WBCS Preliminary Examination 2023 — General Studies

Answer: (A) web log

"Blog" is a clipped form of "weblog" (web + log), an online journal whose entries appear in reverse chronological order. The word "weblog" was coined by Jorn Barger in 1997, and Peter Merholz shortened it to "blog" in 1999. The other three options put the cart before the horse: "blogger" and "blogging" were formed later from "blog", and "web blog" is simply a redundancy. Similar tech coinages worth remembering: e-mail (electronic mail), modem (modulator-demodulator), pixel (picture element) and bit (binary digit).

Answer: (C) look before you leap

"Look before you leap" means think about the consequences before you act, which is exactly what reviewing one's options before deciding amounts to. "Make hay while the sun shines" means use a favourable opportunity while it lasts; "sit on the fence" means stay neutral or avoid taking sides; and "kill the golden goose" (kill the goose that lays the golden eggs) means destroy a reliable source of profit through greed. A related proverb on caution is "discretion is the better part of valour".

Answer: (A) in; up; to; for

The fixed combinations are "interested in" (+ gerund), "take up" (begin to study or practise something), "decide to" (+ verb) and "opt for" (choose), giving: She was not interested in taking up French, but decided to opt for German instead. The other three sets already fail at the first blank, since "interested to/on/for taking" is not idiomatic. Related phrasal verbs: opt out of (choose not to take part), take to (develop a liking for), take after (resemble) and take over (assume control).

Answer: (B) regicide

"Regicide" (Latin rex/regis = king + -cide = killing) is the killing of a king, or the person who does it. "Homicide" is the killing of any human being, "parricide" is the killing of a parent or near relative (patricide = father, matricide = mother) and "fratricide" is the killing of one's brother (sororicide = sister). Other "-cide" words asked in exams: infanticide (infant), uxoricide (wife), genocide (a whole people) and suicide (oneself).

Answer: (C) fit

"Fit" works in both sentences because it is both an adjective and a verb: "did not find him fit for the job" (suitable) and "was not able to fit all his belongings into one suitcase" (find room for). "Good" and "apt" can stand in only for "suitable" in sentence (i), while "cram" (to stuff in by force) can go only into sentence (ii) and even there changes the meaning. Questions of this type test homonyms, i.e. one word with two unrelated uses.

Answer: (A) Kidney diseases – urologist

Kidney diseases are treated by a nephrologist (Greek nephros = kidney). A urologist is a surgical specialist for the urinary tract (bladder, ureter, stones, prostate) and the male reproductive system, so the first pair is the mismatch. The other three pairs are correct: haematologist for blood disorders, gastroenterologist for the stomach and intestines, and oncologist for cancer. Also remember cardiologist (heart), hepatologist (liver), dermatologist (skin), neurologist (nerves), ophthalmologist (eyes) and rheumatologist (joints).

Answer: (B) Additional

An "adjunct" is something joined or added to a larger thing as a supplement rather than as an essential part (for example, an adjunct professor), so "additional" is the nearest in meaning. "Admonish" means to warn or reprimand, "amorphous" means shapeless or without clear structure, and "ambiguous" means open to more than one interpretation. Useful synonyms of adjunct are appendage, accessory, supplement and auxiliary; in grammar an adjunct is an optional adverbial that can be removed without making the sentence ungrammatical.

Answer: (C) Praise

To "chide" is to scold or rebuke someone, usually mildly, so its opposite is "praise" (also commend, applaud, laud). "Scold" and "chastise" (to reprimand or punish severely) are synonyms of chide, and "arraign" means to call someone before a court to answer a charge, or to find fault with — again closer to a synonym. Note that the booklet misprints the word "antonym" as "anonym" in this question; the intended meaning is clear from the options.

Answer: (B) Can

"Can" is a modal auxiliary: it never works as a main verb, takes no "-s" in the third person and is followed by a bare infinitive ("She can swim"). "Look" and "take" are ordinary lexical (main) verbs. "Do" is also an auxiliary when it forms questions, negatives and emphasis ("Do you know?", "I do like it"), but it can equally be a main verb ("do your homework"), and the Commission's key accepts only "Can". Auxiliaries are of two kinds: primary (be, have, do) and modal (can, could, may, might, shall, should, will, would, must, ought to), with need, dare and used to as semi-modals.

Answer: (A) Someone who specializes in statistical studies of voting patterns in elections

Psephology is the statistical study of elections, voting patterns and electoral trends; the word comes from the Greek "psephos" (pebble), because the ancient Greeks cast votes with pebbles. It was coined at Oxford in the late 1940s and popularised by election analysts such as David Butler. The other options describe a neuropsychologist, an astrophysicist and a psychoanalyst (psychoanalysis was founded by Sigmund Freud). Related terms: exit poll, opinion poll, swing, anti-incumbency and gerrymandering.

Answer: (B) My daughter said, "I prefer History over English."

Although the question says "active voice", the task is really to turn the reported statement into direct speech. Because the original verb "expressed" is in the past, the reporting verb must be "said", followed by a comma and the actual words in double quotation marks: My daughter said, "I prefer History over English." Option (A) uses the present "says" and has no comma, (C) uses "tells" with a dash, and (D) uses "told", which needs an object (told me, told us). Rule to remember: "say" can stand without a listener, but "tell" must be followed by the person addressed.

Answer: (C) not been; overseeing; giving; many

The sentence reads: He has not been meticulous in overseeing the project, giving rise to many irregularities. "Has not been" is the present perfect of "be"; a preposition ("in") must be followed by a gerund ("overseeing"); "giving rise to" is a participle phrase showing the result; and "many" goes with the countable plural "irregularities" ("much" is used with uncountable nouns). The other options break down at once: "has not being", "has not meticulous" and "has not be" are all ungrammatical.

Answer: (A) look into; more

"Look into" means to investigate or examine, and "more thoroughly" is the correct comparative adverb phrase: We need to look into this matter more thoroughly. "Look in (on)" means pay a short visit, "look up" means search for information in a reference source (or improve), and "look for" means try to find. Other frequently tested "look" phrasal verbs: look after (take care of), look down on (despise), look up to (respect), look forward to (await eagerly) and look over (examine quickly).

Answer: (A) An astrologer

A clairvoyant (French for "clear-seeing") is a person who claims to perceive things beyond the normal senses, especially future events. Among the options the nearest is an astrologer, who claims to foretell the future from the positions of stars and planets. An astronomer studies celestial bodies scientifically, an astrophysicist studies the physics of stars and galaxies, and an astronaut travels in space (cosmonaut in Russia, taikonaut in China, vyomanaut or gaganyatri in India). Related words: seer, soothsayer, oracle, palmist and fortune-teller.

Answer: (A) Only Sentence (i) is correct.

Sentence (i) is correct: "personal" is an adjective meaning private. Sentence (ii) is wrong because it needs the noun "personnel" (the staff of an organisation): "The personnel in that company are dissatisfied with their salaries." So only sentence (i) is correct. Similar confusable pairs that are regularly tested: stationary/stationery, principal/principle, complement/compliment, council/counsel, affect/effect, eminent/imminent and loose/lose.

Answer: (D) I asked him, "Why are you not in class?"

A direct question needs inverted word order (auxiliary before subject: "are you"), a comma after the reporting clause, double quotation marks and a question mark inside them: I asked him, "Why are you not in class?" Option (A) has no verb at all, while (B) and (C) keep the statement order "you are", which belongs to indirect speech. Note also the tense: "wasn't" in the reported version goes back to the present "are" in the direct question, because indirect speech had back-shifted the tense.

Answer: (B) Indirect

"Vicarious" means experienced through another person rather than at first hand (vicarious pleasure, vicarious thrill), so "indirect" is the closest word. It comes from the Latin "vicarius" (substitute), the root of "vicar" and "vice-". In law, "vicarious liability" makes an employer answerable for the acts of an employee. "Vituperative" means bitterly abusive, "supportive" means giving encouragement and "isolated" means set apart, none of which fits.

Answer: (D) Stream

PSC's key gives "Stream". A pond and a lake are both standing (lentic) water bodies, and "water body" is the general term that covers them, whereas a stream is running (lotic) water, which makes it the odd one out. An alternative line of reasoning is that "water body" is the genus and the other three are its species, but the PSC did not accept that reading. Remember the ecology terms: lentic ecosystems are still waters (ponds, lakes, wetlands) and lotic ecosystems are flowing waters (streams, rivers).

Answer: (D) counsel

"Counsel" means advice (noun) or to advise (verb), and it also denotes a barrister, so the sentence is: I am indebted to my friend's wise counsel. "Council" is an assembly or administrative body (municipal council, Legislative Council). "Councel" and "counsil" are not English words at all. A third look-alike is "consul", a diplomat who looks after a country's citizens and trade in a foreign city.

Answer: (D) pursue

The correct spelling is "pursue" (to follow, to carry on with); its noun is "pursuit". "Persue", "parsue" and "pirsue" are misspellings. Do not confuse it with "peruse" (to read carefully) or "persuade" (to convince). Other spellings that examiners like: accommodate, embarrass, occurrence, privilege, perseverance, committee, conscience and maintenance.

Answer: (C) contain

"Contain" has two senses that match the two sentences: to keep something under control or within limits (contain the crowd, contain a fire or an outbreak) and to have something inside (junk food may contain harmful chemicals). "Check" fits only sentence (i), "incorporate" could loosely fit only sentence (ii), and "blame" fits neither. The noun "containment" carries the first sense, as in the Cold War "policy of containment".

Answer: (D) ebullient

"Ebullient" (from Latin "ebullire", to boil over) means cheerful, lively and full of energy, so it can describe both an exuberant nature and a festive mood. "Excitable" means easily excited or nervous and is not a compliment; "exorbitant" means unreasonably high, usually of prices; and "exciting" means causing excitement, which describes an event rather than a person's temperament. Noun: ebullience. Synonyms: buoyant, effervescent, vivacious, high-spirited.

Answer: (D) He said that he would go there the next day.

In indirect speech after a past reporting verb, the pronoun changes to suit the speaker (I → he), "will" back-shifts to "would", and "tomorrow" becomes "the next day" (or "the following day"): He said that he would go there the next day. Option (A) leaves the pronoun unchanged, (B) uses "told" without an object and keeps "shall", and (C) does not back-shift the tense. Other standard changes: today → that day, yesterday → the previous day, now → then, here → there, this → that, ago → before.

Answer: (B) a stitch in time saves nine

"A stitch in time saves nine" means that dealing with a problem at once prevents it from becoming bigger, which is the reason for not delaying. "Beggars can't be choosers" means people in need must accept what they are given; "a bad workman blames his tools" means an unskilled person blames the equipment for his own failure; and "all's fair in love and war" means any method is justified in certain situations. Proverbs with a similar message: "procrastination is the thief of time" and "strike while the iron is hot".

Answer: (C) Subjunctive mood

The sentence describes an unreal or hypothetical condition ("if I could"), which is the mark of the subjunctive mood, used for wishes, suppositions and conditions contrary to fact ("If I were you...", "I wish I were rich"). The indicative mood states facts or asks about them, and the imperative mood gives commands or requests ("Go there"). English traditionally has just these three moods; "interrogative" is a type of sentence rather than a mood, though it is offered here as a distractor.

Answer: (C) Sir Syed Ahmad Khan

Sir Syed Ahmad Khan said this while opposing the Congress in his Lucknow (1887) and Meerut (1888) speeches, arguing that representative government would mean rule by the Hindu majority. He founded the United Indian Patriotic Association (1888) with Raja Shiv Prasad of Benares to counter the Congress, having earlier founded the MAO College at Aligarh (1875). Lord Dufferin, the Viceroy when the Congress was born, dismissed it as representing a "microscopic minority"; Lord Curzon said the Congress was "tottering to its fall"; and Jinnah was in fact a Congress member from 1906 before joining the Muslim League in 1913.

Answer: (C) Guru Govind

Guru Gobind Singh (born at Patna in 1666, Guru from 1675 to 1708) was the tenth and last human Guru. He founded the Khalsa at Anandpur Sahib on Baisakhi day in 1699, introduced the five Ks and, before his death at Nanded in 1708, declared the Guru Granth Sahib to be the eternal Guru. Of the other options, Guru Ram Das (4th) founded Amritsar, Guru Hargobind (6th) built the Akal Takht and adopted the miri-piri doctrine, and Guru Tegh Bahadur (9th), his father, was executed in Delhi on Aurangzeb's orders in 1675. Guru Nanak was the first Guru and Guru Arjan Dev (5th) compiled the Adi Granth.

Answer: (A) opening the temples to the low castes Hindus

The Vaikom Satyagraha (1924–25) in the princely state of Travancore demanded that "lower-caste" Hindus (Ezhavas, Pulayas and others) be allowed to use the roads around the Vaikom Mahadeva temple; it was the first organised temple-entry type movement in Kerala. Its leaders included T. K. Madhavan, K. Kelappan and K. P. Kesava Menon; E. V. Ramasamy "Periyar" took part and earned the title "Vaikom Veerar", and Gandhi visited in 1925. It paved the way for the Guruvayur Satyagraha (1931–32) and the Temple Entry Proclamation of 1936. Tenant struggles against landlords and the demand for responsible government in Travancore (State Congress, 1938) were separate movements.

Answer: (A) D, C, A, B

C is older than D but younger than B, so B > C > D. A is "older but not eldest", i.e. A is older than C yet younger than B, giving B > A > C > D. In ascending order of age (youngest first) this is D, C, A, B. Check the other options: (B) puts C before D although C is older; (C) makes A the eldest, which is ruled out; and (D) starts with the eldest, B, so it is not ascending at all. In such questions always note whether ascending or descending order is asked.

Answer: (D) Pineal body-thyroid

The pineal body (epiphysis), a pea-sized structure in the brain weighing only about 0.1–0.2 g, is the smallest endocrine gland; it secretes melatonin, which regulates the sleep–wake cycle. The thyroid, in the neck and weighing about 25–30 g, is the largest purely endocrine gland; it secretes thyroxine (T4) and T3, which need iodine, and calcitonin. The pituitary (about 0.5 g) is called the master gland but is neither the smallest nor the largest, and the ovary is a gonad with a secondary endocrine role. Do not confuse this with the liver, which is the largest gland of the body overall, or the pancreas, a mixed (heterocrine) gland.

