the last strong Pala kings and is praised in the Ramacharitam of Sandhyakar Nandi. Exam tip: the order of the line is Gopala, then Dharmapala, then Devapala.

The correct answer is C, Vitamin C. Only vitamin C and the eight vitamins of the B complex dissolve in water; the rest dissolve in fat. Vitamin C, chemically ascorbic acid, is not stored in the body, so the extra amount leaves in the urine and the diet must supply it every day through amla, guava, citrus fruits and green vegetables. A shortage causes scurvy, with bleeding gums and slow healing of wounds, and the vitamin is easily destroyed by heat during cooking. A, B and D are wrong because vitamins D, A and K are fat soluble, are stored in the liver and fatty tissue, and can build up to harmful levels if taken in excess. Their deficiencies give rickets, night blindness and poor clotting of blood in that order. Exam tip: water soluble means C and the B group, so the fat soluble four are A, D, E and K.

The correct answer is C, Mahila Samriddhi Yojna. It is the micro-finance scheme under which women borrow small sums at a concessional rate of interest, so the rebate in interest is built into the scheme itself. It is run by the National Backward Classes Finance and Development Corporation under the Ministry of Social Justice and Empowerment, and the money reaches women through State Channelising Agencies and self-help groups, mostly for petty trade and self-employment. A parallel scheme is run for Scheduled Caste women by the National Scheduled Castes Finance and Development Corporation. Option A is wrong because the National Maternity Benefit Scheme paid a one-time cash grant to poor pregnant women and was later merged into Janani Suraksha Yojana. Option B is wrong because it is a pilot for social security cover, not a credit scheme for women. Option D is wrong because Raj Rajeshwari Mahila Kalyan Yojana is a personal accident insurance cover for women, not a loan. Exam tip: Mahila Samriddhi Yojana means micro-credit for women at a concessional interest rate, run by NBCFDC.

The correct answer is D, 301. A 301 reply means Moved Permanently: the page now lives at a new address and the browser or search engine should use that address from now on. HTTP status codes come in classes. Codes in the 200s mean success, the 300s mean redirection, the 400s mean the client made a mistake and the 500s mean the server failed. Because 301 is permanent, browsers remember it and search engines pass the old page's standing to the new address, which is why a website uses 301 when a web address changes for good. Option A is wrong because 500 is Internal Server Error, a fault on the server side. Option B is wrong because 302 is Found, a temporary redirect, so clients keep asking the old address. Option C is wrong because 404 is Not Found, which means no page exists at that address at all. Exam tip: 301 permanent redirect, 302 temporary redirect, 404 not found, 500 server error.

The correct answer is A, 1962. The Sino-Indian War was fought between 20 October and 21 November 1962, when China attacked across the Himalayan frontier. The fighting ran in two separate theatres, Aksai Chin in Ladakh in the west and the North East Frontier Agency, today Arunachal Pradesh, in the east. China declared a unilateral ceasefire on 21 November 1962 and kept Aksai Chin. Jawaharlal Nehru was Prime Minister and the reverses cost Defence Minister V. K. Krishna Menon his post; the war pushed India to enlarge its army and raise mountain divisions trained for high altitude. Option B is wrong because no India-China war took place in 1969. Option C is wrong because 1973 is remembered for the Kesavananda Bharati judgment and the launch of Project Tiger, not a war. Option D is wrong because 1964 is the year Nehru died. Exam tip: 1962 with China, 1965 and 1971 with Pakistan, 1999 Kargil.

The correct answer is D, direct change of a substance from a solid to a gas state. Sublimation is the change from solid to vapour without passing through the liquid stage. It happens when particles of the solid gain enough energy to escape straight into the gas phase, and the reverse change, gas to solid, is called deposition. Camphor, naphthalene balls, iodine, ammonium chloride and solid carbon dioxide, or dry ice, sublime on heating, which is why mothballs shrink away without leaving a wet patch. Chemists use sublimation to purify such solids by separating them from non-volatile impurities. Option A is wrong because a gas changing into a liquid is condensation. Option B is wrong because a gas changing straight into a solid is deposition. Option C is wrong because a liquid changing into a gas is vaporisation or evaporation. Exam tip: solid to gas is sublimation, gas to solid is deposition, and camphor is the stock example.

