Current Affairs 4 October 2026: Today's GK & MCQs

The correct answer is B, Quasi - Judicial Procedure. Parliament frames a charge, takes evidence and gives the President a hearing, so the two Houses act like a court even though they are law-making bodies. Article 61 lays down the process, and the only ground is violation of the Constitution. The charge may start in either House, needs a notice signed by one-fourth of that House's members given 14 days in advance, and must then be passed by a majority of two-thirds of the total membership of that House. The other House investigates the charge, and the President has the right to appear and be represented. The President stands removed only when the second House also passes the resolution by the same two-thirds majority. A is wrong because no court tries the President. C is wrong because the Houses go beyond law-making here and weigh evidence. D is wrong because the executive has no role in it. Exam tip: Article 61, violation of the Constitution, two-thirds of total membership of each House.

The correct answer is D, 243 (G). Article 243G allows a state legislature to endow Panchayats with the powers and authority they need to work as institutions of self-government. Part IX of the Constitution, which holds Articles 243 to 243-O, was inserted by the 73rd Constitutional Amendment Act of 1992 and came into force on 24 April 1993. Under Article 243G a state may give Panchayats the duty to prepare plans, to carry out schemes and to handle the subjects listed in the Eleventh Schedule, which names 29 items such as agriculture, drinking water, rural roads and primary education. A is wrong because Article 243A deals with the Gram Sabha, the village assembly of registered voters. B is wrong because there is no such Article; Article 356 covers President's rule in a state. C is wrong because Article 357 concerns the exercise of legislative powers during President's rule. Exam tip: 243A Gram Sabha, 243B constitution of Panchayats, 243G powers, Eleventh Schedule 29 subjects.

The correct answer is B, Tej Bahadur Sapru. The Liberal leader Tej Bahadur Sapru, working with M. R. Jayakar, brought Gandhi and Viceroy Lord Irwin to the table and is remembered as the mediator of the pact. The agreement was signed in Delhi on 5 March 1931 and is also called the Delhi Pact. Gandhi agreed to suspend the Civil Disobedience Movement and to attend the Second Round Table Conference in London, while the government agreed to release political prisoners not convicted of violence, to return confiscated property and to allow people on the coast to make salt for their own use. A is wrong because Motilal Nehru had died in February 1931, before the pact. C is wrong because Annie Besant led the Home Rule movement and had no part in it. D is wrong because C. Y. Chintamani was a Liberal editor and politician, not the mediator here. Exam tip: Gandhi-Irwin Pact, 5 March 1931, Delhi Pact, just before the Second Round Table Conference.

The correct answer is D, Bhulabhai Desai. Bhulabhai Desai led the defence at the Red Fort trials of the Indian National Army officers, and his argument that the soldiers of a recognised army were fighting for their country's freedom turned the trials into a public cause. The first trial, held from November 1945, was of Shah Nawaz Khan, Prem Kumar Sahgal and Gurbaksh Singh Dhillon, charged with waging war against the King. The Congress set up an INA Defence Committee whose members included Jawaharlal Nehru, Tej Bahadur Sapru, Asaf Ali and Kailash Nath Katju. The men were convicted but the sentences were remitted after countrywide protests. A is wrong because Sardar Patel organised relief and funds, and did not appear in court. B is wrong because Aruna Asaf Ali was a leader of the 1942 movement, not a lawyer in the case. C is wrong because K. M. Munshi, though a lawyer, is remembered for his work in the Constituent Assembly. Exam tip: Red Fort trials 1945-46, defence led by Bhulabhai Desai.

The correct answer is A, June 3, 1947. Lord Mountbatten, the last Viceroy, announced his partition plan on 3 June 1947, which is why it is also called the June Third Plan. It offered the provinces a choice: British India would be divided into India and Pakistan, both as Dominions, the legislatures of Bengal and Punjab would vote on splitting those provinces, a referendum would be held in the North-West Frontier Province and Sylhet, and the princely states were left free to join either Dominion. The plan was given legal shape by the Indian Independence Act, passed on 18 July 1947. B is wrong because the All India Congress Committee accepted the plan on 14 June 1947, which was not the date of its announcement. C is wrong because no such announcement was made on that date. D is wrong because 20 February 1947 is Prime Minister Attlee's statement that Britain would leave India by June 1948. Exam tip: 20 Feb 1947 Attlee statement, 3 June 1947 Mountbatten Plan, 18 July 1947 Indian Independence Act.

The correct answer is B, Belgrade. The first summit of the Non-Aligned Movement met at Belgrade, then the capital of Yugoslavia, in September 1961, and twenty-five countries took part. The movement grew out of the wish of newly free nations to stay out of the two Cold War blocs, and its founders were Jawaharlal Nehru of India, Josip Broz Tito of Yugoslavia, Gamal Abdel Nasser of Egypt, Sukarno of Indonesia and Kwame Nkrumah of Ghana. Its guiding ideas were peaceful coexistence, an end to colonialism and disarmament. A is wrong because Bandung in Indonesia hosted the Afro-Asian Conference of 1955, which prepared the ground but was not a NAM summit. C is wrong because Cairo hosted the second summit in 1964. D is wrong because Jakarta hosted the tenth summit, in 1992. Exam tip: remember the order, Bandung 1955 then the first NAM summit at Belgrade in 1961.