Answer: (C) Dr. Rajendra Prasad

PSC's official key (provisional and final) marks Dr. Rajendra Prasad, and that is recorded here as the answer. Standard history texts, however, say that Gandhi chose Acharya Vinoba Bhave as the first Individual Satyagrahi (he offered satyagraha at Paunar on 17 October 1940), Jawaharlal Nehru as the second and Brahma Datt as the third; Vinoba's name is not among the options. The Individual Satyagraha was launched after the Congress rejected the August Offer (1940) and aimed to assert the right of free speech against India's forced participation in the War, with the "Delhi Chalo" call. For any other exam, remember: first Vinoba Bhave, second Nehru.

Answer: (C) rstr

The series is the block "strs" repeated four times: strs / strs / strs / strs. Writing out the 16 letters, the given ones are s, t, _, s, _, t, r, s, s, _, r, s, s, t, _, s, so the four blanks must be r, s, t and r in that order, i.e. "rstr". Check: st(r)s (s)trs s(t)rs st(r)s. For such questions, count the total number of letters (given letters plus blanks) and look for a repeating block whose length divides that total, here 16 = 4 × 4.

Answer: (B) Montagu Declaration

After Montagu's August Declaration of 1917, the Montagu–Chelmsford reform proposals appeared in July 1918. A special Congress session at Bombay (August 1918) called them "disappointing and unsatisfactory", whereupon the Moderates led by Surendranath Banerjea, who wished to accept them, walked out and formed the National Liberal Federation (1918–19). That was the second split. The Lucknow Pact (1916) was the Congress–League accord made at the very session where Moderates and Extremists reunited after the Surat Split of 1907, and Annie Besant's election as the first woman President (Calcutta, 1917) caused no split.

Answer: (C) 11

Each number on one half of the wheel is linked to the number diametrically opposite it by the rule $n \rightarrow 2n+1$: opposite 2 is $2\times2+1=5$, opposite 3 is $2\times3+1=7$, and opposite 4 is $2\times4+1=9$. The sector marked "?" lies opposite 5, so it must be $2\times5+1=11$. In wheel or circle puzzles, first test the relation between opposite sectors, then between adjacent sectors, and only then look for a running series around the rim.

Answer: (C) 2 and 4 only

A measure is inflationary if it increases liquidity and the money supply. Lowering the SLR and abolishing the CRR both release funds that banks can lend, so statements 2 and 4 are inflationary. When the RBI sells new bonds (an open-market sale) it absorbs money from the system, and raising the Bank Rate makes borrowing costlier; both are contractionary, so statements 1 and 3 are wrong. Remember: CRR is the share of deposits kept as cash with the RBI (no interest earned), while SLR is the share kept by the bank itself in liquid assets such as gold and government securities. Other quantitative tools are the repo and reverse repo rates, MSF and OMO.

Answer: (B) Under both Preamble and Directive Principles

The Preamble secures to all citizens "JUSTICE, social, economic and political", an ideal borrowed from the Russian Revolution (liberty, equality and fraternity come from the French Revolution). PSC's key accepts option 'A' i.e. "only under the Preamble". Be aware, though, that Article 38(1) in the Directive Principles also speaks of "a social order in which justice, social, economic and political, shall inform all the institutions of the national life", which is why several guidebooks prefer "both Preamble and Directive Principles". The Fundamental Rights chapter does not use the phrase. The Preamble has been amended only once, by the 42nd Amendment (1976), which added "Socialist", "Secular" and "Integrity".

Answer: (B) released

When two drops merge, the total volume stays the same but the total surface area falls. Two drops of radius $r$ have area $8\pi r^2$, while the merged drop of radius $2^{1/3}r$ has area of only about $6.35\pi r^2$. Since surface energy = surface tension × area, the surplus energy is released, mostly as heat, and the liquid warms slightly. The reverse also holds: breaking one drop into many needs work, so energy is absorbed. Specific heat has nothing to do with the direction of the energy change. Surface tension is also why free drops are spherical (least area for a given volume); it falls as temperature rises or when a detergent is added.

Answer: (B) Rajasthan

Answer as of 2023 — this may have changed since.

PSC's final answer key gives Rajasthan (the provisional key had given Uttar Pradesh), and that is recorded here. Official crop statistics do not really support either: in 2021–22 pulse yields were roughly Gujarat 1,530 kg/ha, Uttar Pradesh 1,080, Madhya Pradesh 1,065 and Rajasthan only about 630 kg/ha (RBI Handbook of Statistics on Indian States). What is true of Rajasthan is that it has the largest area under pulses, while Madhya Pradesh is the largest producer. Other facts: India is the world's largest producer, consumer and importer of pulses; gram (chana) is the leading pulse; pulses fix atmospheric nitrogen through Rhizobium bacteria; and 10 February is World Pulses Day.

Answer: (B) Ease of doing business

The Jan Vishwas (Amendment of Provisions) Bill was introduced in the Lok Sabha on 22 December 2022 by Commerce and Industry Minister Piyush Goyal and, after scrutiny by a Joint Parliamentary Committee, became an Act in 2023. It amends 42 Central Acts administered by 19 ministries and decriminalises 183 provisions, replacing imprisonment for minor, technical and procedural defaults with monetary penalties. Its declared aim is to promote ease of living and ease of doing business through "trust-based governance". It has nothing to do with terrorism, malnutrition or police reforms.

Answer: (B) Bangkok

The Asian-Pacific Postal Union (APPU) was founded on 1 April 1962 following a convention signed at Manila in 1961; it has 32 member countries and its headquarters is in Bangkok, Thailand. It is a "restricted union" of the Universal Postal Union (UPU, founded 1874, headquarters Bern, a UN specialised agency; World Post Day is 9 October). India's Vinaya Prakash Singh took over as its Secretary General in January 2022. Manila is the seat of the Asian Development Bank, Colombo gave its name to the Colombo Plan, and Bangkok also hosts UN ESCAP.

Answer: (B) Aluminium metal

The thermite (aluminothermic or Goldschmidt) reaction is $Fe_2O_3 + 2Al \rightarrow 2Fe + Al_2O_3 + \text{heat}$. Aluminium removes oxygen from iron(III) oxide and is itself oxidised, so aluminium metal is the reducing agent, while iron oxide is the oxidising agent. Aluminium oxide and iron are merely the products. The reaction is a highly exothermic displacement reaction, possible because aluminium lies above iron in the reactivity series; the molten iron produced is used to join rails and repair cracked machine parts. The same method is used to obtain chromium and manganese from their oxides.

Answer: (B) Iron ore mining area

The Rourkela Steel Plant (Sundargarh district, Odisha), set up in 1959 with West German collaboration during the Second Five Year Plan, was located on the basis of proximity to raw material: it stands in the iron-ore belt of Sundargarh and Kendujhar (Bonai, Barsua, Kiriburu). Its coal comes from farther away (Jharia and Talcher), hydel power from Hirakud and water from the Koel and Sankh rivers. It is therefore an iron-ore-based location, not a coalfield or Damodar Valley location like Durgapur and Bokaro. Compare: Bhilai (Chhattisgarh, Soviet help) uses Dalli-Rajhara ore, Durgapur (West Bengal) had British help, and Bokaro (Jharkhand) Soviet help.

Answer: (D) 44

B did better than A and exactly two students stand between them, so B's rank from the top is $10-3=7$. B is thus 7th from the top and 38th from the bottom, and the total number of students is $7+38-1=44$. The general rule is: total = (rank from top) + (rank from bottom) − 1, because the person concerned is counted twice. Had B been worse than A, B would have been 13th from the top and the total would have been 50, which is not among the options.

Answer: (C) Reserved Forest

Under the Indian Forest Act, 1927, Reserved Forests are the most restricted category: every activity (entry, grazing, collection of produce) is prohibited unless specifically permitted. In Protected Forests it is the other way round — activities are allowed unless specifically prohibited — and local people keep many rights. National Parks and Wildlife Sanctuaries are protected areas under the Wildlife (Protection) Act, 1972, where regulated public entry and tourism are allowed. Reserved forests make up more than half of India's recorded forest area; the third legal category is village or unclassed forest.

Answer: (C) Abul Kalam Azad

Maulana Abul Kalam Azad became Congress President at the Ramgarh session in 1940 and remained in office until 1946, because no annual sessions could be held during the War and the Quit India years. This six-year stretch is the longest continuous tenure before independence, and as President he negotiated with the Cripps Mission and the Cabinet Mission. Nehru presided in consecutive years (1929–30 and 1936–37) but never for six in a row; Dadabhai Naoroji was President three times, but in 1886, 1893 and 1906; and Gokhale presided only once (Benares, 1905). Azad's birthday, 11 November, is observed as National Education Day.

Answer: (C) Ibrahim Lodi

Ibrahim Lodi (1517–26) was the last Sultan of Delhi; he was defeated and killed by Babur at the First Battle of Panipat on 21 April 1526. The Sultanate's five dynasties in order are: Mamluk or Slave (1206–90), Khalji (1290–1320), Tughlaq (1320–1414), Sayyid (1414–51) and Lodi (1451–1526), the Lodis being the only Afghan dynasty. Bahlul Lodi founded the Lodi dynasty; Sikandar Lodi founded Agra (1504) and introduced the Gaz-i-Sikandari measure; Firuz Tughlaq (1351–88) is remembered for canals, new towns and making the jizya a separate tax.

Answer: (B) Zonal council

Zonal Councils are statutory (not constitutional) bodies created by Part III of the States Reorganisation Act, 1956. There are five — Northern, Central, Eastern, Western and Southern — each chaired by the Union Home Minister, with the Chief Ministers acting as vice-chairman by rotation; the North Eastern Council was set up separately by a 1971 Act. The Inter-State Council comes from Article 263 and was set up in 1990 on the Sarkaria Commission's recommendation; the Sarkaria Commission itself (1983) examined Centre–State relations; and the Official Language Commission was appointed under Article 344. (The booklet prints "wide" for "vide".)

Answer: (B) Geneva

The WTO, successor to GATT, came into being on 1 January 1995 under the Marrakesh Agreement and has its headquarters in Geneva; its Appellate Body sits there too. The Appellate Body is a standing body of seven members who hear appeals from dispute-settlement panels, but it has been unable to function since December 2019 because the United States has blocked new appointments. New York houses the UN headquarters; Paris has UNESCO and the OECD; The Hague has the International Court of Justice, the International Criminal Court and the OPCW. Geneva also hosts the WHO, ILO, WIPO, WMO, ITU and UNCTAD.

Answer: (B) Akbar

Akbar promulgated Din-i-Ilahi (also called Tauhid-i-Ilahi, "divine monotheism") in 1582. It grew out of the religious debates in the Ibadat Khana at Fatehpur Sikri (built 1575), the Mahzar of 1579 and his policy of Sulh-i-kul (peace with all). It had no scripture, priesthood or place of worship, and Birbal was the only prominent Hindu to join. Babur founded the Mughal empire and wrote the Baburnama; Jahangir wrote the Tuzuk-i-Jahangiri and installed the chain of justice; Shah Jahan built the Taj Mahal, Red Fort and Jama Masjid.

Answer: (D) Paddy fields

Flooded paddy fields have waterlogged, oxygen-free soil in which methanogenic bacteria decompose organic matter and release methane ($CH_4$), also known as marsh gas. Flower gardens, orchards and tea gardens stand on well-drained soils and emit very little. India's other large methane sources are enteric fermentation in ruminant livestock (the biggest single source), landfills, coal mines and biomass burning. Methane is the main constituent of natural gas, CNG and biogas, and has about 28 times the warming effect of $CO_2$ over 100 years. Emissions from rice can be cut by alternate wetting and drying, direct seeding and the System of Rice Intensification.

Answer: (C) Madras/Chennai

OTEC produces power from the temperature difference (about 20°C or more) between warm surface water and cold deep water in tropical seas. India's OTEC efforts have centred on Tamil Nadu: a 1 MW plant was proposed off the Tamil Nadu coast in the early 1980s, and the National Institute of Ocean Technology (NIOT), Chennai, later built an experimental 1 MW floating OTEC plant and now runs low-temperature thermal desalination (LTTD) plants in Lakshadweep, which work on the same principle. Hence Madras/Chennai is the answer; Kolkata, Haldia and Paradip have no OTEC link. For tidal energy, the potential sites are the Gulf of Khambhat, the Gulf of Kachchh and the Sundarbans.

Answer: (A) To protect monument of national importance

The Fundamental Duties (Article 51A, Part IVA) were added by the 42nd Amendment, 1976, on the Swaran Singh Committee's recommendation and are modelled on the USSR constitution; an eleventh duty was added by the 86th Amendment, 2002. "To develop the scientific temper, humanism and the spirit of inquiry and reform" is duty 51A(h), and "to uphold and protect the sovereignty, unity and integrity of India" is 51A(c). Protection of monuments and places of national importance, however, is an obligation of the State under Article 49, a Directive Principle. The nearest citizen's duty, 51A(f), is to value and preserve the rich heritage of our composite culture.

Answer: (D) All of the above

Water is a polar solvent and dissolves polar substances ("like dissolves like"). Glucose has several –OH groups, urea has –NH$_2$ and C=O groups, and acetone has a polar carbonyl group; all three form hydrogen bonds with water and dissolve, acetone being miscible in all proportions. Non-polar substances such as oil, wax, naphthalene and benzene do not dissolve. Extra facts: acetone (propanone) is the solvent in nail-polish remover; urea was the first organic compound made from inorganic material (Wöhler, 1828) and is a fertiliser with 46% nitrogen; glucose is $C_6H_{12}O_6$.

Answer: (C) Abul Kalam Azad

Maulana Abul Kalam Azad presided over the special session of the Congress at Delhi in September 1923 at the age of 35, the youngest person to hold the office. Born in Mecca in 1888, he edited Al-Hilal and Al-Balagh and later became free India's first Education Minister. Rash Behari Ghosh presided at Surat (1907) and Madras (1908) as an elderly Moderate; Subhas Chandra Bose was 41 at Haripura (1938); and Lala Lajpat Rai presided over the Calcutta special session of 1920. The oldest President was Dadabhai Naoroji, aged 81 at Calcutta in 1906.