The correct answer is C, Kumarasambhava. The name itself means the birth of Kumara, that is Kartikeya, the son of Shiva and Parvati, and the poem tells how Shiva and Parvati were married and how their son was born to kill the demon Taraka. Kalidasa, the Sanskrit poet usually placed in the Gupta age, left two long poems, Kumarasambhava and Raghuvamsa, two shorter poems, Meghaduta and Ritusamhara, and three plays, Abhijnanashakuntalam, Vikramorvashiyam and Malavikagnimitram. Option A is wrong because Meghaduta is a lyric in which a banished yaksha sends a message to his wife through a passing cloud. Option B is wrong because Raghuvamsa traces the line of King Raghu, the dynasty into which Rama was born. Option D is wrong because Ritusamhara describes the six seasons of the Indian year. Exam tip: Kumarasambhava is the birth of Kartikeya and Raghuvamsa the dynasty of Raghu, both by Kalidasa.

The correct answer is A, High-Yielding Varieties Programme. HYVP was launched in 1966-67 and it carried the Green Revolution into Indian fields by spreading dwarf, high-yielding seeds. It covered five crops, wheat, rice, maize, jowar and bajra, and the seed came with a package of assured irrigation, chemical fertiliser, pesticides and farm credit, which is why the change is called the seed-fertiliser-water technology. Punjab, Haryana and western Uttar Pradesh gained the most, and wheat output rose fastest, so the early Green Revolution is often called a wheat revolution. Norman Borlaug supplied the Mexican dwarf wheat varieties and M. S. Swaminathan led the work in India. Option B is wrong because the P in the name stands for Programme, not Plants. Option C is wrong because Pattern is not part of the name. Option D is wrong because the programme had nothing to do with patents on seed. Exam tip: HYVP began in 1966-67, covered five crops, and wheat gained the most.

The correct answer is D, Jhelum. Alexander and Porus fought the Battle of Hydaspes in 326 BCE on the banks of the Jhelum, the river the Greeks called Hydaspes and the Rig Veda calls Vitasta. Porus was the Paurava king who ruled the land between the Jhelum and the Chenab; he fought with war elephants and lost, but Alexander was so struck by his bearing that he gave the kingdom back to him and kept him as an ally. This was Alexander's last great battle in India, for his tired soldiers refused to march beyond the Beas and he turned homewards. Option A is wrong because the Parushni, today the Ravi, was the river of the Battle of Ten Kings in the Rig Veda. Option B is wrong because Alexander only crossed the Indus to enter Punjab. Option C is wrong because he never reached the Ganga at all. Exam tip: Hydaspes is the Jhelum, Alexander against Porus, 326 BCE.

The correct answer is A, Land transfers. The Fifth Schedule lets the Governor make regulations for the peace and good government of a Scheduled Area, and it names three matters such a regulation may cover: it may prohibit or restrict the transfer of land by or among members of the Scheduled Tribes, regulate the allotment of land to them, and regulate money-lending to them. The purpose is to stop outsiders from buying up tribal land, so land alienation is the heart of the provision. A regulation of this kind needs the assent of the President, and the Governor must also report to the President every year on the administration of these areas, advised by a Tribes Advisory Council. Option B is wrong because taxation is settled by Parliament and the state legislature, not by such a regulation. Option C is wrong because freedom of speech is a fundamental right no Governor's regulation can curtail. Option D is wrong because water use is not one of the three listed matters. Exam tip: Fifth Schedule regulations cover land transfer, land allotment and money-lending.

The correct answer is B, NHB. The National Housing Bank is one of the central nodal agencies through which the Centre passes the interest subsidy of the Credit Linked Subsidy Scheme of Pradhan Mantri Awas Yojana (Urban) down to the lenders. NHB settles the claims of housing finance companies and other primary lending institutions, HUDCO acts as the nodal agency for the rest, and the subsidy is credited upfront to the borrower's loan account so that the monthly instalment falls. NHB was set up in 1988 as the apex institution for housing finance in India; the regulation of housing finance companies moved to the Reserve Bank in 2019, but NHB still refinances them. Option A is wrong because CNA is only the abbreviation for central nodal agency, not an institution. Option C is wrong because a scheduled commercial bank lends under the scheme but does not route the subsidy. Option D is wrong because NABARD is the apex body for rural and agricultural credit. Exam tip: the PMAY Urban subsidy flows through NHB and HUDCO; NHB was set up in 1988.