The correct answer is C, Saint Petersburg. Bloody Sunday took place in Saint Petersburg, then the capital of Russia, on 22 January 1905, when troops fired on a peaceful procession of workers. The marchers, led by the priest Father Gapon, were carrying a petition to Tsar Nicholas II at the Winter Palace asking for an eight-hour day, better wages and an elected assembly. Hundreds were killed or wounded, the people's faith in the Tsar collapsed, and strikes and mutinies spread into what is called the Revolution of 1905. The Tsar had to issue the October Manifesto promising a Duma. A is wrong because Georgia was a province of the empire and not the site of the firing. B is wrong because Moscow became the capital only in 1918. D is wrong because Paris belongs to the French Revolution of 1789, not to this event. Exam tip: Bloody Sunday, 1905, Saint Petersburg, Father Gapon and Tsar Nicholas II.

The correct answer is B, American independence was declared. On 4 July 1776 the Second Continental Congress, meeting at Philadelphia, adopted the Declaration of Independence, by which thirteen colonies broke away from British rule. The Declaration was drafted mainly by Thomas Jefferson and set out the idea that all men are created equal and that governments draw their authority from the consent of the governed. The day is kept every year as Independence Day in the United States, though the war went on until the British surrender at Yorktown in 1781 and the Treaty of Paris of 1783. A is wrong because George Washington became the first President in 1789. C is wrong because the French alliance was signed in 1778, after the victory at Saratoga. D is wrong because slavery ended in 1865 with the Thirteenth Amendment. Exam tip: fix the sequence, 1776 Declaration, 1781 Yorktown, 1783 Treaty of Paris.

The correct answer is B, Gurjar-Pratihara. Both temples belong to the Gurjara-Pratihara style, the western Indian form of the Nagara tradition that grew under Pratihara rule between the eighth and the eleventh centuries. The Someshwar temple at Kiradu in Barmer district is the finest of a group of five temples, so richly carved that Kiradu is called the Khajuraho of Rajasthan. The Harshat Mata temple at Abhaneri in Dausa district stands on a high platform beside the famous Chand Baori stepwell and shows the same curved shikhara, carved pillars and sculptured panels. A is wrong because Gupta temples, like the Dashavatara temple at Deogarh, are earlier and plainer. C is wrong because Mauryan work survives as pillars, stupas and rock-cut caves, not temples. D is wrong because the Dravida style of the south has a pyramidal vimana and a gopuram. Exam tip: Kiradu in Barmer and Abhaneri in Dausa, both Gurjara-Pratihara, Nagara family.

The correct answer is D, Rose. The Pushkar valley in Ajmer district is the rose belt of Rajasthan, and its desi gulab is grown on a large scale for processing rather than for cut flowers. The petals go into gulab jal, gulkand, rose oil and perfume, and small units around Pushkar and Ajmer buy the crop, which is why the area is often called the flower garden of Rajasthan. The town itself is known for the Brahma temple and for the cattle fair held at Kartik Purnima. A is wrong because tomato is a common vegetable crop with no special link to Pushkar. B is wrong because date palm in Rajasthan is associated with the dry districts of Jaisalmer, Bikaner and Barmer. C is wrong because chrysanthemum is grown mainly in the south and in hill areas for cut flowers. Exam tip: Pushkar means roses, so remember the pair Pushkar and gulab jal or gulkand.

The correct answer is B, Europe, Antarctica, South America, North America. Smallest to largest, Europe covers about 10.2 million square kilometres, Antarctica about 14 million, South America about 17.8 million and North America about 24.7 million. The full order of the seven continents from largest to smallest is Asia, Africa, North America, South America, Antarctica, Europe and Australia, and Asia alone takes up about thirty per cent of the land surface. Europe is often called a peninsula of the Eurasian landmass because it is not separated from Asia by sea, while Antarctica, though larger than Europe, is almost wholly covered by ice and has no permanent population. A is wrong because it places Antarctica first, though it is bigger than Europe. C is wrong because it makes Antarctica the largest of the four. D is wrong because South America is bigger than both Europe and Antarctica. Exam tip: learn one chain, Asia, Africa, North America, South America, Antarctica, Europe, Australia.

The correct answer is D, Western disturbances. Mawat is the local name in Rajasthan and the neighbouring plains for the light winter rain brought by western disturbances. These are low pressure systems that form over the Mediterranean region, travel east with the subtropical westerly jet stream and reach north-west India between December and February. The rain is small in amount but comes at the right time for the rabi crop, so wheat, gram, barley and mustard gain from it and farmers treat Mawat as golden drops. The same systems give snow to the western Himalayas. A is wrong because the retreating north-east monsoon brings winter rain to the Tamil Nadu coast, not to Rajasthan. B is wrong because the south-west monsoon is the rain of June to September. C is wrong because India has no south-east monsoon. Exam tip: Mawat equals winter rain from western disturbances, a boon for the rabi crop.

The correct answer is C, Between 40 degrees S and 50 degrees S latitudes. The Roaring Forties are the strong westerly winds of the southern hemisphere between about 40 and 50 degrees south. They blow with such force because there is almost no land in that belt to slow them down, so sailing ships once used them on the route to Australia. Further south the same westerlies are called the Furious Fifties, between 50 and 60 degrees, and the Shrieking or Screaming Sixties beyond 60 degrees. A is wrong because that belt holds the south-east trade winds and the subtropical high. B is wrong because the matching northern latitudes have large landmasses, so the winds there are weaker and are not given this name. D is wrong because the equatorial belt is the doldrums, a zone of calm and rising air. Exam tip: Roaring Forties 40-50 S, Furious Fifties 50-60 S, Shrieking Sixties beyond 60 S.