Answer: (A) Ministry of Commerce and Industry

The Open Network for Digital Commerce (ONDC) is an initiative of the Department for Promotion of Industry and Internal Trade (DPIIT) under the Ministry of Commerce and Industry. It was incorporated as a not-for-profit Section 8 company in December 2021, and its pilot phase began on 29 April 2022 in five cities: Delhi NCR, Bengaluru, Bhopal, Shillong and Coimbatore. ONDC is an open, interoperable network (often called the "UPI of e-commerce") meant to end the dominance of a few large platforms and bring small retailers online. The Ministry of Electronics and IT handles Digital India, DigiLocker and UMANG.

Answer: (A) East Bengal and Bengal

Lord Curzon's partition, effective 16 October 1905, created (i) the new province of Eastern Bengal and Assam, with its capital at Dacca and a Muslim majority, and (ii) a reduced province of Bengal, made up of western Bengal with Bihar and Orissa, with its capital at Calcutta. Hence "East Bengal and Bengal"; "West Bengal" as a name dates only from 1947, and Assam was merged into the eastern province rather than forming a separate one. The partition set off the Swadeshi and Boycott movement and was annulled at the Delhi Durbar of 1911, when the capital was also shifted to Delhi; Bihar and Orissa were then separated in 1912.

Answer: (A) 4%

Candidates who failed in at least one subject = $55+65-24=96\%$ (inclusion–exclusion, since the 24% who failed in both would otherwise be counted twice). Therefore those who passed in both subjects = $100-96=4\%$. As a check: failed in English only = $55-24=31\%$, failed in Mathematics only = $65-24=41\%$, failed in both = 24%, and $31+41+24=96\%$. A Venn diagram of two overlapping circles makes such questions quick.

No option is correct as printed — this question is disputed.

PSC cancelled this question in its final answer key and gave one mark to every candidate. The provisional key had marked Jatindranath Mukherjee ("Bagha Jatin"), the Jugantar leader who coordinated the Indo-German arms plot in Bengal and died after the gunfight at Balasore (Orissa) in September 1915. Strictly speaking, however, the Ghadar Party (founded 1913 at San Francisco; Sohan Singh Bhakna president, Lala Har Dayal the moving spirit) was based among Punjabis, and its 1915 rising in India was organised by Rash Behari Bose and Sachindranath Sanyal. Of the others, Jatindranath Das died after a 63-day hunger strike in Lahore jail (1929), Barindra Ghosh belonged to the Alipore Bomb Case group and M. N. Roy went abroad for German arms and later founded the Communist Party of India at Tashkent (1920). CANCELLED BY PSC. The final answer key (24.05.2024) marks this question '*' and awards 1 mark to all candidates irrespective of attempt. correct_answer 'A' (Jatindranath Mukherjee) is only the provisional-key (22.12.2023) answer, kept so the record stays usable.

Answer: (A) Interest payments

In the Union Budget 2023–24 (presented on 1 February 2023), total expenditure was estimated at about ₹45.03 lakh crore, of which interest payments were about ₹10.80 lakh crore (roughly 24%), the largest single item. In the "Rupee Goes To" chart, interest payments take 20 paise, States' share of taxes and duties 18, central sector schemes 17, centrally sponsored schemes 9, Finance Commission and other transfers 9, defence 8, subsidies 7 and pensions 4. Note that the States' share of taxes is devolution, not the Centre's own spending. The same Budget set capital expenditure at ₹10 lakh crore and the fiscal deficit at 5.9% of GDP.

Answer: (C) Mumbai

Khadi Fest 2022, organised by the Khadi and Village Industries Commission (KVIC) to mark Gandhi Jayanti, was inaugurated in Mumbai in October 2022 by the Union MSME Minister, Narayan Rane, and was held after a gap of two years. KVIC is a statutory body set up in 1957 under the KVIC Act, 1956; it works under the Ministry of MSME and its headquarters is in Mumbai, where the Fest is held every year. Do not confuse it with the "Khadi Utsav" on the Sabarmati riverfront at Ahmedabad (August 2022), where 7,500 women spun the charkha together.

Answer: (D) All of the above

The balanced equation is $2Mg + O_2 \rightarrow 2MgO$ (the equation printed in the paper is unbalanced). Two substances join to give a single product, so it is a combination reaction. Magnesium gains oxygen and loses electrons (0 to +2), so it is an oxidation — strictly a redox reaction, since oxygen is reduced. Heat and a dazzling white light are given out, so it is exothermic. Hence all three descriptions apply. The white ash, magnesium oxide, is a basic oxide; dissolved in water it forms $Mg(OH)_2$, which turns red litmus blue.

Answer: (A) Rajendra Chola I

Rajendra Chola I (1014–44), son of Rajaraja I, sent his army north up to the Ganga, defeating Mahipala I of Bengal (c. 1023). To commemorate it he took the title Gangaikonda ("conqueror of the Ganga") and built a new capital, Gangaikondacholapuram, with its own Brihadisvara temple. His naval expedition against Srivijaya (1025) gave him the title Kadaram Kondan. Rajaraja I (985–1014) built the Brihadisvara temple at Thanjavur; Rajadhiraja died fighting the Chalukyas at Koppam (1054); and Rajendra II was crowned on that very battlefield.

Answer: (A) first

Answer as of 2023 — this may have changed since.

India has the world's largest bovine herd: the 20th Livestock Census (2019) counted about 193 million cattle and 110 million buffaloes out of a total livestock population of roughly 536 million. Counting cattle and buffaloes together India is far ahead of Brazil, China and the USA, which is why standard textbooks rank India first in cattle rearing. India has also been the world's largest milk producer since 1998 and has more than half of the world's buffaloes. The livestock census is taken every five years; the first was in 1919.

Answer: (B) 21-08-2002

The gaps between successive dates grow by one day each time: 18 July to 25 July is 7 days; 25 July to 2 August is 8 days (July has 31 days); 2 August to 11 August is 9 days. The next gap must be 10 days, and 11 August + 10 days = 21-08-2002. The usual slip is to forget that July has 31 days when counting across the month-end. Months with 31 days: January, March, May, July, August, October and December.

Answer: (C) 7

Total teaching periods per day = $3\times6$ (Classes VI, VII, VIII) $+\ 2\times7$ (Classes IX, X) $=18+14=32$. Each teacher can take at most 5 periods, so the number of teachers needed is at least $32\div5=6.4$, i.e. 7 after rounding up. Six teachers could cover only 30 periods, which is short by 2. Seven teachers can cover 35 periods, and since only five classes run at any one time, a workable timetable exists. In "minimum number" questions always round up, never down.

Answer: (A) Russia

The idea of five-year planning was taken from the Soviet Union, where Stalin launched the first Five-Year Plan in 1928. Strictly, the plans are not in the Constitution: the Planning Commission was created by a Cabinet resolution on 15 March 1950 as an extra-constitutional, non-statutory body, and the First Plan covered 1951–56. Twelve plans were completed before NITI Aayog replaced the Commission on 1 January 2015. Also from the USSR: Fundamental Duties and the ideal of social, economic and political justice. From England: parliamentary government and rule of law. From the USA: Fundamental Rights and judicial review. From Weimar Germany: suspension of Fundamental Rights during an emergency.

Answer: (C) Cloud bursts

Ladakh is a cold desert in the rain shadow of the Himalaya with less than 10 cm of rain a year, so its mud-built houses and loose slopes cannot withstand sudden downpours. A cloudburst, defined by the IMD as rainfall of over 10 cm in an hour over a small area, triggers flash floods and mudflows; the Leh cloudburst of 5–6 August 2010 killed over 200 people. Frontal rain belongs to temperate cyclones, convectional rain to hot equatorial regions, and hailstorms damage crops rather than cause mass deaths.

Answer: (B) Parliament

Clauses (2) to (6) of Article 19 allow "the State" to impose reasonable restrictions "by law", so the power belongs to the legislature, i.e. Parliament (and State legislatures within their own fields). The Supreme Court does not impose restrictions; it decides, through judicial review under Articles 13 and 32, whether a restriction is reasonable. The President can suspend the enforcement of Fundamental Rights during a national emergency (Article 359), which is a different power. Parliament alone can also modify the rights of members of the armed forces (Article 33). The grounds in Article 19(2) include sovereignty and integrity of India, security of the State, public order, decency or morality, contempt of court and defamation.

Answer: (D) 835961264

From PARDON = 721890 we get P=7, A=2, R=1, D=8, O=9, N=0. From MERCY = 53164 we get M=5, E=3, R=1, C=6, Y=4 (R is 1 in both, which confirms the code). So DEMOCRACY = D(8) E(3) M(5) O(9) C(6) R(1) A(2) C(6) Y(4) = 835961264. Options (A), (B) and (C) each change one or two digits (a 7 for 6, or 5 and 3 interchanged), so compare the options digit by digit instead of trusting a quick glance.

Answer: (B) the Consolidated Fund of India

All revenues, loans raised and loan repayments received by the Union form the Consolidated Fund of India (Article 266(1)), and no money can be withdrawn from it except under an Appropriation Act passed by Parliament (Article 114). The Public Account (Article 266(2)) holds money such as provident funds and small savings, for which the government acts as banker; payments from it need no parliamentary appropriation. The Contingency Fund (Article 267) is placed at the President's disposal to meet unforeseen expenditure, and Parliament's approval is obtained afterwards. Expenditure "charged" on the Consolidated Fund, such as the salaries of the President and judges, is discussed but not voted.

Answer: (D) Volume

Mass, and therefore volume for a liquid of fixed density, is conserved when a drop is divided: $R^3=r_1^3+r_2^3$. Radii do not add up in this way. The total surface area of the two smaller drops is greater than that of the original drop, so the total surface energy (surface tension × area) is also greater; that is why work has to be done to break a drop. This is the reverse of the case where two drops merge and energy is released.

Answer: (C) Srilanka

Sri Lanka (then Ceylon) became independent of Britain on 4 February 1948 and celebrated its 75th Independence Day on 4 February 2023; it became a republic and took the name Sri Lanka in 1972. Nepal and Bhutan were never colonised, so they have no independence day (Bhutan's National Day is 17 December), and Bangladesh marks Independence Day on 26 March (1971) and Victory Day on 16 December. Other neighbours: Myanmar, 4 January 1948; Pakistan, 14 August 1947; Maldives, 26 July 1965.

Answer: (B) China

China is the country linked with an "artificial moon". In early 2022 Chinese scientists were reported to have built a research facility at Xuzhou (Jiangsu) that uses powerful magnetic fields to simulate the Moon's low gravity (one-sixth of Earth's) for testing lunar equipment. Earlier, in 2018, Chengdu had announced plans for an "illumination satellite" to light the city at night. China is also known for its "artificial sun", the EAST fusion reactor at Hefei, and for the Chang'e lunar missions (Chang'e-4 made the first landing on the far side in 2019).

Answer: (B) 12

Let $x$ be the number of ₹200 notes and $y$ the number of ₹100 notes. Then $x+y=48$ and $200x+100y=6000$, i.e. $2x+y=60$. Subtracting the first equation from the second gives $x=12$, so $y=36$. Check: $12\times200+36\times100=2400+3600=6000$. Option (C) 36 is the number of ₹100 notes, placed there to catch candidates who do not read which denomination is asked. Shortcut: if all 48 notes were ₹100 the amount would be ₹4,800; the shortfall of ₹1,200 is made up at ₹100 per ₹200 note, giving 12 notes.

Answer: (C) Aurangzeb

Aurangzeb (reigned 1658–1707) took the title Alamgir ("seizer of the world") at his coronation; he is called Alamgir I because a later Mughal, Alamgir II, ruled from 1754 to 1759. Aurangzeb reimposed the jizya (1679), had Guru Tegh Bahadur executed (1675), annexed Bijapur (1686) and Golconda (1687), and died at Ahmednagar. Titles of the others: Akbar was Jalaluddin Muhammad, Jahangir was Nuruddin Muhammad (Salim), and Bahadur Shah II "Zafar" was the last Mughal emperor, exiled to Rangoon after 1857. Bahadur Shah I was also known as Shah Alam I.

Answer: (C) Dhaka

BIMSTEC (Bay of Bengal Initiative for Multi-Sectoral Technical and Economic Cooperation) was founded by the Bangkok Declaration of 6 June 1997. It has seven members — Bangladesh, Bhutan, India, Nepal and Sri Lanka from South Asia, and Myanmar and Thailand from South-East Asia — and its permanent secretariat has been in Dhaka since 2014. Its charter was adopted at the fifth summit (Colombo, 2022). For comparison: the SAARC secretariat is at Kathmandu, ASEAN's at Jakarta, IORA's at Ebene (Mauritius), and Colombo is associated with the Colombo Plan.

Answer: (C) Farrukhshiyar

Farrukhsiyar (1713–19) issued the farman of 1717, often called the "Magna Carta of the Company". It allowed the English East India Company to trade in Bengal free of duties for an annual payment of ₹3,000, to issue dastaks (passes) for its goods and to rent more villages around Calcutta. It was obtained by the Surman embassy, helped by the surgeon William Hamilton, who had cured the emperor. Misuse of dastaks later caused friction with the Nawabs of Bengal and led towards Plassey. Shah Alam II granted the Diwani in 1765; Muhammad Shah "Rangeela" faced Nadir Shah's invasion in 1739; Bahadur Shah II was the emperor of 1857.

Answer: (A) sown in S. W. Monsoon season and harvested in winter

Aman is the winter (kharif) rice crop: it is sown or transplanted in June–July with the south-west monsoon and harvested in winter, November–December. It is by far the most important rice crop of West Bengal. Aus is the autumn crop, sown with pre-monsoon showers in summer and harvested in August–September, which is what options (C) and (D) roughly describe. Boro is the irrigated summer crop, sown in winter and harvested in April–May. Memory aid: Aus – autumn, Aman – winter, Boro – summer.

Answer: (A) 12.5 Ω

Resistance is greatest when all resistors are joined in series, where the values simply add: $R_s=5+4.5+3=12.5\ \Omega$. In parallel the equivalent resistance is always less than the smallest resistor: $\dfrac{1}{R_p}=\dfrac{1}{5}+\dfrac{1}{4.5}+\dfrac{1}{3}$ gives about $1.3\ \Omega$. No mixed arrangement can exceed the series value, so 13.5, 14.5 and 16.5 Ω are impossible. Remember: in series the current is the same through each resistor; in parallel the voltage is the same across each, which is why household appliances are wired in parallel.