The correct answer is B, 1.5055 × 10²³. One mole of any gas occupies 22.4 litres at STP, so 5.6 litres is 5.6 divided by 22.4, that is one quarter of a mole. A mole contains 6.022 × 10²³ particles, the Avogadro number, so a quarter of a mole of oxygen contains 6.022 × 10²³ divided by four, which works out to 1.5055 × 10²³ molecules. Note that the question asks for molecules; since oxygen is diatomic, the number of atoms would be twice this figure. Option A is wrong because 6.022 × 10²³ is the count for a full mole, that is for 22.4 litres. Option C is wrong because 2.24 × 10²³ comes from confusing the molar volume 22.4 with the particle count. Option D is wrong because 3.011 × 10²³ is half a mole, which would be 11.2 litres. Exam tip: at STP, 22.4 litres equals one mole equals 6.022 × 10²³ molecules, so divide the given volume by 22.4 first.

The correct answer is A, province. In the Gupta and post-Gupta period the empire was divided into bhuktis, which were provinces, and inscriptions call the governor of a bhukti an uparika or uparika-maharaja, usually a prince or a trusted noble. A bhukti was split into vishayas, or districts, each under a vishayapati, and below them came the vithi and then the village, where the gramika and the village elders worked. Some records call the same unit a desha or a rashtra. The Gupta habit of granting land and whole villages to brahmins and officers slowly turned these charges into hereditary holdings, a step towards the feudal pattern of early medieval India. Option B is wrong because the land tax of the period was bhaga or bhoga, not bhukti. Option C is wrong because the officer in charge was the uparika, while bhukti was the territory he held. Option D is wrong because a king was called raja or maharajadhiraja. Exam tip: bhukti province, vishaya district, vithi sub-division, grama village.

The correct answer is D, Advocate General. Article 165 of the Constitution says the Governor shall appoint a person qualified to be a judge of a High Court as the Advocate General of the state, and he is the highest law officer of the state, the counterpart of the Attorney General at the Centre. He advises the state government on legal matters, appears for the state in the High Court and the Supreme Court, and has the right to speak in and take part in the proceedings of the state legislature, though he cannot vote in it. He holds office during the pleasure of the Governor, and the Constitution fixes neither his term nor his salary. Option A is wrong because legal adviser is a loose description and not a constitutional post. Option B is wrong because the Attorney General, under Article 76, is the highest law officer of the Union. Option C is wrong because the Law Secretary is a civil servant heading a department. Exam tip: Article 76 Attorney General for the Union, Article 165 Advocate General for a state.

The correct answer is B, Stoichiometry. Stoichiometry is the branch of chemistry that measures how much of each reactant is used up and how much of each product is formed in a reaction, working from the balanced chemical equation. The coefficients of a balanced equation give the ratio in moles, and from that ratio a chemist can work out masses, volumes of gases and numbers of particles, identify the limiting reagent and calculate the percentage yield. The word comes from the Greek stoicheion, meaning element, and metron, meaning measure. Option A is wrong because mole fraction is the ratio of the moles of one component to the total moles in a mixture, a way of stating concentration. Option C is wrong because mass per cent gives the mass of a component present in 100 units of mass of the solution. Option D is wrong because molarity is the number of moles of solute dissolved in one litre of solution. Exam tip: stoichiometry works from the balanced equation, while mole fraction, molarity and mass per cent only express concentration.