The correct answer is C, 949, 929. Census 2011 put the rural sex ratio at 949 females per thousand males and the urban sex ratio at 929, while the figure for the country as a whole was 943, the highest since 1951. The sex ratio is lower in towns and cities mainly because men move there for work and leave their families behind in the village. Two other numbers from the same census are worth fixing: the child sex ratio in the age group 0 to 6 years fell to 919, the lowest since independence, and Kerala had the best state ratio at 1084 while Haryana had the lowest at 879. A, B and D are wrong because they misstate both halves of the pair; no census has recorded a rural figure of 969, 959 or 939 with the urban figure shown against it. Exam tip: Census 2011 sex ratio, total 943, rural 949, urban 929, child 919.

The correct answer is A, Tube well. Tube wells irrigate the largest share of the net irrigated area of Rajasthan, and groundwater drawn through tube wells and wells together waters the greater part of the state's fields. The reason is the climate: rainfall is low and uncertain over most of the state and perennial rivers are few, so a farmer who wants a second crop has to pump water. This heavy drawing of groundwater has pushed many blocks of Rajasthan into the over-exploited category, which is why drip and sprinkler irrigation are pressed in the state. B is wrong because ponds and tanks serve only small pockets, mostly in the south and south-east. C is wrong because open wells, once the mainstay, now water a much smaller area than tube wells. D is wrong because canals, led by the Indira Gandhi Canal, come second and are limited to the north-west and the Chambal command. Exam tip: in Rajasthan groundwater leads, tube wells first and canals second.

The correct answer is D, Kanwar Sain. The engineer Kanwar Sain conceived the plan in 1948 of carrying the surplus water of the Sutlej and the Beas into the Thar desert, and the canal was taken up on his design. Work began on 31 March 1958 on what was then called the Rajasthan Canal, which draws water from the Harike barrage below the meeting of the Sutlej and the Beas in Punjab. It was renamed the Indira Gandhi Canal in 1984 and, with its branches, is the longest irrigation canal in India, turning parts of Sriganganagar, Hanumangarh, Bikaner and Jaisalmer into cropland. A is wrong because Mohanlal Sukhadia was a Chief Minister of Rajasthan in whose years the work went ahead. B is wrong because Jawaharlal Nehru was the Prime Minister of the day, not the author of the plan. C is wrong because Jainarayan Vyas was also a Chief Minister. Exam tip: conceived by Kanwar Sain in 1948, work started 1958, renamed 1984.

The correct answer is D, Shriganganagar - Hanumangarh. Sem is the local word for waterlogging with salt, and it hurts Sriganganagar and Hanumangarh the most because these districts lie in the command area of the Gang Canal and the Indira Gandhi Canal. Years of canal water spread by flood irrigation, without drains and over a hard layer below the soil, have raised the water table until it reaches the root zone. As the water stands and evaporates it leaves salt behind, white patches appear on the surface and yields fall. Lined channels, surface and sub-surface drains, sprinkler irrigation and the planting of eucalyptus are used against it. A is wrong because Bharatpur and Dhaulpur face flooding of a different kind in the eastern plain. B is wrong because Banswara and Dungarpur are hilly, high-rainfall tribal districts. C is wrong because Jalore and Sirohi face salinity of groundwater and drought. Exam tip: sem means canal-fed waterlogging, remember the Indira Gandhi Canal command.

The correct answer is C, Gross investment - Depreciation. Net investment is gross investment minus depreciation, that is, the addition to the stock of capital left after making good the wear and tear of existing machines, buildings and equipment. Gross investment is the whole spending on capital goods in a year, while depreciation, also called consumption of fixed capital, is the fall in the value of capital through normal use and age. The same subtraction turns gross figures into net figures elsewhere in national accounts: gross domestic product minus depreciation gives net domestic product. If net investment is positive the economy's capital stock is growing, and if it is negative the stock is shrinking. A and B are wrong because sudden destruction of capital by accident or by a flood or earthquake is a capital loss and is not counted as depreciation. D is wrong because only one of the three statements is correct. Exam tip: net equals gross minus depreciation, the same rule for investment, GDP and national product.

The correct answer is D, Price Index. A price index measures how the price of a commodity or of a basket of goods has moved between a base period and the current period, so the price of wheat over the years is read from a price index. The base year is given the value 100 and every later price is shown against it, which makes a long series comparable even when the rupee's value changes. In India the Wholesale Price Index and the Consumer Price Index are the best known price indices, and Laspeyres' formula uses base year quantities as weights while Paasche's formula uses current year quantities. A is wrong because a volume or quantity index tracks how much is produced or sold, not the price. B is wrong because an aggregate index is a way of building an index from several items and is not meant for one commodity's price. C is wrong because neither of those two answers fits. Exam tip: price index for prices, quantity index for output, value index for the two together.