Answer: (A) 20

Work from the innermost brackets. $7*2$: since $7>2$, it is $7-2=5$. Then $5*5$: the numbers are equal, so it is $2\times5=10$. Next $5*7$: since $5<7$, it is $5+7=12$. Then $12*2$: since $12>2$, it is $12-2=10$. Adding the two parts, $10+10=20$. The trap lies in the middle step: after the first bracket becomes 5, the operation $5*5$ must use the "equal" rule ($2x$), not addition or subtraction.

Answer: (A) Food

In the Budget Estimates for 2023–24 the three major subsidies were food at about ₹1.97 lakh crore, fertiliser at about ₹1.75 lakh crore and petroleum at only about ₹2,257 crore, so food took the largest share. The food subsidy is paid mainly through the Food Corporation of India to supply grain under the National Food Security Act, 2013 and the PM Garib Kalyan Anna Yojana (free grain to about 81 crore people from 1 January 2023). "Interest" is the largest expenditure head but it is not a subsidy. The fertiliser subsidy covers urea (price-controlled) and P&K fertilisers (Nutrient Based Subsidy).

Answer: (B) North American History, to connote an assembly of people

At the first session in Bombay in December 1885 the proposed "Indian National Union" was renamed the Indian National Congress, a suggestion credited to Dadabhai Naoroji. The word was taken from North American history, where "Congress" meant an assembly of the people's delegates, rather than copied from the name of the US legislature as such. The Chicago Parliament of the World's Religions (1893) and the All India Trade Union Congress (1920) both came later. Basics: the Congress was founded on 28 December 1885 at Gokuldas Tejpal Sanskrit College, Bombay, with 72 delegates; W. C. Bonnerjee was the first President, A. O. Hume the founder and Lord Dufferin the Viceroy.

Answer: (D) One large circle containing two small circles that overlap each other

"Books" is the widest class, so it is the large circle. Every Bengali book is a book and every novel is a book, so both small circles must lie wholly inside the large one. Some Bengali books are novels (and some novels are Bengali books), so the two small circles must overlap each other. Only the last diagram shows this. The first diagram would suit two unrelated sub-classes such as "books, novels, dictionaries"; the diagrams in which a small circle crosses the boundary of the large one would wrongly mean that some Bengali books or novels are not books.

Answer: (B) .02

Each bracket has the form $1-\dfrac{1}{n}=\dfrac{n-1}{n}$, so the product is $\dfrac{2}{3}\times\dfrac{3}{4}\times\dfrac{4}{5}\times\cdots\times\dfrac{98}{99}\times\dfrac{99}{100}$. Every numerator cancels with the denominator just before it (a telescoping product), leaving only the first numerator and the last denominator: $\dfrac{2}{100}=0.02$. Note that the product starts at $\dfrac{1}{3}$, not $\dfrac{1}{2}$; if it had started at $\dfrac{1}{2}$ the answer would have been $\dfrac{1}{100}=0.01$, which is the trap in option (A).

Answer: (D) Investment spending by public companies

Public expenditure is spending by the government itself (Centre, States and local bodies) out of its budget. A subsidy to a city bus service, defence spending and interest on the national debt are all budgetary outlays. Investment by public sector companies out of their own internal resources and market borrowings is the spending of commercial enterprises and is not counted in the government's budget, so it is the odd one out. Useful theory: Wagner's law states that public expenditure grows as an economy develops, and Peacock and Wiseman put forward the "displacement effect".

Answer: (B) Jawaharlal Nehru

Gaidinliu (1915–93), a Rongmei Naga from Manipur, joined her cousin Haipou Jadonang's Heraka movement at the age of 13 and led the revolt after he was hanged in 1931; she was captured in 1932, aged 16, and sentenced to life imprisonment. Jawaharlal Nehru met her in Shillong jail in 1937, called her the "daughter of the hills" and gave her the title "Rani". She was released only after independence and received the Padma Bhushan in 1982. Thakkar Bapa (A. V. Thakkar) is remembered for work among tribals and Harijans, but had no part in this.

Answer: (B) Yellow precipitation of lead iodide is formed.

$Pb(NO_3)_2 + 2KI \rightarrow PbI_2\downarrow + 2KNO_3$. This is a double displacement (precipitation) reaction in which insoluble lead iodide separates as a bright yellow precipitate, while potassium nitrate stays in solution. Colours of other common precipitates: $BaSO_4$ and $AgCl$ are white, $AgBr$ is pale yellow, $AgI$ is yellow, $Cu(OH)_2$ is blue, $Fe(OH)_3$ is reddish-brown, and $PbS$ and $CuS$ are black. White, red and black are therefore all wrong for lead iodide.

Answer: (D) Peru

Ardeshir B. K. Dubash, a Mumbai-based industrialist who has been Honorary Consul of Peru in Mumbai since 1973, received the "Order of Merit in the Diplomatic Service of Peru José Gregorio Paz Soldán", among the highest honours of Peru's Foreign Ministry, for strengthening India–Peru ties. Peru facts: capital Lima, currency sol, the Inca site of Machu Picchu, and Lake Titicaca shared with Bolivia. For comparison, France's top honour is the Legion of Honour, Japan confers the Order of the Rising Sun and Canada the Order of Canada.

Answer: (C) Chikmagalore

The Central Coffee Research Institute (CCRI), started in 1925 as the Mysore Coffee Experimental Station, is at Balehonnur in Chikkamagaluru (Chikmagalur) district, Karnataka. Coffee was first grown in India on the nearby Baba Budan hills around 1670. Karnataka produces about 70% of India's coffee, followed by Kerala and Tamil Nadu; the Coffee Board's head office is in Bengaluru. Munnar is a tea centre, and Mysuru has the Central Food Technological Research Institute. Other crop institutes: tea – Tocklai (Jorhat), rubber – Kottayam, spices – Kozhikode, rice – Cuttack, jute – Barrackpore, cotton – Nagpur, potato – Shimla.

Answer: (B) Pulakeshin II

Pulakeshin II (c. 610–642) of the Chalukyas of Badami (Vatapi) stopped Harshavardhana on the banks of the Narmada, which then became the boundary between the two empires. The victory is recorded in the Aihole inscription (634 CE) composed by his court poet Ravikirti, and he took the title Dakshinapatheshvara. Hiuen Tsang visited his kingdom. He was finally defeated and killed by the Pallava king Narasimhavarman I, who took the title Vatapikonda. Pulakeshin I founded the dynasty, Kirtivarman I was his son, and Mangalesha was the uncle whom Pulakeshin II overthrew to gain the throne.

Answer: (C) 1896

Tilak turned the Ganapati festival into a public (sarvajanik) celebration in 1893 and followed it with the Shivaji festival, first celebrated at Raigad fort in April 1896 after a movement begun in 1895 to repair Shivaji's samadhi (which is why some books give 1895). Both festivals were used to spread nationalist ideas among the masses. Among the other years, 1885 is the founding year of the Congress and 1897 saw Tilak's first sedition trial and the Chapekar brothers' killing of Rand at Poona. Tilak's papers were Kesari (Marathi) and Mahratta (English); Valentine Chirol called him the "Father of Indian Unrest".

Answer: (A) India's four main megacities by superfast railway services

The Diamond Quadrilateral is the proposed high-speed rail network, announced in 2014, to link the four metropolitan cities of Delhi, Mumbai, Chennai and Kolkata; the Mumbai–Ahmedabad bullet-train corridor is the first high-speed line being built. Do not confuse it with the Golden Quadrilateral, the 5,846 km national highway network joining the same four metros (launched in 2001), or with the North–South and East–West road corridors, which cross at Jhansi. Sagarmala is the port-led development programme, Bharatmala covers highways and UDAN covers regional air connectivity.

Answer: (C) Bengal Gazette / Hicky's Gazette / Hicky's Bengal Gazette

The first newspaper in India was the Bengal Gazette or Calcutta General Advertiser, an English weekly started by James Augustus Hicky at Calcutta on 29 January 1780; it was shut down in 1782 for attacking Warren Hastings. Digdarshan (1818) was the first Bengali monthly and Samachar Darpan (1818) the first Bengali weekly newspaper, both brought out by the Serampore missionaries. Parthenon (1830) was a paper of the Hindu College students (Derozians). Other firsts: Sambad Kaumudi (Rammohan Roy, 1821), Bombay Samachar (1822, the oldest surviving paper) and Udant Martand (1826, the first Hindi paper).

Answer: (D) 40

Let the number of correct answers be $x$; then wrong answers $=75-x$, since all questions were attempted. Marks: $2x-(75-x)=45$, so $3x=120$ and $x=40$. Check: $40\times2-35\times1=80-35=45$. Shortcut: if all 75 were right the score would be 150; each wrong answer costs 3 marks (2 lost + 1 deducted), so the number of wrong answers is $(150-45)\div3=35$, leaving 40 right.

Answer: (D) Petroleum, oil and lubricants

Answer as of 2023 — this may have changed since.

Petroleum, oil and lubricants (POL), mainly crude oil, is India's largest import item, making up roughly a quarter or more of the import bill, because India imports over 85% of its crude requirement and is the world's third-largest oil consumer and importer. Electronic goods, gold, machinery (capital goods), coal and chemicals follow. Since 2022–23 Russia has been the largest crude supplier, ahead of Iraq, Saudi Arabia and the UAE. On the export side, the leading items are engineering goods, petroleum products, and gems and jewellery.

Answer: (C) Andhra Pradesh

Answer as of 2023 — this may have changed since.

PSC's final answer key gives Andhra Pradesh (the provisional key had given Gujarat). According to the Annual Survey of Industries, Andhra Pradesh has the largest number of registered food-processing factories in the country (over 5,500 in 2021–22), followed by Tamil Nadu, Telangana, Punjab and Maharashtra. Its strengths are rice milling, seafood and aquaculture, eggs, mango pulp (Chittoor), chillies (Guntur) and edible oil; one of India's first mega food parks, Srini, was set up at Chittoor. Gujarat is better known for dairy processing (Amul, Anand). Central schemes for the sector are PM Kisan SAMPADA Yojana, PMFME and the PLI scheme for food processing.

Answer: (C) Concurrent list

"Economic and social planning" is Entry 20 of the Concurrent List (List III) in the Seventh Schedule, so both Parliament and the State legislatures can make laws on it; if they conflict, the Central law generally prevails (Article 254). At present the Union List has 100 subjects (originally 97), the State List 61 (originally 66) and the Concurrent List 52 (originally 47). The 42nd Amendment (1976) moved five subjects, including education and forests, from the State List to the Concurrent List. There is no "Reserved list" in the Constitution; "reserved" and "transferred" subjects belonged to dyarchy under the Government of India Act, 1919. Residuary powers lie with Parliament (Article 248).

Answer: (B) 52nd amendment

The 52nd Amendment Act, 1985, passed under Rajiv Gandhi's government, added the Tenth Schedule, which disqualifies legislators who defect; the Speaker or Chairman decides such cases, subject to judicial review (Kihoto Hollohan case, 1992). The 91st Amendment (2003) removed the exemption for "splits" and capped the Council of Ministers at 15% of the House. As for the other options, the 51st Amendment (1984) dealt with reserved seats for Scheduled Tribes in some north-eastern States, the 53rd (1986) made special provisions for Mizoram (Article 371G) and the 54th (1986) raised the salaries of Supreme Court and High Court judges.

Answer: (A) 10

${}^nP_4=n(n-1)(n-2)(n-3)=5040$, a product of four consecutive integers. Trying $n=10$: $10\times9\times8\times7=5040$, so $n=10$. Check against the other options: for $n=12$ the product is $12\times11\times10\times9=11880$, already too large, and $n=16$ or $20$ would be larger still. A handy fact is that $5040=7!$, and $7!=10\times9\times8\times7$ because $6\times5\times4\times3\times2=720=10\times9\times8$.

Answer: (C) Krishnadevaraya

Amuktamalyada is a Telugu poem by Krishnadevaraya (1509–29) of the Tuluva dynasty of Vijayanagara; it tells the story of the Tamil saint Andal (Goda Devi) and also sets out his ideas on statecraft. He also wrote the Sanskrit play Jambavati Kalyanam, was called "Andhra Bhoja", and his court had the Ashtadiggajas, eight Telugu poets led by Allasani Peddana. Madhvacharya founded the Dvaita school, Ramanuja the Vishishtadvaita school (Sri Bhashya), and Maladhar Basu wrote the Bengali Sri Krishna Vijaya, for which Sultan Barbak Shah gave him the title Gunaraj Khan.

Answer: (B) expansion of eyeball

In myopia (short-sightedness) the eyeball is elongated from front to back, or the lens is too curved, so light from distant objects is focused in front of the retina; "expansion of eyeball" describes this lengthening. It is corrected with a concave (diverging) lens. In hypermetropia (long-sightedness) the eyeball is too short, the image forms behind the retina and a convex lens is used. Presbyopia is the age-related loss of accommodation (bifocal lens), astigmatism comes from an uneven cornea (cylindrical lens) and cataract is clouding of the lens. The optic nerve has nothing to do with myopia.

Answer: (C) Rajagriha

The First Buddhist Council met at Rajagriha (Sattapanni cave) soon after the Buddha's death, about 483 BCE, under the patronage of Ajatashatru and the presidency of Mahakassapa; Ananda recited the Sutta Pitaka and Upali the Vinaya Pitaka. The Second was at Vaishali (c. 383 BCE, Kalashoka), where the order began to split; the Third at Pataliputra (c. 250 BCE, Ashoka, with Moggaliputta Tissa presiding), where the Abhidhamma Pitaka was compiled; and the Fourth at Kundalvana in Kashmir (Kanishka, with Vasumitra presiding), after which the Hinayana–Mahayana division became clear.

Answer: (C) Lionel Messi

At the BBC Sports Personality of the Year awards in December 2022, the "World Sport Star of the Year" award went to Lionel Messi, who had just led Argentina to the FIFA World Cup title in Qatar (final against France won on penalties; Messi took the Golden Ball and Kylian Mbappé the Golden Boot). The main Sports Personality of the Year award that evening went to the English footballer Beth Mead. Roger Federer and Serena Williams both retired in 2022, and Neeraj Chopra won the Diamond League final that year, but none of them received this award.

Answer: (D) It is the result of an agreement among the federating units.