The correct answer is D, Coal India Limited. Coal India, the largest coal producing company in the world, was granted Maharatna status in 2011 and remains on the list. Maharatna is the highest grade given to a central public sector enterprise, and the Department of Public Enterprises grants it only to a company that is already a Navratna, is listed on a stock exchange with the required public shareholding, and has a very large three-year average turnover, net worth and net profit. The grade matters because the board of a Maharatna can invest far larger sums in a single project on its own, without going back to the ministry for approval. Option A is wrong because Central Coalfields Limited is a subsidiary of Coal India and holds a much lower grade. Option B is wrong because Cochin Shipyard is a shipbuilder of a lower grade, not a Maharatna. Option C is wrong because the India Tourism Development Corporation is a small enterprise that has been shrinking through disinvestment. Exam tip: Maharatna status needs Navratna status plus stock market listing, and Coal India received it in 2011.

The correct answer is A, Article 350-B. The Seventh Constitutional Amendment Act, 1956 inserted this article on the recommendation of the States Reorganisation Commission and created the office of the Special Officer for Linguistic Minorities, known in practice as the Commissioner for Linguistic Minorities. The President appoints the Commissioner, whose duty is to investigate all matters relating to the safeguards the Constitution provides for linguistic minorities and to report to the President, who has the report laid before each House of Parliament and sent to the state governments concerned. The office works under the Ministry of Minority Affairs. Article 350-A, added by the same amendment, asks states to provide primary education in the mother tongue. Option B is wrong because there is no Article 315-B; Article 315 deals with public service commissions. Option C is wrong because Article 338-A set up the National Commission for Scheduled Tribes. Option D is wrong because Article 348 deals with the language of the Supreme Court and the High Courts. Exam tip: 350-A mother tongue teaching and 350-B Commissioner for Linguistic Minorities, both from the Seventh Amendment, 1956.

The correct answer is B, Emulsification. Mayonnaise is an emulsion: very small droplets of oil are beaten into a watery liquid of egg yolk with vinegar or lemon juice, and the droplets stay spread out instead of separating into a layer. Oil and water do not mix on their own, so such a mixture needs an emulsifying agent, and here it is the lecithin of the egg yolk, whose molecules have one end that likes water and another that likes oil, so they coat each droplet and keep it away from its neighbours. Milk is a natural emulsion of fat in water, and butter is an emulsion of water in fat. Option A is wrong because caramelisation is the browning of sugar on strong heating. Option C is wrong because the Maillard reaction is the browning of a protein with a reducing sugar that gives bread crust and roasted meat their colour. Option D is wrong because oxidation of fat turns it rancid. Exam tip: mayonnaise is oil in water held together by the lecithin of egg yolk, an emulsion.

The correct answer is A, stagflation. Stagflation is the awkward state in which prices keep rising while output stagnates and unemployment stays high, so the usual trade-off between inflation and unemployment breaks down. The word joins stagnation and inflation and came into wide use in the 1970s, when the oil shock pushed up costs across the industrial world and growth fell at the same time. A supply shock is the common cause: costlier oil, food or imports raise prices while production and jobs shrink. It is hard to treat, because tightening money to curb prices deepens the slump, while spending to revive jobs feeds the price rise. Option B is wrong because an inflation premium is the extra interest a lender charges to make up for expected inflation. Option C is wrong because an inflationary gap is the excess of demand over the output an economy can produce at full employment. Option D is wrong because reflation is deliberate policy action to lift demand and prices after a slump. Exam tip: stagflation equals high inflation plus high unemployment, usually caused by a supply shock.

The correct answer is A, Special Officer for Linguistic Minorities. Article 350-B provides that there shall be a Special Officer for Linguistic Minorities appointed by the President, and the post is known in practice as the Commissioner for Linguistic Minorities. His work is to investigate all matters relating to the safeguards the Constitution gives linguistic minorities and to report to the President, who has the reports laid before Parliament and sent to the states concerned. A linguistic minority here means a group whose mother tongue differs from the principal language of the state, and the safeguards include teaching in the mother tongue at the primary stage under Article 350-A and the right to submit a representation to an authority in one's own language under Article 350. Option B is wrong because Scheduled Castes have the National Commission under Article 338. Option C is wrong because the Constitution provides no such special officer for women and children. Option D is wrong because Other Backward Classes have the National Commission under Article 338-B. Exam tip: Article 350-B, Commissioner for Linguistic Minorities, appointed by the President, added by the Seventh Amendment.