The correct answer is B, Earthworm. The earthworm is called the farmer's friend because its work keeps soil fit for crops. As it burrows it loosens the soil and lets air and water reach the roots, and the castings it leaves behind are rich in nitrogen, phosphorus and potash, so the topsoil is steadily renewed. Charles Darwin called earthworms nature's ploughmen for this reason. Farmers use the same habit in vermicomposting, where species such as Eisenia fetida turn cattle dung and crop waste into fine manure within a few weeks. A is wrong because the cockroach is a household pest that spoils food and carries germs. C is wrong because the honey bee is useful as a pollinator and for honey, but the name friend of the farmer is not given to it. D is wrong because the housefly spreads diseases such as typhoid and cholera. Exam tip: earthworm, the farmer's friend and nature's plough, used in vermicompost.

The correct answer is B, The rate of the forward and reverse reactions. Chemical equilibrium is a dynamic state: both reactions go on, but at the same speed, so no net change is seen. Because the two rates are equal, the amounts of reactants and products stay fixed, pressure and colour stop changing, and the reaction looks finished although molecules keep reacting on both sides. The equilibrium constant is the ratio of the two rate constants, K equals k forward divided by k reverse, and a catalyst speeds up both sides alike, so it brings equilibrium sooner without shifting it. A is wrong because the concentrations become constant, not equal; they are usually quite different and depend on the value of K. C is wrong because the two rate constants are equal only in the special case where K equals one. D is wrong because statement C does not hold in general. Exam tip: at equilibrium rates are equal and concentrations are constant, and K equals k forward over k reverse.

The correct answer is B, Suspension. A suspension is a heterogeneous mixture because the particles of the solute are large enough to be seen, they do not dissolve, they settle when the mixture is left standing and they can be separated by filtering. Chalk powder stirred into water, muddy water and lime water are everyday examples, and such a mixture scatters a beam of light because the particles are bigger than about one thousand nanometres. A solution, in contrast, is homogeneous: sugar in water or salt in water gives one uniform phase, the particles cannot be seen, nothing settles and filter paper does not hold them back. A colloid, such as milk or fog, lies between the two and is also heterogeneous, though it does not settle. A is wrong because a solution is homogeneous. C is wrong because it wrongly includes the solution. D is wrong because a suspension certainly is heterogeneous. Exam tip: solution homogeneous, colloid and suspension heterogeneous; only the suspension settles.

The correct answer is C, poisons. A catalytic poison is a substance that lowers or destroys the activity of a catalyst, usually because it sticks firmly to the active surface and leaves no room for the reactants. Carbon monoxide and sulphur compounds poison platinum and nickel catalysts, which is why petrol for vehicles with a catalytic converter must be low in sulphur, and arsenic compounds poison the iron catalyst used in making ammonia. Such poisoning is often irreversible, so industrial gases are cleaned before they reach the catalyst bed. A is wrong because controller is not a term used in catalysis. B is wrong because a promoter does the opposite and raises the activity of a catalyst, as molybdenum does for iron in the Haber process. D is wrong because an initiator starts a chain reaction, for example in polymerisation, and is used up in it. Exam tip: promoter raises, poison lowers; molybdenum promotes iron in the Haber process.

The correct answer is C, Bakelite. Bakelite is a thermosetting polymer, made by condensing phenol with formaldehyde, and once it has set under heat its chains are cross-linked, so it cannot be melted and moulded again. That hardness and poor conduction of heat and electricity are why bakelite is used for switches, plugs, handles of pans and radio cabinets; it was prepared by Leo Baekeland and was the first fully synthetic plastic. Melamine and urea-formaldehyde resins behave in the same way. A is wrong because polythene is a thermoplastic that softens on heating and can be recycled into new articles. B is wrong because PVC is also a thermoplastic, used for pipes, cable covers and raincoats. D is wrong because neoprene is a synthetic rubber, that is an elastomer, valued for resisting oil and petrol. Exam tip: thermosetting means bakelite, melamine and urea-formaldehyde; thermoplastic means polythene, PVC and polystyrene.

The correct answer is A, Goat. Capra hircus is the scientific name of the domestic goat, in which Capra is the genus and hircus the species, written in the two-word form that Carl Linnaeus gave to biology. The goat is a ruminant of the family Bovidae and is called the poor man's cow because it gives milk and meat on little feed and thrives in dry country; Rajasthan leads the states in goat population and Sirohi, Marwari, Jakhrana and Barbari are among its known breeds. B is wrong because cattle are Bos indicus, the humped Indian cattle, or Bos taurus. C is wrong because the sheep is Ovis aries. D is wrong because the Indian water buffalo is Bubalus bubalis, the animal that gives most of India's milk. Exam tip: fix the four names together, goat Capra hircus, sheep Ovis aries, cattle Bos indicus and buffalo Bubalus bubalis.

The correct answer is A, Ranikhet. Newcastle disease is called Ranikhet disease in India because the first serious outbreak in the country was reported from Ranikhet in the Kumaon hills, while the name Newcastle comes from Newcastle upon Tyne in England, where it was identified in 1926. It is caused by a paramyxovirus, spreads fast through a flock by droppings and droplets, and shows itself as gasping, greenish diarrhoea, twisted neck and a sharp fall in egg laying, so losses can be heavy. There is no cure, and poultry keepers rely on vaccination with the F and R2B strains along with strict hygiene. B is wrong because IBD, infectious bursal disease or Gumboro, attacks the bursa and the young bird's immunity. C is wrong because coccidiosis is caused by Eimeria, a protozoan, and brings bloody droppings. D is wrong because fowl pox is a different viral disease, marked by warty scabs on the comb and wattles. Exam tip: Ranikhet equals Newcastle disease, a viral disease met by vaccination.