The Indian federation is not the result of an agreement among the States: Article 1 calls India a "Union of States", and Dr Ambedkar explained that the phrase was chosen because the federation did not arise from a compact and no State has the right to secede. It is a "holding together" federation, unlike the "coming together" federation of the USA. The other three statements are true of India: an independent judiciary, a clear division of powers through three Lists, and unequal representation of States in the Rajya Sabha (by population, unlike the US Senate's two seats for every state). K. C. Wheare therefore called India "quasi-federal".

Answer: (D) Amir Khusru

Amir Khusrau (1253–1325), disciple of the Sufi saint Nizamuddin Auliya, called himself "Tuti-i-Hind", the Parrot of India. He served at the courts of several Delhi Sultans from Balban to Ghiyasuddin Tughlaq, is credited with developing qawwali and associated with the sitar and tabla, and wrote Khazain-ul-Futuh, Tughlaq Nama, Nuh Sipihr and Ashiqa in Persian and Hindavi. Jimutavahana wrote the Dayabhaga (the Bengal school of Hindu inheritance law); Al-Biruni came with Mahmud of Ghazni and wrote Kitab-ul-Hind; and Ibn Battuta, the Moroccan traveller, came in Muhammad bin Tughlaq's reign and wrote the Rihla.

Answer: (A) There was merger between the INC and the National Conference.

PSC's key gives the merger: Surendranath Banerjea's Indian National Conference (which had met at Calcutta in 1883 and 1885 under the Indian Association) merged with the Indian National Congress at the 1886 Calcutta session, making the Congress a truly all-India body. Note that the other two statements are also historically correct — Dadabhai Naoroji presided over the session and Rajendralal Mitra chaired its Reception Committee — which is why many guidebooks answer "All of the above"; the PSC nevertheless kept (A). Later landmarks: Badruddin Tyabji was the first Muslim President (Madras, 1887) and George Yule the first English President (Allahabad, 1888).

Answer: (A) Kolkata – Ghusuri

India's first cotton mill, the Fort Gloster mill, was set up in 1818 on the Hooghly near Kolkata — at Ghusuri (Howrah) according to standard textbooks — but it did not succeed. The first successful modern mill was the Bombay Spinning and Weaving Company, started in 1854 by Cowasji Nanabhai Davar. Ahmedabad's first mill came in 1861 and Jamsetji Tata's Empress Mills at Nagpur in 1877. Nicknames: Ahmedabad is the "Manchester of India", Kanpur the "Manchester of North India" and Coimbatore the "Manchester of South India". For comparison, the first jute mill was at Rishra (1855).

Answer: (B) Belgaum, 1925

PSC cancelled this question in its final answer key and gave one mark to every candidate, because the printed option carries the wrong year. Gandhi presided over the Congress only once, at the Belgaum (now Belagavi, Karnataka) session held in December 1924, not 1925. The provisional key had accepted "Belgaum, 1925" as the intended answer. The other sessions listed: Kakinada 1923 was presided over by Maulana Mohammad Ali, Kanpur 1925 by Sarojini Naidu (the first Indian woman President) and Gauhati 1926 by S. Srinivasa Iyengar. The centenary of the Belgaum session fell in 2024.

Answer: (A) Alauddin Khalji

Alauddin Khalji led the first Muslim expedition into the Deccan when, as governor of Kara, he raided Devagiri (Yadava king Ramachandra) in 1296. As Sultan (1296–1316) he sent Malik Kafur on campaigns between 1307 and 1311 against Devagiri, Warangal (Kakatiyas), Dwarasamudra (Hoysalas) and Madurai (Pandyas). His aim was tribute and wealth rather than annexation. Muhammad bin Tughlaq later annexed the Deccan and shifted his capital to Daulatabad (1327). Balban was occupied with the Mongol frontier, and Firuz Tughlaq undertook no Deccan campaign.

Answer: (A) Ministry of Education

NEAT (National Educational Alliance for Technology) is a public–private partnership of the Ministry of Education, implemented by AICTE, that brings the best ed-tech products on to a single platform; companies offer free seats to students from disadvantaged groups. NEAT 3.0 was launched on 3 January 2022 by Education Minister Dharmendra Pradhan, along with technical textbooks in regional languages. Other Ministry of Education platforms: SWAYAM, DIKSHA, NIPUN Bharat and PM eVIDYA. The ministry was called the Ministry of Human Resource Development until 2020, when the National Education Policy was adopted.

Answer: (B) January 26

International Customs Day is observed every year on 26 January, the day in 1953 on which the Customs Co-operation Council held its first session in Brussels. The body was renamed the World Customs Organization (WCO) in 1994; its headquarters is in Brussels and it has over 180 members. The 2023 theme was "Nurturing the Next Generation: Promoting a Culture of Knowledge-sharing and Professional Pride in Customs". The date coincides with India's Republic Day. Nearby dates: 25 January is National Voters' Day, 27 January is International Holocaust Remembrance Day and 28 January is Data Privacy Day.

Answer: (B) Department of Fin-Tech

The Reserve Bank of India set up a separate Fintech Department with effect from 4 January 2022 by subsuming the Fintech Division of its Department of Payment and Settlement Systems. It deals with innovation in the financial sector, the regulatory sandbox and the Central Bank Digital Currency: the e-rupee pilot began in the wholesale segment on 1 November 2022 and in the retail segment on 1 December 2022. The RBI has no departments named after artificial intelligence, data science or digital currency. Basics: the RBI was established on 1 April 1935, nationalised on 1 January 1949 and has its central office in Mumbai.

Answer: (B) Balban

Balban (1266–87) was the first Sultan to adopt a systematic north-west frontier policy against the Mongols. He built and garrisoned a line of forts (Bhatinda, Sunam, Samana, Dipalpur), placed the frontier under able commanders such as Sher Khan and later his son Prince Muhammad (killed fighting the Mongols in 1285), and kept a strong army at Delhi instead of pursuing new conquests. He is also known for the policy of "blood and iron", breaking the Chahalgani (the Forty) and introducing sijda and paibos. Iltutmish had merely avoided Chengiz Khan by diplomacy; Alauddin Khalji repelled later Mongol raids.

Answer: (D) Kumaragupta I

Nalanda Mahavihara in Bihar was founded in the fifth century by the Gupta ruler Kumaragupta I (c. 415–455), also called Shakraditya. Hiuen Tsang studied there under Shilabhadra in Harsha's time, I-tsing came later, and the Palas were its later patrons; it was destroyed by Bakhtiyar Khalji around 1200 and its ruins became a UNESCO World Heritage Site in 2016. Samudragupta is known from the Allahabad pillar inscription, Chandragupta II from Fa-Hien's visit and Skandagupta for repelling the Hunas. Vikramashila and Odantapuri were founded by the Palas.

Answer: (C) $12\dfrac{1}{2}$ cms

Multiply the ratio $\dfrac{1}{20}:\dfrac{1}{15}:\dfrac{1}{12}$ by 60, the LCM of the denominators, to get $3:4:5$. The sum of the ratio terms is 12 and the perimeter is 30 cm, so one part is $30\div12=2.5$ cm. The sides are therefore 7.5 cm, 10 cm and 12.5 cm, and the longest is $12\dfrac{1}{2}$ cm. Options (A) and (B) are the other two sides. Since $3:4:5$ is a Pythagorean triple, this is a right-angled triangle. Remember that the largest fraction, $\dfrac{1}{12}$, corresponds to the longest side.

Answer: (A) Subhas Chandra Bose

As Congress President (Haripura, 1938), Subhas Chandra Bose set up the National Planning Committee in late 1938 to prepare a plan of economic development based on industrialisation; he appointed Jawaharlal Nehru as its chairman, with K. T. Shah as secretary. So Bose was "instrumental in founding" it, while Nehru headed it. Gandhi favoured village industries and was not enthusiastic about heavy industrialisation. Other pre-independence plans: Visvesvaraya's plan (1934), the Bombay Plan of industrialists (1944), the Gandhian Plan of S. N. Agarwal (1944) and M. N. Roy's People's Plan (1945). The Planning Commission was set up on 15 March 1950.

Answer: (A) Amendment of the Constitution

A Constitution amendment bill (Article 368) must be passed by each House separately with a special majority, and there is no joint sitting to break a deadlock, so the two Houses are exactly equal here. The government can be removed only by the Lok Sabha, to which the Council of Ministers is collectively responsible (Article 75). A money bill can be introduced only in the Lok Sabha, and the Rajya Sabha can merely delay it for 14 days. Creating a new All-India Service is a special power of the Rajya Sabha alone (Article 312). The Houses are also equal in electing and impeaching the President and in removing judges.

Answer: (B) Oranges

The hill slopes of the Eastern Himalaya — Darjeeling and Kalimpong, Sikkim, Arunachal Pradesh and the adjoining north-eastern hills — are known for mandarin oranges, which need a cool, humid climate and well-drained acidic soil. Litchi is a crop of the plains, chiefly Muzaffarpur in Bihar and Malda and Murshidabad in West Bengal. Mango belongs to the plains of Uttar Pradesh, Bihar and Malda, and to the Konkan. The Indian olive (jalpai) grows in the plains of Bengal and Assam. For comparison, Nagpur is called the "Orange City", and the Western Himalaya (Kashmir, Himachal Pradesh) is known for apples.

Answer: (D) Arunachal Pradesh

Article 243D requires seats in panchayats to be reserved for Scheduled Castes and Scheduled Tribes in proportion to their population. Arunachal Pradesh, being wholly tribal, has no Scheduled Castes, so the 83rd Amendment (2000) inserted Article 243M(3A), exempting it from the reservation for Scheduled Castes. The 73rd Amendment (1992) added Part IX and the Eleventh Schedule (29 subjects) and came into force on 24 April 1993, now observed as National Panchayati Raj Day. Part IX as a whole does not apply to Nagaland, Meghalaya and Mizoram. Rajasthan was the first State to introduce Panchayati Raj (Nagaur, 2 October 1959).

Answer: (C) Australia

The India–Australia Economic Cooperation and Trade Agreement (Ind-Aus ECTA) was signed on 2 April 2022 and came into force on 29 December 2022. It was India's first trade agreement with a developed country in about a decade and gives duty-free access to most Indian exports; a fuller Comprehensive Economic Cooperation Agreement is to follow. Do not confuse it with the India–UAE CEPA (signed February 2022, in force from 1 May 2022). India's trade agreement with the United Kingdom was signed only in July 2025, and there is no free-trade agreement with the USA or France (France falls under the India–EU negotiations).

Answer: (C) Magadha

Of the sixteen Mahajanapadas of the sixth century BCE (listed in the Buddhist Anguttara Nikaya), Magadha finally absorbed the rest and became India's first empire under the Haryanka, Shishunaga, Nanda and Maurya dynasties. Its advantages were the iron ores of south Bihar, the fertile Ganga plain, elephants for the army and well-protected capitals (Rajagriha, then Pataliputra). Kashi was annexed by Kosala and Kosala in turn by Magadha under Ajatashatru; Panchala (capitals Ahichchhatra and Kampilya) never rose to imperial status. Avanti and Vatsa were Magadha's other rivals, and Vajji was the best-known republic.

Answer: (C) 20

Total runs $=5\times35=175$. Let E's score be $e$. Then $D=e+5$, $A=e+20$ (E scored 20 fewer than A) and $B=D+E=2e+5$. Since $B+C=75$, the total is $A+(B+C)+D+E=(e+20)+75+(e+5)+e=3e+100=175$, so $e=25$. Hence $D=30$, $A=45$, $B=55$ and $C=75-55=20$. Check: $45+55+20+30+25=175$. Options (A) 45, (B) 55 and (D) 30 are the scores of A, B and D, so make sure you answer for the batsman actually asked.

Answer: (B) Chandragupta Mourya

Chandragupta Maurya (c. 321–297 BCE) overthrew the Nandas with Chanakya's help and built the first empire covering most of the subcontinent, which is why he is called India's first historical emperor. He defeated Seleucus Nikator about 305 BCE, after which Megasthenes came to Pataliputra and wrote the Indica; Greek writers call him Sandrocottus. Jain tradition says he abdicated and died at Shravanabelagola. Dhana Nanda was the last Nanda king whom he replaced; Bimbisara was the Haryanka king of Magadha in the Buddha's time, a king rather than an emperor; Bindusara was Chandragupta's son and Ashoka's father.

Answer: (D) Petroleum refinery and Chemical Fertilizers production

Haldia, at the meeting point of the Haldi and Hooghly rivers in Purba Medinipur, grew up around the Indian Oil refinery (commissioned 1975) and the associated petrochemical and chemical-fertiliser industries, so "petroleum refinery and chemical fertilizers production" is the answer. Batteries are also made there, but that is not one of the two principal industries, and ship repairing is associated with Kolkata (Garden Reach), not Haldia. Related facts: Haldia Dock Complex (1977) is part of the Syama Prasad Mookerjee Port, Kolkata, and National Waterway 1 runs from Prayagraj to Haldia.

Answer: (B) New Delhi

The Delhi government announced a 15-point Winter Action Plan on 30 September 2022 to tackle the seasonal spike in air pollution. It included spraying the Pusa bio-decomposer on farmland to prevent stubble burning, an anti-dust campaign, anti-smog guns, a ban on firecrackers, a "Green War Room", the Green Delhi app and checks on vehicular pollution. Punjab and Haryana are the States associated with stubble burning, but the plan was Delhi's. Related terms: the Graded Response Action Plan (GRAP), enforced by the Commission for Air Quality Management in the NCR, and the National Clean Air Programme (2019).

Answer: (D) W. Wedderburn

The British Committee of the Indian National Congress was set up in London in 1889 to put India's case before the British public and Parliament; Sir William Wedderburn was its chairman and William Digby its secretary, with Dadabhai Naoroji among the members. It published the journal "India" from 1890. Wedderburn was also Congress President twice (Bombay 1889 and Allahabad 1910) and wrote Hume's biography. A. O. Hume founded the Congress and was its general secretary for many years; Naoroji had earlier founded the East India Association in London (1866).

Answer: (D) Gibberellin

Gibberellins (for example gibberellic acid, $GA_3$) break the dormancy of seeds and buds, promote stem elongation and bolting, and trigger the enzyme α-amylase in germinating cereal grains. They were discovered through the "foolish seedling" (bakanae) disease of rice caused by the fungus Gibberella fujikuroi. Dormin is the old name of abscisic acid (ABA), the stress hormone that does the opposite: it induces dormancy and closes stomata. Auxin controls cell elongation, apical dominance and phototropism; cytokinin promotes cell division and delays ageing of leaves. Ethylene, a gas, ripens fruit.