The correct answer is C, Depreciation. The circular flow of income in a simple economy has only two sectors, households and firms, and it shows two streams running in opposite directions. Households supply land, labour, capital and enterprise to firms and receive factor payments, that is rent, wages, interest and profit; they spend that income on the goods and services the firms produce, and the money returns to the firms. So factor services, factor payments, goods and services and consumption spending all belong to the flow. Depreciation is the wearing out of machines and buildings, a cost that enters the picture only when the model is widened to saving and capital, which is why gross and net measures of income differ by it. Option A is wrong because factor payments are the income stream of the flow. Option B is wrong because goods and services are the real flow from firms to households. Option D is wrong because spending by households is what closes the circle. Exam tip: in a two-sector flow the real flow runs one way and the money flow the other, and depreciation is not part of it.

The correct answer is A, Maldives. BIMSTEC, the Bay of Bengal Initiative for Multi-Sectoral Technical and Economic Cooperation, has seven members: Bangladesh, Bhutan, India, Myanmar, Nepal, Sri Lanka and Thailand. The Maldives is not one of them, although it is a member of SAARC. The grouping began at Bangkok in 1997 as BIST-EC with Bangladesh, India, Sri Lanka and Thailand; Myanmar joined later the same year, and Nepal and Bhutan came in 2004, when the present name was adopted. Its permanent secretariat is at Dhaka, and because it links five South Asian with two South-East Asian countries, it is often described as a bridge between South Asia and South-East Asia. Option B is wrong because India is a founding member. Option C is wrong because Bhutan joined in 2004. Option D is wrong because Nepal also joined in 2004. Exam tip: BIMSTEC has seven members with no Pakistan, Afghanistan or Maldives, and its secretariat is at Dhaka.

The correct answer is B, two weeks. By the middle of 1991 India's foreign exchange reserves had fallen to about one billion dollars, enough to pay for only about two weeks of imports, and the country stood close to default on its external payments. The Gulf War had pushed up oil prices and cut remittances from West Asia, the fiscal deficit was wide and short-term borrowing had piled up. India pledged gold with the Bank of England and the Bank of Japan, borrowed from the International Monetary Fund, and devalued the rupee in two steps in July 1991. The crisis forced the New Economic Policy of liberalisation, privatisation and globalisation, announced under Prime Minister P. V. Narasimha Rao with Manmohan Singh as Finance Minister. Option A is wrong because three months of import cover is the comfortable level, not the level in the crisis. Option C is wrong because one month overstates the reserves then held. Option D is wrong because reserves had not fallen to a single week of imports. Exam tip: 1991 crisis, two weeks of import cover, gold pledged abroad, rupee devalued, reforms began.

The correct answer is A, The Hague. The International Court of Justice sits in the Peace Palace at The Hague in the Netherlands, and it is the only principal organ of the United Nations not based in New York. Set up by the UN Charter in 1945, it held its first sitting in 1946 and took the place of the Permanent Court of International Justice of the League of Nations. It has fifteen judges elected for nine years by the General Assembly and the Security Council voting separately, and it both decides disputes between states and gives advisory opinions to organs of the United Nations. Option B is wrong because Paris is the headquarters of UNESCO. Option C is wrong because Washington DC houses the International Monetary Fund and the World Bank. Option D is wrong because New York is the seat of the United Nations itself, with the General Assembly and the Security Council. Exam tip: the ICJ sits at The Hague with fifteen judges for nine-year terms, the one principal UN organ outside New York.

The correct answer is C, First Amendment Act. The Ninth Schedule was inserted by the Constitution (First Amendment) Act, 1951, to shield land reform laws from being struck down by the courts. The same amendment added Article 31B, which says that a law placed in the Ninth Schedule cannot be questioned for taking away a fundamental right. The Schedule started with 13 entries, mostly the zamindari abolition laws of the states, and has grown far beyond that. The protection is no longer absolute: in I. R. Coelho v. State of Tamil Nadu (2007) the Supreme Court held that laws added after 24 April 1973 can still be tested against the basic structure of the Constitution. Option A is wrong because the Third Amendment of 1954 reworked the Concurrent List entry on essential commodities. Option B is wrong because the Fourth Amendment of 1955 only put more laws into a Schedule that already existed. Option D is wrong because the Sixth Amendment of 1956 dealt with taxes on the inter-State sale of goods. Exam tip: First Amendment, 1951 — Ninth Schedule along with Article 31B.