The correct answer is C, Water Conservation. Tarun Bharat Sangh works on water conservation, and its base is at Bhikampura in Alwar district of Rajasthan. Led by Rajendra Singh, known as the waterman of India, villagers of the area built and repaired thousands of johads, the traditional earthen check dams that hold rainwater and let it sink into the ground. Wells filled again, fields came back under crops and streams such as the Arvari, dry for years, began to flow, which is why the body is studied as a model of community-led water harvesting. Rajendra Singh received the Ramon Magsaysay Award in 2001 and the Stockholm Water Prize in 2015. A is wrong because women's groups are part of the work but not its field. B is wrong because fighting corruption is not its subject. D is wrong because it is not a tribal youth organisation, and Alwar is not a tribal belt. Exam tip: Tarun Bharat Sangh, Rajendra Singh, johads of Alwar and the revived Arvari river.

The correct answer is D, http. In a web address the part before the colon and the two slashes names the protocol, so http, the HyperText Transfer Protocol, is the set of rules by which a browser asks a server for a page and the server answers. A full address has four parts: the protocol, the host name, the domain name with its suffix, and the path of the file; in https the letter s stands for secure, because the traffic is encrypted with SSL or TLS. A is wrong because .co marks a commercial entity and is part of the domain name. B is wrong because .in is the country code top level domain for India. C is wrong because www is the host or subdomain name of the web server, not a protocol. Exam tip: read a URL as protocol, then host, then domain, then path, and remember that https is http with SSL or TLS.

The correct answer is B, Web Resource that specifies its location on a computer network and a mechanism for retrieving it. A URL is the address of a web resource: it says where the resource sits on the network and, through the scheme written in front, how it is to be fetched. Thus it carries the protocol, the host name, the port if one is needed, and the path of the file, and schemes such as http, https, ftp and mailto each bring their own way of retrieving. The idea was given by Tim Berners-Lee along with HTML and HTTP, and a URL is one kind of Uniform Resource Identifier. A is wrong because it is too loose; a URL does not address every computer resource, such as a file on a local disk. C is wrong because a printer is reached through a print queue or an IP address, not by a URL. D is wrong because a storage server is only one of the many things a URL may point to. Exam tip: a URL answers two questions, where the resource is and how to fetch it.

The correct answer is B, 90 degrees. When the ray makes 90 degrees with the surface it is travelling along the normal, so the angle of incidence measured from the normal is zero and the ray goes straight on without bending. Refraction is the bending of light as its speed changes on entering a new medium, and by Snell's law the sine of the angle of incidence divided by the sine of the angle of refraction equals the refractive index; with an angle of incidence of zero both sines are zero and no bending is possible, though the speed and the wavelength still change. A is wrong because 120 degrees to the surface means the ray strikes at a slant and bends. C is wrong because at 45 degrees to the surface the angle of incidence is also 45 degrees, so the ray refracts. D is wrong because 0 degrees means the ray grazes along the surface and does not enter medium Y. Exam tip: along the normal means no bending; bending grows as the ray slants more.

The correct answer is A, Chalukya. Vikramaditya VI ruled the Western Chalukya kingdom of Kalyani, and his court poet Bilhana wrote the Vikramankadevacharita on his life. Vikramaditya VI reigned from about 1076 to 1126 CE from Kalyani in present-day Karnataka, and he started the Chalukya-Vikrama era, a new reckoning counted from his accession, which very few Indian rulers ever did. Another scholar of his court was Vijnaneshwara, who wrote the Mitakshara, the best known commentary on the Yajnavalkya Smriti and a key text of Hindu law. B is wrong because the Pallavas ruled from Kanchi and had faded away by the tenth century. C is wrong because the Rashtrakutas of Manyakheta were displaced by these very Chalukyas in 973 CE. D is wrong because the Western Gangas ruled Talakad in southern Karnataka and are remembered for Shravanabelagola, not for Bilhana. Exam tip: Bilhana wrote Vikramankadevacharita for Vikramaditya VI, and Vijnaneshwara wrote the Mitakshara at the same court.

The correct answer is B, Nitrogen. An ordinary incandescent bulb is filled with an unreactive gas, nitrogen usually mixed with argon, so that the white-hot tungsten filament does not burn away. The filament works at about 2500 degrees Celsius, and in air the tungsten would oxidise within seconds. Nitrogen and argon do not react with tungsten, and the gas pressure inside also slows the evaporation of the metal, so the filament lasts longer and the glass does not blacken quickly. A is wrong because halogens such as iodine and bromine are added only in halogen lamps, a special high-temperature type, not in the common bulb. C is wrong because carbon dioxide would release oxygen at that temperature and attack the filament. D is wrong because hydrogen is highly inflammable and would make the bulb dangerous. Exam tip: filament is tungsten, melting point about 3400 degrees Celsius, and the bulb is filled with nitrogen and argon.