Answer: (A) Vegetative reproduction

Vegetative reproduction, in which a new individual grows from a root, stem or leaf, is confined to plants. Natural examples are the tuber of potato, the rhizome of ginger, the bulb of onion, the runner of grass and the leaf buds of Bryophyllum; cutting, layering, grafting and tissue culture are artificial methods. Asexual reproduction in general also occurs in animals (budding in Hydra, binary fission in Amoeba, regeneration in Planaria), sexual reproduction is found in both kingdoms, and parthenogenesis, the development of an unfertilised egg, is seen mainly in animals such as honeybees (drones), aphids and rotifers.

Answer: (C) Charter Act of 1853

The Charter Act of 1853 separated, for the first time, the legislative and executive functions of the Governor-General's Council by adding six legislative members. This Indian (Central) Legislative Council worked like a mini-Parliament, following the procedures of the British Parliament, which is why the Act is said to have sown the seed of parliamentary government. The same Act opened the civil service to competitive examination and was the last of the Charter Acts. The 1793 Act renewed the charter for 20 years; the 1813 Act ended the Company's trade monopoly except in tea and the China trade and set aside ₹1 lakh for education; the 1833 Act created the Governor-General of India and added a Law Member (Macaulay).

Answer: (B) India

The 13th IBA Women's World Boxing Championships were held in New Delhi from 15 to 26 March 2023; India has hosted the event three times (2006, 2018 and 2023). India topped the medal table with four gold medals: Nitu Ghanghas (48 kg), Nikhat Zareen (50 kg), Lovlina Borgohain (75 kg) and Saweety Boora (81 kg). M. C. Mary Kom holds the record of six women's world titles. The IBA (International Boxing Association, formerly AIBA) is based in Lausanne. The 2023 men's championships were held in Tashkent, Uzbekistan.

Answer: (A) $f(x)$

Replace $x$ by $-x$: $f(-x)=5^{-x}+\dfrac{1}{5^{-x}}+2=\dfrac{1}{5^x}+5^x+2$, which is exactly $f(x)$. A function with $f(-x)=f(x)$ is called an even function, and its graph is symmetric about the y-axis; other examples are $x^2$ and $\cos x$. If $f(-x)=-f(x)$ the function is odd, for example $x^3$ and $\sin x$. Here $f(x)$ can never equal $-f(x)$ because it is always positive, and the options involving $\dfrac{1}{x}$ do not simplify to $f(-x)$.

Answer: (C) Sunday

Three days before Friday is Tuesday, so the 7th is a Tuesday. Dates that differ by a multiple of 7 fall on the same weekday, so the 14th and the 21st are also Tuesdays. The 19th is two days before the 21st, i.e. a Sunday. Alternatively, from the 7th to the 19th is 12 days, which is one week and 5 days, and five days after Tuesday is Sunday. Read "earlier than" carefully: if you count three days after Friday by mistake you start from Monday and get the wrong day.

Answer: (B) 10

Number of protons (atomic number) = mass number − neutrons = $27-14=13$, so the element is aluminium. A neutral atom has 13 electrons; a charge of $+3$ means three electrons have been lost, leaving $13-3=10$. The configuration changes from 2, 8, 3 to 2, 8, so $Al^{3+}$ is isoelectronic with neon and with $Na^+$, $Mg^{2+}$, $F^-$ and $O^{2-}$. Option (A) 13 is the number of protons or of electrons in the neutral atom, and (C) 14 is the number of neutrons. (The booklet prints "change" for "charge".)

Answer: (A) Srirampur

India's first machine paper mill was started at Serampore (Srirampur) in Hooghly district, associated with the Baptist missionaries led by William Carey; textbooks give 1832 (some mention an attempt as early as 1812), and it did not last. The first successful mills came later in the same Hooghly belt: the Royal Bengal Paper Mill at Bally (about 1870) and the Titagarh Paper Mills (1882). Serampore was a Danish settlement and home of the Serampore Mission Press (1800). Bansberia and Budge Budge are jute centres, and Kulti is known for India's first modern ironworks (1870s).

Answer: (B) Above the centre of gravity

The centre of buoyancy is the centre of gravity of the displaced liquid, the point through which the upthrust acts. PSC's answer is that it should be above the centre of gravity, so that a tilt produces a restoring couple; this is exactly true for a fully submerged body such as a submarine or a balloon. For a body floating partly immersed, such as a ship, the precise condition is that the metacentre must lie above the centre of gravity; if the two coincide the equilibrium is neutral, and if the metacentre is below, the body capsizes. Related laws: Archimedes' principle and the law of flotation (a floating body displaces its own weight of liquid). OFFICIAL ANSWER IS A SIMPLIFICATION. PSC's keys give (B) 'Above the centre of gravity', retained as correct_answer. Strictly this holds for fully submerged bodies; for a partly immersed floating body the stability condition is that the metacentre (not the centre of buoyancy) lies above the centre of gravity. Ships are stable with the centre of buoyancy below the centre of gravity.

Answer: (B) Quinary

Economic activities are graded as primary (extraction: farming, mining), secondary (manufacturing), tertiary (ordinary services such as trade and transport), quaternary (knowledge-based services such as IT, research and information) and quinary. Quinary activities are the highest level: top decision-makers and policy-makers such as senior executives, government officials, research scientists and legal and financial consultants, often called "gold-collar" professions. That makes quinary the most modern and developed tier of the service sector. Collar colours: red – primary, blue – secondary, pink – tertiary, white – quaternary, gold – quinary. (The booklet spells quaternary as "Quarternary".)

Answer: (B) Ferozshah Mehta, K. T. Telang and Badruddin Tyabji

Pherozeshah Mehta, K. T. Telang and Badruddin Tyabji, the three lawyers who dominated Bombay's public life and founded the Bombay Presidency Association in 1885, were known as the Bombay Triumvirate or the "Three Stars" of Bombay's public life. Mehta was called the "Lion of Bombay"; Tyabji became the first Muslim President of the Congress (Madras, 1887); Telang became a judge of the Bombay High Court. Tilak, Agarkar and Namjoshi belonged to Poona (New English School, Deccan Education Society). G. H. Deshmukh was "Lokahitawadi", and R. G. Bhandarkar was an orientalist and Prarthana Samaj leader. The extremist trio was Lal-Bal-Pal.

Answer: (D) 1818

The first cotton mill in India, the Fort Gloster mill near Kolkata, was set up in 1818 but failed. The first successful mill was the Bombay Spinning and Weaving Company (1854, C. N. Davar). Dates of other industrial firsts: railway, Bombay to Thane, 1853; jute mill, Rishra, 1855; modern ironworks, Kulti, 1870s; Tata Iron and Steel Company, Jamshedpur, 1907. The years 1812, 1820 and 1840 have no connection with cotton mills and are plain distractors. Note that the same paper also asks the place of this mill (Ghusuri).

Answer: (A) Purushpur

Kanishka, the greatest Kushana ruler, had his capital at Purushapura (modern Peshawar), with Mathura as a second capital. His accession was traditionally dated to 78 CE, the start of the Saka era. He convened the Fourth Buddhist Council at Kundalvana in Kashmir (some traditions place it at Jalandhar), patronised Mahayana Buddhism, and had Ashvaghosha, Nagarjuna, Vasumitra and the physician Charaka at his court. The Gandhara and Mathura schools of art flourished under him and he controlled part of the Silk Route. Pataliputra was the capital of the Mauryas and the Guptas.

Answer: (C) Ehrar League

The Ahrar movement arose among young nationalist Muslims such as Maulana Mohammad Ali, Hakim Ajmal Khan, Hasan Imam, Mazhar-ul-Haq and Zafar Ali Khan, who disliked the loyalist politics of the Aligarh school and urged Muslims to take part in the national movement alongside the Congress. (The organised party Majlis-i-Ahrar-ul-Islam was formed later, in 1929.) The Muslim League (1906) began as a loyalist body, though it too reached the Lucknow Pact with the Congress in 1916. The Ahmadiyya movement (1889, Mirza Ghulam Ahmad of Qadian) was a religious reform sect, and the Deoband school (1866) was an orthodox revivalist seminary, anti-British but primarily religious.

Answer: (B) the inhuman transportation and hanging of Indian youth.

Madan Lal Dhingra, a student associated with India House in London (Shyamji Krishnavarma, V. D. Savarkar), shot Sir William Curzon Wyllie, political aide-de-camp to the Secretary of State for India, on 1 July 1909. In his statement he said he had avenged the inhuman hangings and transportations of patriotic Indian youths, such as the execution of Khudiram Bose (1908). He was hanged at Pentonville prison on 17 August 1909. The arrests of the Ghadarites came later (1915), Lal-Bal-Pal were not imprisoned together, and the Partition of Bengal was not the motive he gave.

Answer: (C) (C, E)

Number the six seats 1 to 6 round the table. Put B at seat 1; A sits opposite at seat 4. B is between C and D, so C and D occupy seats 2 and 6; A is between E and F, so E and F occupy seats 3 and 5. E is next to D (to D's left), so if D is at seat 2, E is at seat 3, which leaves F at seat 5 and C at seat 6. Opposite pairs in a hexagon are 1–4, 2–5 and 3–6, i.e. A–B, D–F and C–E. Hence C and E face each other. The mirror arrangement (D at 6, E at 5) gives the same opposite pairs.

Answer: (A) elected by Provincial Assemblies

Under the Cabinet Mission Plan (1946) the Constituent Assembly had 389 seats: 296 for British India and 93 for the princely states. The British Indian members were elected indirectly by the members of the provincial legislative assemblies through proportional representation by single transferable vote, and the states' representatives were nominated by their rulers. So the members were not directly elected by the people, not nominated by the British government, and not drawn only from the princely states. The Assembly first met on 9 December 1946; Dr Rajendra Prasad was its President and Dr Ambedkar chaired the Drafting Committee. After Partition its strength fell to 299.

Answer: (C) First

Answer as of 2023 — this may have changed since.

India Post runs the largest postal network in the world, with over 1.5 lakh post offices, about 90% of them in rural areas, so India ranks first. The modern postal system dates from 1854 under Lord Dalhousie; the six-digit PIN code was introduced in 1972, Speed Post in 1986 and the India Post Payments Bank in 2018. The world's highest post office is at Hikkim in Himachal Pradesh. The Post Office Act, 2023 has replaced the Indian Post Office Act of 1898. The Universal Postal Union has its headquarters at Bern.

Answer: (D) Haji Shariyatullah

The Faraizi movement was started around 1818 by Haji Shariatullah of Faridpur in eastern Bengal; it called on Muslims to perform their obligatory religious duties ("faraiz") and give up un-Islamic practices. Under his son Dudu Miyan it became an agrarian movement of the peasantry against zamindars and indigo planters. Titumir (Mir Nisar Ali) led a separate rising at Narkelberia near Barasat and built the famous bamboo fort (1831). Kunwar Singh of Jagdishpur was a leader of the 1857 revolt in Bihar, and Digambar Biswas, with Bishnu Charan Biswas, led the Indigo Revolt of 1859–60 in Nadia.

Answer: (C) Huna king

Mihirakula (c. 515–540 CE), son of Toramana, was the most notorious Huna (White Hun or Hephthalite) ruler in India, with his capital at Sakala (Sialkot). A Shaiva, he is described by Hiuen Tsang as a persecutor of Buddhists. He was defeated by Yashodharman of Malwa (Mandasor inscription) and by the Gupta ruler Narasimhagupta Baladitya, and retired to Kashmir. Earlier, Skandagupta had repelled the first Huna invasion. Famous names from the other groups: Rudradaman I among the Shakas, Kanishka among the Kushanas and Gondophernes among the Pahlavas (Indo-Parthians).

Answer: (A) Justice G. Rohini

The Commission to examine sub-categorisation of Other Backward Classes in the Central list was constituted under Article 340 on 2 October 2017 and headed by Justice (Retd.) G. Rohini, the first woman Chief Justice of the Delhi High Court. After several extensions it submitted its report to the President on 31 July 2023. Its job was to see whether the benefits of the 27% OBC reservation are unevenly distributed among castes. Justice U. U. Lalit was the 49th and Justice D. Y. Chandrachud the 50th Chief Justice of India. Earlier backward-class commissions were those of Kaka Kalelkar (1953) and B. P. Mandal (1979).

Answer: (A) Silver

The Silver Revolution refers to the rapid growth in egg and poultry production in India from about 1969 to 1978. The Golden Revolution relates to horticulture and honey, the White Revolution to milk (Operation Flood, 1970, Dr Verghese Kurien), and "Liquid" is not a recognised revolution. Others to remember: Green – food grains, Blue – fish, Yellow – oilseeds, Pink – prawns and onions, Red – meat and tomato, Grey – fertilisers, Black – petroleum, Brown – leather and cocoa, Round – potato. Andhra Pradesh is India's largest egg-producing State.

Answer: (D) All the reasons above

India is the world's largest milk producer, yet its output of processed dairy products such as cheese, butter and milk powder is comparatively small, and all three stated reasons contribute. Most milk is consumed in liquid form because demand for fresh milk is high; the purchasing power of most people for costlier value-added products is low; and the milk yield per animal is far below the world average because much of the cattle is underfed and of poor breed ("lean"). Related facts: Operation Flood (1970), NDDB at Anand, National Milk Day on 26 November (Dr Kurien's birthday) and Uttar Pradesh as the top milk-producing State.

Answer: (B) Cotton

Cotton is India's principal fibre crop and the base of its largest organised industry, cotton textiles; India has the largest area under cotton in the world and is among the top producers. It is a kharif crop that grows best on the black regur soil of the Deccan, with Gujarat, Maharashtra and Telangana as the leading States; Bt cotton (2002) is the only genetically modified crop approved for commercial cultivation in India. Jute, the "golden fibre", is important mainly in West Bengal, Bihar and Assam and is used for sacking. Flax yields linen and is a minor crop, and til (sesame) is an oilseed, not a fibre.

Answer: (B) the Consolidated Fund of India.