The correct answer is C, they are appointed by the Governor in consultation with the High Court of the concerned State. This is the rule laid down in Article 233 of the Constitution. Appointment, posting and promotion of district judges in a state are made by the Governor, who must consult the High Court that exercises jurisdiction over that state. A person not already in government service can be appointed only if they have practised as an advocate or pleader for at least seven years and are recommended by the High Court. Article 234 covers other judicial officers, who are appointed by the Governor from the state judicial service as per rules framed after consulting the High Court and the State Public Service Commission. Option A is wrong because the High Court is only consulted; its Chief Justice does not appoint. Option B is wrong because the President appoints judges of the Supreme Court and the High Courts, not district judges. Option D is wrong because the Supreme Court has no role here. Exam tip: Article 233 — Governor appoints, High Court is consulted.

The correct answer is D, Dual Government. A dual government, one at the centre and one in the units, is the common feature of every federation, so India and the USA do not differ on this point. Both countries divide powers between a national government and state governments through a written constitution, and both let courts settle disputes about that division. The other three features are exactly where the two systems part company, because India has a federation with a strong unitary bias. Option A is wrong because every American state sends two members to the Senate regardless of size, while seats in the Rajya Sabha are allotted according to a state’s population, so representation is unequal. Option B is wrong because an American citizen is a citizen of both the Union and a state, while India gives only single citizenship. Option C is wrong because the USA has separate federal and state courts, while India has one integrated judiciary headed by the Supreme Court. Exam tip: India — single citizenship, integrated judiciary, unequal Rajya Sabha seats.

The correct answer is B, Emerald. Emerald is the deep green variety of the mineral beryl, a beryllium aluminium silicate, so beryllium is part of its very formula. Traces of chromium, and sometimes vanadium, give the stone its green colour. Beryl is the chief ore of beryllium, a light, stiff metal used in X-ray windows, aerospace alloys and nuclear reactors; aquamarine is the pale blue variety of the same mineral. Option A is wrong because topaz is an aluminium silicate carrying fluorine and hydroxyl groups, with no beryllium in it. Option C is wrong because ruby is corundum, that is aluminium oxide, which turns red because of chromium impurity. Option D is wrong because blue sapphire is the same corundum, coloured blue by traces of iron and titanium. So ruby and sapphire are two colours of one mineral, while emerald belongs to a different family altogether. Exam tip: emerald = beryl (beryllium); ruby and sapphire = corundum (aluminium oxide).

The correct answer is C, President of India after an address in both Houses of Parliament. Under Article 148 the Comptroller and Auditor-General is appointed by the President by warrant under his hand and seal, but can be removed only in the same manner and on the same grounds as a judge of the Supreme Court. That means each House must pass an address by a special majority on the ground of proved misbehaviour or incapacity, and only then does the President remove him. This difficult procedure, along with a fixed term of six years or age 65, a salary charged on the Consolidated Fund of India and a bar on holding any further office of profit, is what keeps the CAG independent while he audits the accounts of the Union and the states. Option A is wrong because the Council of Ministers cannot advise his removal. Option B is wrong because the Chief Justice has no power to remove him. Option D is wrong because the advice of the Chief Justice is not the route either. Exam tip: Article 148 — CAG is removed exactly like a Supreme Court judge.

The correct answer is A, the Arabian Sea exhibits a high rate of evaporation and a low influx of fresh water. Salinity rises where water leaves as vapour and falls where fresh water is added. The air over the Arabian Sea is dry and hot, evaporation is heavy, rainfall is modest and the only large river reaching it is the Indus, so the salt that stays behind keeps surface salinity around 36 parts per thousand. The Bay of Bengal gets the Ganga, Brahmaputra, Mahanadi, Godavari and Krishna along with very heavy monsoon rain, and all that fresh water dilutes it to about 33 parts per thousand. Option B is wrong because the Arabian Sea is in fact the deeper of the two basins, and depth by itself does not decide salinity. Option C is wrong because the Bay of Bengal is the more enclosed of the two, yet it is the less saline. Option D is wrong because the Arabian Sea receives less rainfall, and rain lowers salinity instead of raising it. Exam tip: evaporation raises salinity; river water and rainfall lower it.