The correct answer is D, Bali Trutiya. Bali Trutiya, also written Bali Tritiya, is an Odia festival kept mainly by married women of Odisha in the month of Bhadrab. The women fast through the day, shape a small heap or image out of sand and earth, and worship Shiva and Parvati with it, praying for the long life of their husbands and the well-being of the family. The name comes from bali, the Odia word for sand, which is why the vrat is also called the sand festival. A is wrong because the Hornbill Festival is Nagaland’s ten-day tribal festival held at Kisama near Kohima every December. B is wrong because Chappar Mela is a fair of Himachal Pradesh, not of Odisha. C is wrong because Bonalu is a Telangana festival in which Mahakali is worshipped at Hyderabad and Secunderabad during Ashada. Exam tip: Hornbill belongs to Nagaland, Bonalu to Telangana and Bali Trutiya to Odisha.

The correct answer is C, Zil-Ilahi (Shadow of God). Balban took the title Zil-i-Ilahi to claim that the sultan rules as the shadow of God on earth, a claim that placed him far above his nobles. He had been the real power behind Sultan Nasiruddin Mahmud before taking the throne himself, and he was the strongest ruler of the Ilbari or so-called Slave dynasty. He broke the hold of the Chahalgani, the group of forty Turkish nobles, brought in the Persian court customs of sijda, prostration before the sultan, and paibos, kissing his feet, and kept a separate network of spies. He also organised the military department, the diwan-i-arz. A is wrong because Nur-al-Din was never his title. B is wrong because Nur Mahal was a title of Nur Jahan, the queen of Jahangir. D is wrong because Jahan Panah is linked with Muhammad bin Tughlaq, who built a city of that name at Delhi. Exam tip: Balban stands for Zil-i-Ilahi, sijda and paibos, and the diwan-i-arz.

The correct answer is B, Mandal Commission. The Second Backward Classes Commission, headed by B. P. Mandal, recommended 27 per cent reservation for Other Backward Classes in central government services and public undertakings. It was appointed in 1979 and submitted its report in 1980, listed 3,743 castes as backward and put the share of the OBCs in the population at about 52 per cent. The quota was fixed at 27 per cent so that total reservation would stay within the 50 per cent ceiling the courts had indicated. The recommendation was put into effect in 1990, and the Supreme Court upheld it in the Indra Sawhney case of 1992. A is wrong because the Sarkaria Commission of 1983 examined Centre-State relations. C is wrong because the Balwant Rai Mehta Committee of 1957 suggested the three-tier panchayati raj system. D is wrong because the Kothari Commission of 1964-66 dealt with education. Exam tip: Mandal Commission 1979, report 1980, 27 per cent OBC quota, upheld in Indra Sawhney 1992.

The correct answer is D, 1916. The Home Rule Movement began in 1916, when two leagues were set up to demand self-government for India within the British Empire. Bal Gangadhar Tilak started the Indian Home Rule League at Belgaum in April 1916, and Annie Besant founded her Home Rule League at Madras in September 1916. The movement borrowed its name and method from the Irish Home Rule campaign and carried the demand for swaraj to students, traders and professionals at a time when the Congress was quiet after the split of 1907. Its pressure helped bring about the Montagu Declaration of 1917 and the Lucknow Pact between the Congress and the Muslim League. A is wrong because 1914 is the year the First World War broke out. B is wrong because 1915 is the year Gandhi returned from South Africa. C is wrong because 1917 saw the Champaran satyagraha, which came after the leagues were formed. Exam tip: Tilak April 1916 at Belgaum, Annie Besant September 1916 at Madras.

The correct answer is A, France. France has twelve time zones, more than any other country, because its overseas departments and territories are scattered across the Pacific, the Indian Ocean, the Atlantic and the Caribbean. Mainland France keeps one zone, and places such as French Polynesia, New Caledonia, Reunion, Guadeloupe and French Guiana add the rest, so a single country spans almost the whole clock. Russia comes second with eleven zones, and these lie in one continuous landmass from Kaliningrad in the west to Kamchatka in the east. B is wrong because the United States has nine standard zones at home and eleven in all when its territories are counted, still short of France. C is wrong because Russia has eleven zones, one less than France. D is wrong because the United Kingdom keeps a single zone at home and does not reach France even with its overseas territories. Exam tip: France 12 zones, Russia 11, the United States 11 with territories, while India keeps one zone based on 82 degrees 30 minutes East.

The correct answer is C, Prithviraja III. Prithviraja III, the Chahamana or Chauhan ruler of Ajmer and Delhi, defeated Muhammad Ghori in the First Battle of Tarain in 1191; he is the Prithviraj Chauhan of popular memory. Tarain, now Taraori, lies near Thanesar in Haryana on the old route to Delhi, and the same ground saw the Second Battle of Tarain in 1192, in which Ghori returned, defeated Prithviraja and opened north India to Turkish rule. Chand Bardai, who wrote the Prithviraj Raso, and Jayanaka, who wrote the Prithviraja Vijaya, are linked with his court. A is wrong because Vigraharaja III ruled the Chahamanas long before Ghori appeared in India. B is wrong because Ajayaraja II is remembered for founding Ajmer in the twelfth century, not for this battle. D is wrong because Durlabharaja III also belongs to the earlier line of Ajmer rulers. Exam tip: First Tarain 1191 Prithviraja wins, Second Tarain 1192 Ghori wins.

