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RRB JE CBT-1 2024-25 16 December 2024 Shift 1 GK Questions – with answers & solutions

All 43 GK / GS questions asked in RRB JE CBT-1 2024-25 on 16 December 2024 Shift 1, with correct answers and short solutions, subject-wise: Economics, Biology, Current Affairs, Chemistry, Physics, Geography.

📚 43 questions🗓️ 16 December 2024⏰ Shift 1
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Subjects: Economics (2) · Biology (10) · Current Affairs (5) · Chemistry (9) · Physics (10) · Geography (1) · Polity (3) · Modern History (1) · Medieval History (1) · Static GK (1)

Economics (2)

External Sector and International Economic Organisations · Foreign trade policy and EXIM

Q1. Every year, Foreign Trade Policy has been declared by which ministry of the Government of India?

  1. (a) Ministry of Home Affairs
  2. (b) Ministry of Information
  3. (c) Ministry of Commerce and Industry
  4. (d) Ministry of External Affairs
Answer & solution

Answer: (c) Ministry of Commerce and Industry

Answer: Option 3 — Ministry of Commerce and Industry
India's Foreign Trade Policy (FTP) is framed and announced by the Ministry of Commerce and Industry through its Directorate General of Foreign Trade (DGFT).
Revision note — Foreign Trade Policy of India
• FTP is notified under the Foreign Trade (Development and Regulation) Act, 1992.
• DGFT, headquartered in New Delhi, frames and implements the FTP; it was created in 1991 from the office of the Chief Controller of Imports and Exports.
• FTP 2023 came into force on 1 April 2023; unlike the earlier five-year policies (e.g. FTP 2015–20) it has no end date and is updated as needed.
• FTP 2023 targets exports of USD 2 trillion by 2030 and promotes rupee trade settlement.
• Export schemes under the FTP: RoDTEP (replaced MEIS from 1 January 2021), EPCG, Advance Authorisation.
• Anti-dumping investigations are run by the Directorate General of Trade Remedies (DGTR), also under the Commerce Ministry.
Do not mix these up
• Ministry of Commerce vs Ministry of External Affairs — trade policy is Commerce; diplomacy and foreign relations are External Affairs.
Also asked from this topic: the body that formulates India's Foreign Trade Policy (DGFT); the year DGFT was created (1991); the ministry that handles anti-dumping investigations (Ministry of Commerce and Industry).
Money and Banking · Monetary policy tools (repo, reverse repo, CRR, SLR, MSF, bank rate)

Q2. Which of the following statements accurately describes the role of moral suasion in controlling money?

  1. (a) It is a combination of persuasion and pressure used by the RBI to influence banks' lending behaviour.
  2. (b) It is a direct tool used by the RBI to control the money supply by setting interest rates.
  3. (c) It involves the sale and purchase of government securities to influence the money supply.
  4. (d) It refers to the variation in the statutory liquidity ratio to regulate the allocation of bank credit.
Answer & solution

Answer: (a) It is a combination of persuasion and pressure used by the RBI to influence banks' lending behaviour.

Answer: Option 1 — It is a combination of persuasion and pressure used by the RBI to influence banks' lending behaviour.
In moral suasion the RBI uses advice, requests, meetings and letters to get banks to lend more or less, or to certain sectors.
It has no legal force — it works through the RBI's authority as the regulator.
Revision note — RBI's tools of credit control
• Quantitative (general) tools control the volume of credit: Repo, Reverse Repo, Bank Rate, CRR, SLR, MSF, OMO.
• Qualitative (selective) tools control the direction of credit: moral suasion, margin requirements, credit rationing, selective credit control, direct action.
• Repo rate — rate at which the RBI lends to banks against securities; set by the Monetary Policy Committee (MPC).
• OMO — the RBI buys or sells government securities: buying adds money; selling takes it out.
• SLR — share of deposits banks keep in liquid assets (cash, gold, G-secs); CRR — share kept as cash with the RBI.
• The RBI was set up on 1 April 1935 under the RBI Act, 1934, and nationalised in 1949.
Do not mix these up
• Moral suasion vs OMO — moral suasion is persuasion; OMO is buying and selling G-secs.
• Moral suasion vs SLR / repo — changing SLR or repo is a quantitative, binding measure; moral suasion is qualitative and voluntary.
Also asked from this topic: the RBI tool that is qualitative and not quantitative (moral suasion); the institution that conducts Open Market Operations (RBI).

Biology (10)

Ecology and Environment · Waste management and biodegradable substances

Q3. Which of the following materials is likely to be non-biodegradable?