The correct answer is A, a destination-based consumption tax. Goods and Services Tax is collected by the state where the goods or services are finally consumed, not by the state that produced them. It came into force on 1 July 2017 through the Constitution (101st Amendment) Act, 2016, and replaced a thicket of central and state taxes such as excise duty, service tax, VAT and octroi. It is a multi-stage value-added tax: a seller pays tax on the full value but claims input tax credit for the tax already paid on purchases, so only the value added at each stage is really taxed. Rates are decided by the GST Council under Article 279A, chaired by the Union Finance Minister. Option B is wrong because GST is not levied at the point of production; the earlier regime taxed at origin. Option C is wrong because GST is not a plain sales tax on each transaction, since input credit runs through the chain. Option D is wrong on both counts, origin and sales transaction. Exam tip: GST — destination-based, multi-stage, value-added; 101st Amendment, 1 July 2017.

The correct answer is D, New Delhi. The National Green Tribunal was set up by the National Green Tribunal Act, 2010, and started work on 18 October 2010 with its principal bench at New Delhi. Its four zonal benches sit at Bhopal, Pune, Kolkata and Chennai, and it also holds circuit sittings at other places. India thus became one of the first countries to create a dedicated court for environmental disputes, and the tribunal is required to decide cases within six months of filing. It hears matters under laws such as the Water Act, the Air Act and the Environment (Protection) Act, is headed by a chairperson who has been a judge of the Supreme Court or a High Court Chief Justice, and its orders can be appealed only in the Supreme Court. Option A is wrong because Kolkata holds the eastern zone bench, not the principal seat. Option B is wrong because Hyderabad has no bench of the tribunal. Option C is wrong because Lucknow is not the principal seat either. Exam tip: NGT Act 2010 — principal bench Delhi; zonal benches Bhopal, Pune, Kolkata and Chennai.

The correct answer is A, temperature is highest at ground level and decreases with increasing altitude. In the troposphere the air is warmed mainly from below: the earth absorbs incoming short-wave insolation and then heats the layer of air touching it by conduction, radiation and convection. So the farther you go from this heat source, the colder the air, and the normal lapse rate is about 6.5 degrees Celsius for every 1,000 metres of ascent. This is why hill stations are cool in summer and high peaks stay under snow even in the tropics. Option B is wrong because that upside-down pattern is a temperature inversion, a local and short-lived reversal seen in valleys on calm clear winter nights, not the normal rate. Option C is wrong because temperature does not stay steady with height; the troposphere cools steadily upward. Option D is wrong because no such initial warming occurs in the normal profile. Exam tip: normal lapse rate is a fall of about 6.5 degrees Celsius per kilometre; the opposite is called an inversion.

The correct answer is D, Neon. When electricity is passed through a sealed tube holding neon at low pressure, the gas atoms are excited and give out a bright orange-red glow, which is why advertising signs are still called neon signs. Neon is a noble gas discovered in 1898 by Ramsay and Travers; it is chemically inert, forms no ordinary compounds, and is also used in voltage testers, high-voltage indicators and lightning arresters. Every gas glows in its own colour in a discharge tube, and that colour is the fingerprint of its atomic energy levels. Option A is wrong because helium gives a pale pinkish-white glow and is better known for filling balloons and airships. Option B is wrong because argon glows a pale violet-blue and is used to fill electric bulbs and to shield welding. Option C is wrong because nitrogen glows bluish, and its common uses are as an inert packing gas and as a liquid coolant. Exam tip: neon gives red light in a discharge tube, while argon is the gas that fills ordinary electric bulbs.