The correct answer is C, Government of India Act, 1935. The Act of 1935 ended dyarchy in the provinces, granted provincial autonomy and placed the whole provincial administration under ministers answerable to elected legislatures. Dyarchy had been brought in by the Government of India Act of 1919, which split provincial subjects into transferred subjects run by Indian ministers and reserved subjects kept with the Governor. The 1935 Act scrapped that split, widened the franchise to about one-sixth of the adult population, provided for a federation with a bicameral central legislature, created the Federal Court, and introduced dyarchy at the Centre instead. The elections held under it in 1937 brought Congress ministries to power in most provinces. A is wrong because the Charter Act of 1793 mainly renewed the Company’s trading rights. B is wrong because the 1919 Act began dyarchy rather than ending it. D is wrong because Pitt’s India Act of 1784 set up the Board of Control in London. Exam tip: 1919 brought dyarchy to the provinces, 1935 removed it there and shifted it to the Centre.

The correct answer is A, Endogenic Forces. Mountains are built by endogenic forces, the forces that act from inside the earth and raise, bend or break the crust. They draw their energy from the earth’s internal heat and from the movement of the plates. Slow or diastrophic movements fold and lift rock over millions of years and give rise to fold mountains such as the Himalayas, the Alps and the Andes, while sudden movements appear as earthquakes and volcanic eruptions, which build volcanic mountains. Endogenic forces are therefore called constructive, because they create relief on the surface. B is wrong because exogenic forces such as running water, wind, waves and glaciers act on the surface and wear mountains down instead of raising them. C is wrong because gravity only helps loose material move downhill, as in landslides. D is wrong because the earth’s magnetic field records plate movement but does not lift land. Exam tip: endogenic forces build through diastrophism and volcanism, exogenic forces destroy through weathering and erosion.

The correct answer is B, 323 BCE. Alexander the Great died in 323 BCE at Babylon, aged about thirty-two, on his way back from the Indian campaign. He became king of Macedon in 336 BCE, overthrew the Persian empire of Darius III, and in 326 BCE crossed the Indus and fought Porus on the Jhelum in the Battle of the Hydaspes. His soldiers refused to march beyond the Beas, so he turned back along the Indus and through Baluchistan, reached Babylon and died there of fever. His empire was then divided among his generals, and Seleucus took the eastern part. A is wrong because 300 BCE falls after his death, by which time Chandragupta Maurya was already ruling Magadha. C is wrong because 423 BCE belongs to the age of the Peloponnesian War in Greece, a century before Alexander. D is wrong because 623 BCE is three centuries too early, long before Macedon rose to power. Exam tip: Alexander lived 356 to 323 BCE, invaded India in 326 BCE and died at Babylon.

The correct answer is D, Chauri - Chaura Incident. Gandhi called off the Non-Cooperation and Khilafat Movement after a crowd at Chauri Chaura in Gorakhpur district set fire to a police station on 5 February 1922, in which about twenty-two policemen died. Gandhi held that the people were not yet trained in non-violence, and the Congress Working Committee withdrew the movement at Bardoli on 12 February 1922. Many leaders, among them Motilal Nehru, C. R. Das and Subhas Chandra Bose, were unhappy with the decision, and the dispute led to the forming of the Swaraj Party in 1923. Gandhi was soon tried for sedition and sentenced to six years in the Great Trial at Ahmedabad. A is wrong because the Rowlatt Act of 1919 set off the earlier Rowlatt satyagraha. B is wrong because Tilak died in August 1920, before the movement had properly begun. C is wrong because the Jallianwala Bagh massacre of April 1919 was one of the causes of Non-Cooperation, not its end. Exam tip: Chauri Chaura 5 February 1922, movement withdrawn at Bardoli on 12 February 1922.

The correct answer is C, Kerala. Kerala shows almost no difference between day and night temperatures because it lies on the coast close to the equator, where the sea keeps the air mild and the humidity stays high. Water heats and cools far more slowly than land, so a sea breeze by day and a land breeze by night hold the temperature steady, and the heavy moisture in the air traps outgoing heat at night. This small daily range, called the diurnal range of temperature, is typical of a maritime or equatorial climate. A is wrong because Rajasthan has a desert climate, where dry air and bare sand give a very large daily range, with hot days and cold nights. B is wrong because Bihar lies inland in the northern plains and has a continental climate with sharp daily and seasonal swings. D is wrong because Punjab, far from the sea, also records hot days and cold nights, especially in winter. Exam tip: coastal and equatorial places have a small diurnal range, deserts and inland plains a large one.

The correct answer is A, Milk. Milk is an emulsion because it is tiny drops of liquid fat spread through water, and an emulsion is a colloid in which one liquid is dispersed in another liquid. The fat droplets in milk do not join together because casein, a milk protein, acts as the emulsifying agent and coats each drop. Butter, cream, mayonnaise and cold creams are other everyday emulsions; in butter and cream the arrangement is reversed, with water dispersed in fat. B is wrong because mist is tiny water drops spread in air, which makes it an aerosol and not an emulsion. C is wrong because a coloured gemstone is a solid dispersed in a solid, so it is a solid sol. D is wrong because clouds are also water drops in a gas and belong with aerosols. Exam tip: liquid in liquid is an emulsion as in milk, liquid in gas is an aerosol as in cloud and mist, and solid in liquid is a sol.