Article 266(1) says that all revenues received by the Government of India, all loans raised by it and all money received in repayment of loans form the Consolidated Fund of India. All other public money received by the government, such as provident fund deposits and small savings, goes into the Public Account (Article 266(2)). The Contingency Fund (Article 267) is an imprest at the President's disposal for unforeseen expenditure. Every State likewise has its own Consolidated Fund, Public Account and Contingency Fund, and the accounts are audited by the Comptroller and Auditor General.

Answer: (C) sodium hydrogen carbonate and tartaric acid

PSC's answer is sodium hydrogen carbonate with tartaric acid. Strictly, that mixture is baking powder; baking soda by itself is just sodium hydrogen carbonate, $NaHCO_3$. When the powder is heated or moistened, the acid reacts with the hydrogen carbonate to release carbon dioxide, which makes cakes and bread rise, and the tartaric acid also neutralises the sodium carbonate that would otherwise leave a bitter taste. Options with sodium carbonate (washing soda is $Na_2CO_3\cdot10H_2O$) or acetic acid (vinegar) are wrong. $NaHCO_3$ is also an antacid and is used in soda-acid fire extinguishers; tartaric acid occurs in tamarind and grapes. Strictly, sodium hydrogen carbonate + tartaric acid is BAKING POWDER; baking soda is sodium hydrogen carbonate alone (NCERT Class X usage).

Answer: (B) Its volume increases.

Thermal expansion works like a photographic enlargement: every linear dimension of the body grows in the same proportion, including the dimensions of a cavity or hole. The cavity therefore expands exactly as if it were filled with the same metal, and its volume increases by $\Delta V=\gamma V\Delta T$, whatever the metal. This is why a hole in a metal plate gets bigger on heating, an iron tyre is heated before being fitted on a cart wheel, and a tight metal lid loosens under hot water. The coefficients are related as $\alpha:\beta:\gamma=1:2:3$.

Answer: (A) Satakarni I

The Nanaghat (Naneghat) cave inscription in the Western Ghats near Pune was issued by Queen Naganika (Nayanika), widow of the Satavahana king Satakarni I. It lists his Vedic sacrifices, including two Ashvamedhas, and calls him lord of Dakshinapatha. The achievements of Gautamiputra Satakarni are recorded in the Nasik prashasti of his mother Gautami Balashri; Vasishthiputra Pulumavi was his son, and Yajna Sri Satakarni, known for ship-type coins, was the last great Satavahana. The dynasty was founded by Simuka, had its capital at Pratishthana (Paithan) and used matronymics.

Answer: (B) UNEP (United Nations Environment Programme)

The Adaptation Gap Report is an annual publication of the United Nations Environment Programme (UNEP). The 2022 edition, titled "Too Little, Too Slow: Climate adaptation failure puts world at risk", came out in November 2022 just before COP27 at Sharm el-Sheikh and warned that adaptation finance for developing countries is five to ten times below what is needed. UNEP, founded in 1972 after the Stockholm Conference, has its headquarters at Nairobi and also issues the Emissions Gap Report. The WEF publishes the Global Risks and Global Gender Gap reports, NITI Aayog brings out the SDG India Index, and the World Social Forum is a civil-society gathering that publishes no such report.

Answer: (B) Scotland

The Scottish Parliament passed the Gender Recognition Reform (Scotland) Bill on 22 December 2022. It sought to let people change their legal gender by self-declaration, dropping the need for a medical diagnosis of gender dysphoria, lowering the minimum age from 18 to 16 and shortening the waiting period. In January 2023 the UK government blocked it from becoming law by using Section 35 of the Scotland Act, 1998, for the first time ever. Nicola Sturgeon was Scotland's First Minister at the time. In England the UK-wide Gender Recognition Act, 2004 continues to apply, and Switzerland had already introduced self-declaration from January 2022.

Answer: (B) Liberal

Dadabhai Naoroji was elected to the House of Commons in 1892 from Central Finsbury, London, as a Liberal Party candidate, by a wafer-thin majority; he was the first Indian member of the British Parliament. Known as the "Grand Old Man of India", he set out the drain theory in "Poverty and Un-British Rule in India" and was Congress President three times (1886, 1893 and 1906). The second Indian MP, Mancherjee Bhownaggree (1895), was a Conservative, and the third, Shapurji Saklatvala (1922), was elected with Labour support and later as a Communist. The Labour Party itself was formed only in 1900.

Answer: (A) Rasbehari Bose

On 23 December 1912 a bomb was thrown at Lord Hardinge as he rode an elephant through Chandni Chowk on his state entry into the new capital, Delhi. The plot (the Delhi or Delhi–Lahore Conspiracy Case) was masterminded by Rash Behari Bose; Basanta Kumar Biswas, Amir Chand, Avadh Behari and Bal Mukund were executed for it. Rash Behari escaped to Japan in 1915, later founded the Indian Independence League and handed over the INA to Subhas Bose. Sachindranath Sanyal was his associate and later a founder of the Hindustan Republican Association; Bhai Parmanand was tried in the Lahore Conspiracy Case; Sohan Lal Pathak was a Ghadarite hanged in Burma.

Answer: (A) Mother-in-law

X is the wife of Z, and P is the mother of X, so P is the mother of Z's wife, i.e. Z's mother-in-law. The details about Y (P's brother) and Q (P's husband) are extra information put in to distract; they would make Y the maternal uncle of X, and Q the father of X and father-in-law of Z. In blood-relation questions, pick out only the links that connect the two persons asked about, and draw a small family tree if needed.

Answer: (D) Loss

To rectify is to set right a mistake; in the same way, to regain is to get back what was lost, i.e. to make good a loss. In both pairs the first word is an action that undoes or remedies the second. "Make", "find" and "realise" are verbs, not conditions that regaining puts right, so they do not complete the analogy. Similar pairs: cure – disease, repair – damage, quench – thirst, recover – loss.

Answer: (C) Suprarenal gland

The suprarenal gland is another name for the adrenal gland, which sits on top of each kidney, and it is the source of all the other three. Its outer cortex secretes glucocorticoids (such as cortisol, which regulates glucose metabolism and suppresses inflammation), mineralocorticoids (such as aldosterone, which controls sodium, potassium and water balance) and small amounts of sex hormones. Its inner medulla secretes adrenaline and noradrenaline, the "fight or flight" emergency hormones. Disorders: Addison's disease from under-secretion of cortical hormones and Cushing's syndrome from excess cortisol.

Answer: (C) Goods and Services Tax

Among the four taxes listed, Goods and Services Tax brought the Centre the most revenue in 2022–23: roughly ₹8.5 lakh crore, narrowly ahead of corporation tax and personal income tax (about ₹8.3 lakh crore each), with customs far behind at about ₹2.1 lakh crore. In the Budget's "Rupee Comes From" chart for 2022–23, borrowings supplied 35 paise, GST 16, corporation tax 15, income tax 15, excise 7 and customs 5. GST was introduced on 1 July 2017 by the 101st Amendment, and the GST Council is set up under Article 279A. In the years after 2022–23 personal income tax has overtaken both GST and corporation tax.

Answer: (C) Kalidasa

Kumarasambhavam ("Birth of Kumara") is a Sanskrit mahakavya by Kalidasa on the marriage of Shiva and Parvati and the birth of their son Kartikeya, who was to slay the demon Taraka. Kalidasa's other works are the epic Raghuvamsham, the lyric poems Meghadutam and Ritusamharam, and the plays Abhijnanashakuntalam, Malavikagnimitram and Vikramorvashiyam; he is associated with the court of Chandragupta II Vikramaditya. Vishnu Sharma wrote the Panchatantra, Dandin the Dashakumaracharita and Kavyadarsha, and Somadeva the Kathasaritsagara.

Answer: (C) Russia

The BMPT "Terminator" (Boyevaya Mashina Podderzhki Tankov, i.e. tank support fighting vehicle) is a Russian armoured vehicle built by Uralvagonzavod on a T-72/T-90 tank chassis. It carries twin 30 mm autocannon, Ataka anti-tank missiles and grenade launchers, and is designed to protect tanks from infantry in urban combat; it was in the news when Russia deployed it in the Ukraine war in 2022. Other well-known systems: Russia's T-14 Armata and S-400, Israel's Merkava tank and Iron Dome, the US M1 Abrams, China's Type 99, and India's Arjun tank.

Answer: (D) 12

Follow the cards step by step, starting with 10 each. E borrows 3 from A: A = 7, E = 13. E gives 5 to C: E = 8, C = 15. C gives 4 to B: C = 11, B = 14. B passes 2 to D: B = 12, D = 12. So D has 12 cards. Final tally: A 7, B 12, C 11, D 12, E 8, which adds up to 50, the same as the starting total — a useful check. D takes part in only one transaction, receiving 2 cards, so $10+2=12$ can be read off directly.

Answer: (A) $W_1 > W_2$

The cage is made of wire, so it is open to the air. While the bird sits on its perch, its weight is carried by the cage and the balance reads cage plus bird ($W_1$). When it flies, its weight is supported by the air; the downward push it gives the air passes out through the open wires instead of pressing on the floor of the cage, so the balance reads less: $W_1>W_2$. If the bird were in a sealed, airtight box, the air inside would pass the bird's weight on to the box, and the average reading would not change ($W_1=W_2$). This open-cage versus closed-box contrast is a favourite exam trap.

Answer: (C) Nepal

Nepal's Parliament passed the country's first Citizenship Amendment Bill, amending the Citizenship Act of 2006, in July 2022 after more than two years of debate. President Bidya Devi Bhandari declined to authenticate it, and it finally became law when President Ram Chandra Paudel signed it on 31 May 2023. It gives citizenship by descent to children of those who had obtained citizenship by birth, and eases the rules for children of Nepali mothers. Do not confuse it with India's own Citizenship (Amendment) Act, 2019, whose rules were notified in March 2024.

Answer: (C) Nabagopal Mitra

Nabagopal Mitra (1840–94) organised the Hindu Mela (1867) with the support of the Tagore family and founded the National Paper, the National Society, the National School and the National Gymnasium, among other "National" institutions, which earned him the nickname "National Mitra". Rajnarayan Bose, whose ideas inspired the Mela, is called the "Grandfather of Indian Nationalism". Satyendranath Tagore was the first Indian to enter the Indian Civil Service (1863) and wrote a patriotic song for the Mela; Jyotirindranath Tagore was a dramatist and composer who was also associated with it.

Answer: (A) the ratio between the total population and the actual utilization of land in a country.

The man–land ratio relates a country's total population to its effective land, meaning the land actually usable and productive along with its resources. It is thus a qualitative measure of the pressure of population on resources. Population density, by contrast, is simply the number of people divided by total area, a purely quantitative measure; option (B), comparing total land with total population, describes density, not the man–land ratio. Options (C) and (D) restrict the comparison to adults or males and are meaningless. Census 2011 figures: India's density 382 per sq km; Bihar highest among States (1,106), West Bengal second (1,028) and Arunachal Pradesh lowest (17).

Answer: (A) Babur and Ibrahim Lodi

The First Battle of Panipat (21 April 1526) was fought between Babur and Ibrahim Lodi; Babur's artillery and the tulughma flanking tactic won the day, ending the Delhi Sultanate and founding Mughal rule. Babur then defeated Rana Sanga of Mewar at Khanwa (1527), Medini Rai at Chanderi (1528) and the Afghans at Ghaghra (1529). Sher Khan (Sher Shah) fought Humayun, not Babur, at Chausa (1539) and Kannauj (1540). Akbar and Hemu fought the Second Battle of Panipat (1556), and the Third (1761) was between Ahmad Shah Abdali and the Marathas.

Answer: (A) Ballarpur

Ballarpur in Chandrapur district of Maharashtra, home of Ballarpur Industries Ltd (BILT), is regarded as the largest centre of the paper industry in India, using bamboo from the nearby forests. Nepanagar in Madhya Pradesh has the NEPA Mills, India's first newsprint factory. Salkia is an industrial locality of Howrah, and Nagpur is known for oranges rather than paper. Other paper centres worth remembering: Titagarh, Naihati and Raniganj (West Bengal), Sirpur-Kaghaznagar (Telangana), Rajahmundry (Andhra Pradesh), Dandeli (Karnataka) and the Security Paper Mill at Narmadapuram (Hoshangabad), which makes currency paper.

Answer: (C) Sikandar Shah

The Adina Mosque at Pandua (Malda district) was built by Sultan Sikandar Shah (1358–90) of the Ilyas Shahi dynasty, in the years around 1370, and was then the largest mosque in the subcontinent. Pandua was the capital of the Bengal Sultanate before Gaur. Alauddin Husain Shah (1493–1519) is known for his patronage of Bengali literature and for monuments at Gaur such as the Chhota Sona Masjid of his reign; Firuz Shah Tughlaq twice invaded Bengal but failed to subdue it, the second time against Sikandar Shah himself; and Zain-ul-Abidin was the tolerant "Budshah" of Kashmir.

Answer: (C) 40%

Carnot efficiency is $\eta=1-\dfrac{T_2}{T_1}$, with temperatures in kelvin. Here $T_1=227+273=500$ K and $T_2=27+273=300$ K, so $\eta=1-\dfrac{300}{500}=0.4$, i.e. 40%. The usual mistake is to use Celsius values, which gives a meaningless 88%. No heat engine can be 100% efficient, since that would need the sink to be at absolute zero (second law of thermodynamics), and the Carnot value is the upper limit for any engine working between the same two temperatures.

Answer: (B) S

Interphase has three sub-stages. In $G_1$ the cell grows and makes RNA and proteins; in the S (synthesis) phase DNA replicates, so the amount of DNA doubles (2C to 4C) while the chromosome number stays the same; in $G_2$ the cell prepares for division. $G_0$ is the resting or quiescent stage of cells that have stopped dividing, such as nerve cells, and is not a DNA-synthesis stage. Interphase takes up over 95% of the cell cycle and is followed by the M phase (mitosis and cytokinesis).

Answer: (D) 1961 - 1981

India's population history is usually divided into four phases: 1901–21, stagnant growth (1921 is the "Year of the Great Divide", after the only decade with negative growth); 1921–51, steady growth; 1951–81, population explosion, when death rates fell quickly but birth rates stayed high; and after 1981, high growth with definite signs of slowing. Decadal growth peaked at 24.8% in 1961–71 and was 24.66% in 1971–81, so among the given options 1961–1981 is the period of explosion. Census 2011 recorded 121.08 crore people and decadal growth of 17.7%.