The correct answer is B, Qila-i-Kuhna Masjid. This mosque stands inside the Purana Qila in Delhi and was built by Sher Shah Suri around 1541, during the Sur interregnum that interrupted Mughal rule, so it belongs to a period before Shah Jahan was born. Its five arched bays in red sandstone with marble inlay are counted among the finest pre-Mughal mosques of Delhi. Shah Jahan, who ruled from 1628 to 1658, is the great builder of the dynasty: he raised Shahjahanabad with its Red Fort, the Taj Mahal at Agra and the Peacock Throne. Option A is wrong because the Moti Masjid, the pearl mosque in white marble, was built in the Agra Fort in his reign. Option C is wrong because the Jama Masjid of Delhi, the largest mosque in India, was completed under him in 1656. Option D is wrong because the Rang Mahal is one of the painted palaces of his Red Fort. Exam tip: Purana Qila and its Qila-i-Kuhna Masjid belong to Sher Shah Suri, not the Mughals.

The correct answer is A, whatever the change in price, there is absolutely no change in demand. Price elasticity of demand is the percentage change in quantity demanded divided by the percentage change in price. If the elasticity is zero, the numerator is zero: buyers take the same quantity however the price moves. This case is called perfectly inelastic demand and its demand curve is a vertical straight line. Textbooks illustrate it with a life-saving medicine or with salt, goods a household buys in a fixed quantity because there is no substitute and the spending is small. Option B is wrong because a small response to a small price change means elasticity between zero and one, that is inelastic but not zero demand. Option C is wrong because a large response to a small price change is elastic demand, with elasticity greater than one. Option D is wrong because that too describes ordinary inelastic demand, where some change still takes place. Exam tip: elasticity zero is a vertical curve, elasticity infinity a horizontal one, and elasticity one is unitary.

The correct answer is D, Nitrogen. Nitrogen makes up about 78 per cent of the atmosphere, yet it is not a greenhouse gas. A molecule traps heat only if it can absorb outgoing infrared radiation, and that needs vibrations which change the spread of electric charge in the molecule. Nitrogen is a simple molecule of two identical atoms, so it is transparent to infrared; the same is true of oxygen. The gases that do trap heat are water vapour, carbon dioxide, methane, nitrous oxide, ozone and the halocarbons, and together they keep the earth about 33 degrees Celsius warmer than it would otherwise be. Option A is wrong because water vapour is the most abundant greenhouse gas of all. Option B is wrong because chlorofluorocarbons are powerful greenhouse gases that also destroy the ozone layer, which is why the Montreal Protocol phases them out. Option C is wrong because methane traps far more heat per molecule than carbon dioxide. Exam tip: nitrogen and oxygen are not greenhouse gases, though they make up most of the air.

The correct answer is B, inter cropping. In intercropping two or more crops are grown together on the same field at the same time, but sown in a definite pattern of rows, such as a few rows of soyabean between rows of maize, or bajra with lobia. The crops chosen have different nutrient needs and different rooting depths, so they use the soil, sunlight and water better, pests spread more slowly, and if one crop fails the farmer still has the other. It differs from mixed cropping, where the seeds of two crops are simply mixed and broadcast with no row pattern. Option A is wrong because crop rotation means growing different crops one after another on the same field in successive seasons, to restore fertility. Option C is wrong because alternate cropping is not the name for sowing two crops side by side in the same season. Option D is wrong because kharif names a season, the monsoon crop sown in June and July, not a method of cropping. Exam tip: mixed cropping has no rows, intercropping has definite rows, rotation is one crop after another.

The correct answer is B, Separate Electorate. The Nehru Report of August 1928 was the draft constitution prepared by a committee of the All Parties Conference under Motilal Nehru, with Tej Bahadur Sapru, Subhas Chandra Bose and others, as Indians’ answer to Lord Birkenhead’s taunt that they could not agree on a constitution of their own. The report firmly rejected separate electorates, the device introduced by the Morley-Minto reforms of 1909, and asked instead for joint electorates with seats reserved for minorities where they were in a minority. Option A is wrong because dominion status was its central demand, which is exactly why the younger leaders who wanted complete independence objected. Option C is wrong because the report did favour a unitary and democratic centre with responsible government. Option D is wrong because adult suffrage, along with a list of fundamental rights, was one of its clear recommendations. Jinnah replied to it with his Fourteen Points in 1929. Exam tip: Nehru Report 1928 — dominion status, joint electorates, adult suffrage, fundamental rights.