The correct answer is D, Battle of the Hydaspes. Alexander defeated Porus in 326 BCE in the Battle of the Hydaspes, fought on the banks of the Jhelum, the river the Greeks called the Hydaspes. Porus ruled the Paurava kingdom between the Jhelum and the Chenab and fought with a large force and war elephants, but Alexander crossed the swollen river upstream during the rains and struck from the flank. Greek writers say Alexander was so impressed by the courage of Porus that he gave back his kingdom and added more land to it. A is wrong because the Battle of Plassey was fought in 1757 between Robert Clive and Siraj-ud-Daulah in Bengal. B is wrong because Sakala was Alexander’s later fight against the Kathaioi tribe, not against Porus. C is wrong because the Kalinga War was fought by Ashoka in about 261 BCE. Exam tip: the Hydaspes is the Jhelum, the year is 326 BCE, and the contest was Alexander against Porus.

The correct answer is A, 1928. The All Bengal Students’ Conference was held in Calcutta in 1928 with Jawaharlal Nehru in the chair. The year was a busy one for youth politics: the Simon Commission had landed in February and was met with black flags, the All Parties Conference drew up the Nehru Report, and Nehru and Subhas Chandra Bose were drawing students, youth and workers into the national movement. Both of them also set up the Independence for India League in 1928, and at the Calcutta session of the Congress they pressed for complete independence instead of dominion status. Student bodies formed in these years later fed into the All India Students’ Federation of 1936. B is wrong because 1939 is the year of the Tripuri session and Bose’s resignation as Congress president. C is wrong because 1934 saw civil disobedience withdrawn and the Congress Socialist Party founded. D is wrong because 1920 is the year the Non-Cooperation Movement began. Exam tip: 1928 brought the Simon Commission to India, the Nehru Report, the Bardoli satyagraha and this students’ conference under Nehru.

The correct answer is D, Tundra Forest. Mosses and lichens are the typical plants of the tundra, the cold treeless belt that lies beyond the coniferous forests of the far north. The growing season there lasts only a few weeks, the subsoil stays frozen as permafrost and the soil layer is thin, so tall plants with deep roots cannot survive, while low cushions of moss and lichen along with sedges and dwarf shrubs can. Reindeer and caribou feed on lichen, which is why one kind is called reindeer moss. A is wrong because tropical rain forests are hot and wet and carry tall evergreen trees in several layers. B is wrong because temperate forests are made of broad-leaved deciduous trees such as oak, elm and maple. C is wrong because coniferous or taiga forests carry pine, fir and spruce, the softwood belt lying just south of the tundra. Exam tip: moving from the pole towards the equator the order is tundra, taiga or coniferous, temperate and then tropical.

The correct answer is B, Cm. Curium is a radioactive man-made element with the symbol Cm and atomic number 96. It was first made in 1944 at the University of California by Glenn Seaborg and his colleagues, who bombarded plutonium with helium nuclei, and it was named in honour of Marie and Pierre Curie for their work on radioactivity. Curium belongs to the actinide series of the periodic table, does not occur in nature in any useful amount, and is used as a power source in space probes and in the alpha-particle X-ray spectrometers carried by Mars rovers. A is wrong because Cr is the symbol of chromium, element number 24. C is wrong because Ci is not an element symbol at all; it stands for the curie, the older unit of radioactivity, also named after the Curies. D is wrong because Cu stands for copper, taken from its Latin name cuprum. Exam tip: Cm curium, Cr chromium, Cu copper from cuprum, and Ci the curie unit.

The correct answer is A, 1219. Genghis Khan led the Mongols into Transoxiana in 1219, the campaign that destroyed the Khwarazmian empire. The war began after the governor of Otrar killed Mongol traders and the Shah of Khwarazm, Ala-ud-din Muhammad, put Genghis Khan’s envoys to death. The Mongols then took Otrar, Bukhara and Samarkand within about two years, and the Shah fled westwards and died on an island in the Caspian. His son Jalal-ud-din was chased to the Indus in 1221 and asked Iltutmish of Delhi for shelter, which Iltutmish refused in order to keep the Mongols away from his kingdom. B is wrong because in 1208 Genghis Khan was still settling his hold over the Mongol tribes. C is wrong because 1213 belongs to his campaigns in northern China against the Jin. D is wrong because 1205 is close to the year he was proclaimed Genghis Khan, before any move westwards. Exam tip: Transoxiana 1219, Jalal-ud-din reaches the Indus in 1221, and Iltutmish refuses him shelter.

The correct answer is C, 8 August 1942. Gandhi gave the famous call of Do or Die on 8 August 1942 at the Gowalia Tank maidan in Bombay, the day the All India Congress Committee passed the Quit India resolution. The words karo ya maro told Indians to free the country or die trying, and they turned a resolution into a mass movement. The government arrested Gandhi, Nehru, Patel and the whole Congress leadership in the early hours of 9 August, so the movement was carried on without leaders by students, peasants and workers, with parallel governments set up at Ballia, Tamluk and Satara. Gandhi was held at the Aga Khan Palace in Pune, where Kasturba died in 1944. A and B are wrong because nothing of this kind happened on 14 July or 23 March 1942. D is wrong because 24 September 1942 falls well after the arrests of 9 August. Exam tip: Quit India resolution and the Do or Die call on 8 August 1942, arrests on 9 August, Gowalia Tank maidan in Bombay.