Answer: (D) Sir Syed Ahmed Khan

Sir Syed Ahmad Khan founded the Muhammadan Anglo-Oriental School at Aligarh in 1875; it became a college in 1877 and Aligarh Muslim University in 1920. It was the centre of the Aligarh Movement, which urged Muslims to take to modern Western education. He also founded the Scientific Society (1864) and the journal Tahzib-ul-Akhlaq. Nawab Salimullah of Dacca hosted the founding session of the Muslim League in 1906; Liaquat Ali Khan became the first Prime Minister of Pakistan; and Khan Abdul Ghaffar Khan, the "Frontier Gandhi", founded the Khudai Khidmatgar (Red Shirts).

Answer: (D) Grants

A capital receipt either creates a liability or reduces an asset. Provident fund deposits create a liability for the government, while recovery of loans and disinvestment of PSU shares reduce its assets; all three are capital receipts (the last two being non-debt capital receipts). Grants received create no liability and reduce no asset, so they are revenue receipts, classed with non-tax revenue such as interest, dividends and fees. Related definitions: fiscal deficit = total expenditure − (revenue receipts + non-debt capital receipts); primary deficit = fiscal deficit − interest payments.

Answer: (B) $2n$

The molar mass of water is 18 g, so 9 g of water is 0.5 mole and contains $n$ molecules. The molar mass of carbon dioxide is $12+2\times16=44$ g, so 44 g is 1 mole, which contains twice as many molecules as half a mole, i.e. $2n$. Equal numbers of moles, not equal masses, contain equal numbers of molecules. One mole of any substance has $6.022\times10^{23}$ particles (Avogadro's number), and one mole of any gas occupies 22.4 litres at STP.

Answer: (B) Magnesium

Newlands (1865) arranged the elements in order of increasing atomic mass and found that every eighth element resembled the first, like the eighth note of a musical octave. His rows ran Li, Be, B, C, N, O, F and then Na, Mg, Al, Si, P, S, Cl, so beryllium falls with magnesium (and lithium with sodium). Calcium comes one octave further on, aluminium is beryllium's diagonal relative in the modern table and sodium pairs with lithium. The law held only up to calcium. Timeline: Dobereiner's triads (1817), Newlands' octaves (1865), Mendeleev's table (1869) and Moseley's modern periodic law based on atomic number (1913).

Answer: (B) Neeraj Chopra

Switzerland Tourism named Olympic champion Neeraj Chopra its "Friendship Ambassador" in 2022, to showcase the country's outdoor and adventure destinations to Indian travellers. Neeraj Chopra won the javelin gold at the Tokyo Olympics (87.58 m), India's first Olympic gold in athletics, followed by the Diamond League title in 2022, the World Championship gold in 2023 and the silver at the Paris Olympics in 2024. P. V. Sindhu (badminton), Mary Kom (boxing) and Virat Kohli (cricket) have no such role; the actor Ranveer Singh had earlier been Switzerland Tourism's brand ambassador for India.

Answer: (C) D

List each girl's games from the two statements in which she appears. A: football, volleyball, badminton. B: football, volleyball, cricket. C: cricket, football, badminton. D: badminton, cricket, volleyball. Only D plays badminton, cricket and volleyball, and D is option (C). A quicker way: the girl wanted does not play football, and the only two statements that leave out football are "C and D play badminton and cricket" and "D and A play volleyball and badminton"; D is common to both. (In the booklet the girls' names carry a bar over the letter.)

Answer: (C) Madhya Pradesh

Madhya Pradesh declared Mallakhamb its State sport in 2013. Mallakhamb ("malla" = wrestler, "khamb" = pole) is a traditional Indian sport in which gymnasts perform yoga-like postures and aerial feats on a vertical wooden pole, a hanging pole or a rope; it was revived in the Maratha period, and Ujjain in Madhya Pradesh is a major centre. It was demonstrated at the 1936 Berlin Olympics and is part of the Khelo India Youth Games. Kerala is associated with Kalaripayattu, while Assam and Rajasthan have no link with Mallakhamb.

Answer: (B) 1, 2 and 4

The capital account of the Balance of Payments records transactions that change a country's foreign assets and liabilities: foreign investment (both FDI and portfolio investment), loans (external assistance and commercial borrowings) and banking capital such as NRI deposits. Remittances from abroad are private transfers and belong to the current account, under "invisibles", along with trade in services and investment income. So items 1, 2 and 4 are correct and 3 is not. India is the world's largest recipient of remittances; the rupee is fully convertible on the current account (since 1994) but only partially on the capital account.

Answer: (D) Art. 24

Article 24 prohibits the employment of children below 14 years in any factory or mine or in any other hazardous employment, and it deals specifically with children. Article 23 prohibits traffic in human beings, begar and other forced labour for everyone; the two together form the Right against Exploitation. Article 17 abolishes untouchability and Article 19 guarantees the six freedoms. Other provisions on children: Article 21A (free and compulsory education from 6 to 14), Article 39(e) and (f), Article 45 and Article 51A(k). The Child Labour (Prohibition and Regulation) Act, 1986 was strengthened in 2016.

Answer: (A) UNDP (United Nations Development Programme)

The North Eastern Region District SDG Index and Dashboard 2021–22 was released on 26 August 2021 by NITI Aayog and the Ministry of Development of North Eastern Region, with technical support from the UNDP. It was the first district-level SDG index for a region in India and ranked districts of the eight north-eastern States; East Sikkim came first. NITI Aayog's national SDG India Index has been published since 2018. The UNDP (headquarters New York) also brings out the Human Development Report. The World Bank, the Asian Development Bank (Manila) and the IMF were not partners in this index.

Answer: (A) The Ilbert Bill Controversy

The Ilbert Bill (1883), drafted by Law Member C. P. Ilbert under Lord Ripon, proposed to let Indian district magistrates and sessions judges try European accused. The European community reacted with a furious, openly racist agitation (the "White Mutiny"), and the Bill was diluted in 1884 so that a European could demand a jury of which half were Europeans. The episode exposed racial arrogance as nothing else had, and taught Indians the value of organised agitation, hastening the birth of the Congress in 1885. The other three were Lord Lytton's measures: the Vernacular Press Act (1878), the Arms Act (1878) and the lowering of the ICS age limit from 21 to 19.

Answer: (D) 9

Write the two numbers around their mean, 8795: $8798\times8792=(8795+3)(8795-3)=8795^2-3^2=8795^2-9$. Adding 9 gives $8795^2$, a perfect square, and 9 is the least such number, because the product lies just below $8795^2$ and far above the previous square $8794^2$ (which is $2\times8795-1=17589$ less than $8795^2$). In general, for two numbers that differ by $2k$, the product falls short of the square of their mean by $k^2$.

Answer: (D) volume

For a temperature rise $\Delta T$, the fractional increase in length (or diameter) is $\alpha\Delta T$, in surface area $2\alpha\Delta T$ and in volume $3\alpha\Delta T$, because area depends on the square and volume on the cube of the linear dimension. The percentage increases are therefore in the ratio 1 : 2 : 3, and volume changes the most. Density does not increase at all: the mass is unchanged while the volume grows, so density falls by about $3\alpha\Delta T$. For iron, $\alpha$ is about $1.2\times10^{-5}$ per °C.

Answer: (C) Manufacturing, construction, electricity, gas and water supply

Answer as of 2023 — this may have changed since.

The National Statistical Office reports Gross Value Added under broad industry groups. Over the last decade the industry group — manufacturing (about 17–18%), construction (about 8%) and electricity, gas and water supply (about 2–3%) — together contributed roughly 27–28% of real GVA at basic prices, more than any other single group listed. Financial, real estate and professional services came next (about 21–22%), followed by trade, hotels, transport and communication (about 18–19%) and public administration, defence and other services (about 12–13%). Agriculture accounts for about 15%. GVA at basic prices plus net taxes on products equals GDP; the base year of the series was 2011–12.

Answer: (C) The Government of India Act, 1919

The Government of India Act, 1919 provided for a Public Service Commission; following the Lee Commission's recommendation (1924) it was set up on 1 October 1926 with Sir Ross Barker as chairman. The Government of India Act, 1935 then provided for a Federal Public Service Commission and Provincial Public Service Commissions, and under the Constitution the Federal PSC became the UPSC (Articles 315–323). The Indian Councils Act, 1892 introduced indirect election and discussion of the budget, and the Act of 1909 (Morley–Minto) introduced separate electorates for Muslims. (The booklet misprints the year in option A as 1982.)

Answer: (B) Jorhat

The Tocklai Tea Research Institute at Jorhat, established in 1911, is the oldest and largest tea research station of its kind in the world. Assam produces more than half of India's tea; the industry began after wild tea was noticed in Assam in 1823, and the Assam Company was formed in 1839. Guwahati has a tea auction centre, Digboi has India's oldest oil refinery (1901) and Tezpur is a town on the north bank of the Brahmaputra. The Tea Board of India has its head office in Kolkata, and a Darjeeling tea research centre is located at Kurseong.

Answer: (A) Green bonds

Green bonds are debt instruments whose proceeds are earmarked for environmentally sustainable projects such as renewable energy, clean transport and energy efficiency. The first was issued by the European Investment Bank in 2007 and the World Bank followed in 2008; in India, Yes Bank issued the first green bond in 2015, and the Government of India issued its first Sovereign Green Bonds worth ₹16,000 crore in January–February 2023. "Nature", "low emission" and "environment" bonds are not standard terms. Related instruments: blue bonds for ocean projects, social bonds, and masala bonds (rupee-denominated bonds issued abroad).

Answer: (D) Ujjayini

Chandragupta II Vikramaditya (c. 375–415) conquered the Shaka (Western Kshatrapa) kingdom of Malwa, Gujarat and Saurashtra, took the title Shakari, and made Ujjayini (Ujjain) his second capital alongside Pataliputra; this gave the Guptas access to the western ports such as Bharuch. Fa-Hien visited India in his reign, and the Mehrauli iron pillar is attributed to him. Vidisha (Besnagar) is known for the Heliodorus pillar, Malava is the name of the region around Ujjain rather than a city, and Valabhi was the later capital of the Maitrakas of Saurashtra.

Answer: (C) Home Rule movement

According to standard textbooks, Tilak came to be called "Lokmanya" ("revered by the people") during the Home Rule movement. He started his Home Rule League in April 1916, covering Maharashtra (except Bombay city), Karnataka, the Central Provinces and Berar; Annie Besant started hers in September 1916 for the rest of India. Some biographies trace the title to his first sedition trial of 1897, but the Commission follows the textbook view. The Swadeshi movement (1905–08) and his 1908 trial, after which he spent six years in Mandalay and wrote the Gita Rahasya, came earlier.

Answer: (C) Lahore

The Nehru Report (August 1928), drafted by a committee under Motilal Nehru in answer to the all-white Simon Commission, asked for dominion status, joint electorates and fundamental rights. At the Calcutta session (December 1928) the Congress accepted it but gave the government one year to concede dominion status. When nothing came of it, the Lahore session of December 1929, presided over by Jawaharlal Nehru, declared the Report to have lapsed and adopted Purna Swaraj as the goal, fixing 26 January 1930 as Independence Day. The Madras session (1927) had resolved to boycott the Simon Commission, and the Bombay session came in 1934.

Answer: (B) Thalassemia

Thalassemia is an autosomal recessive disorder: the defective globin genes lie on chromosome 16 (alpha) or chromosome 11 (beta), not on the sex chromosomes, so both sexes are equally affected. Haemophilia and red–green colour blindness are sex-linked (X-linked recessive) disorders, far more common in males, with females usually acting as carriers. Other autosomal disorders are sickle-cell anaemia, phenylketonuria and cystic fibrosis. Chromosomal disorders are a separate group: Down syndrome (trisomy 21), Turner syndrome (XO) and Klinefelter syndrome (XXY). World Thalassemia Day is 8 May.

Answer: (B) W.G. Rosen

The word "biodiversity" was coined by Walter G. Rosen in 1985 while planning the National Forum on BioDiversity held in Washington in 1986; it was popularised by E. O. Wilson, who is often called the "father of biodiversity". A. G. Tansley coined the term "ecosystem" (1935), Eugene Odum is regarded as the father of modern ecology, and Ernst Mayr gave the biological species concept. Also remember: Ernst Haeckel coined "ecology", Norman Myers gave the idea of biodiversity hotspots, India has four hotspots, and 22 May is the International Day for Biological Diversity.

Answer: (B) C

Tall: A, D, E, so the short girls are B and C. Dark: B, D, E, so the fair girls are A and C. Fat: C and E, so the thin girls are A, B and D. The girl who is short and fair and fat must be in all three lists: short (B, C), fair (A, C) and fat (C, E). Only C is common, so the girl at the first desk is C, option (B). For reference, the full descriptions are: A – tall, fair, thin; B – short, dark, thin; C – short, fair, fat; D – tall, dark, thin; E – tall, dark, fat.

Answer: (C) $3.00 \times 10^{-4}\ ^\circ C^{-1}$

Mass is constant, so density falls as volume grows: $\rho_{20}=\rho_{40}(1+\gamma\Delta T)$. Hence $\gamma=\dfrac{\rho_{20}-\rho_{40}}{\rho_{40}\,\Delta T}=\dfrac{998-992}{992\times20}=\dfrac{6}{19840}\approx3.0\times10^{-4}\ {}^\circ C^{-1}$. Using $\rho_{20}$ instead of $\rho_{40}$ in the denominator changes the result only in the third significant figure. Option (B) merely echoes the density difference of 6 as a distractor. Water is unusual in that it contracts when heated from 0°C to 4°C and has its maximum density (1000 kg m$^{-3}$) at 4°C.

Answer: (B) New Zealand

Pitt Island (Rangiauria) is the second-largest island of the Chatham Islands group, a remote territory of New Zealand about 800 km east of the mainland. In October 2022 around 240 pilot whales stranded and died on Pitt Island, only days after about 215 had died on the main Chatham Island — nearly 480 in all. A few weeks earlier, some 230 pilot whales had stranded at Macquarie Harbour in Tasmania, Australia, which is a common point of confusion. Pilot whales are actually large oceanic dolphins and are especially prone to mass strandings. New Zealand's capital is Wellington.