  1. (a) Paper
  2. (b) Plastic
  3. (c) Vegetable peels
  4. (d) Wood
Answer & solution

Answer: (b) Plastic

Answer: Option 2 — Plastic
Plastic cannot be broken down by microorganisms (bacteria, fungi), so it stays in the environment for hundreds of years.
Paper, wood and vegetable peels are all plant material that decomposers break down.
Revision note — Biodegradable and non-biodegradable substances
• Biodegradable: broken down by biological processes (decomposers) — paper, wood, cotton, food waste, dry leaves, dead animals.
• Non-biodegradable: not broken down by microbes — plastics, polythene, glass, aluminium cans, DDT, styrofoam.
• Non-biodegradable chemicals like DDT pass up the food chain and concentrate at each level — biological magnification.
• Microbes lack the enzymes needed to break the long carbon chains of plastics.
• Waste management rests on the 3Rs — Reduce, Reuse, Recycle.
Also asked from this topic: an example of biodegradable waste (dead animals); the advantage of paper cups over plastic cups (they are biodegradable).
Heredity and Evolution · Sex determination

Q4. If a child inherits an Y chromosome from the father, what will be the sex of the child?

  1. (a) Hermaphrodite
  2. (b) Female
  3. (c) Cannot be determined
  4. (d) Male
Answer & solution

Answer: (d) Male

Answer: Option 4 — Male
The mother always gives an X. If the father's sperm carries Y, the zygote is XY — a male child.
Revision note — Sex determination in humans
• Humans have 46 chromosomes = 23 pairs: 22 pairs of autosomes + 1 pair of sex chromosomes.
• Females are XX; males are XY (the Y is shorter).
• Every egg carries X; half the sperms carry X and half carry Y.
• X sperm + egg → XX (girl); Y sperm + egg → XY (boy).
• So the sex of the child is decided by the father's sperm; the chance of a boy or a girl is 50 : 50.
• In some reptiles (turtles, some lizards) the temperature of incubation decides the sex.
Also asked from this topic: the number of pairs of autosomes in humans (22).
Ecology and Environment · Waste management and biodegradable substances

Q5. Which of the following is an effective method to reduce plastic waste?

  1. (a) Recycling and reusing plastic materials
  2. (b) Using disposable plastic bags
  3. (c) Dumping plastic waste in landfills
  4. (d) Burning plastic waste
Answer & solution

Answer: (a) Recycling and reusing plastic materials

Answer: Option 1 — Recycling and reusing plastic materials
Reusing keeps a plastic item in use longer and recycling turns plastic waste into new products — both cut the plastic that ends up as waste.
Burning releases toxic gases; landfills only store plastic that never decomposes.
Revision note — Managing plastic and other waste
• The 3Rs: Reduce (use less — cloth or jute bags), Reuse (use again), Recycle (reprocess into new items).
• Plastic is non-biodegradable; it can last hundreds of years in soil and water.
• Burning plastic releases harmful gases such as dioxins and carbon monoxide.
• Plastic in drains and water bodies clogs drains and harms aquatic animals.
• India's Plastic Waste Management Rules banned identified single-use plastic items from 1 July 2022 and place Extended Producer Responsibility (EPR) on producers.
Do not mix these up
• Reduce vs reuse — carrying a jute bag instead of taking a plastic bag is reducing; using an old bucket to store things is reusing.
Also asked from this topic: an example of "reducing" in waste management (switching from plastic bags to jute bags); a good waste-management practice (use reusable and recyclable products).
Ecology and Environment · Ecosystem and its components

Q6. Which of the following is a natural ecosystem?

  1. (a) Aquarium
  2. (b) Forest
  3. (c) Crop field
  4. (d) Garden
Answer & solution

Answer: (b) Forest

Answer: Option 2 — Forest
A forest develops and sustains itself without human help, so it is a natural ecosystem.
Aquariums, crop fields and gardens are set up and maintained by humans — artificial (man-made) ecosystems.
Revision note — Ecosystem
• Ecosystem = all living organisms of an area + the non-living surroundings, interacting as one unit.
• Biotic components: producers (green plants), consumers (herbivores, carnivores, omnivores, parasites), decomposers (bacteria, fungi).
• Abiotic components: temperature, rainfall, wind, soil, minerals, water, light.
• Natural ecosystems: forests, ponds, lakes, rivers, grasslands, deserts, oceans.
• Artificial ecosystems: gardens, crop-fields, aquariums, parks, zoos.
• Decomposers return nutrients to the soil; they are missing or controlled in an aquarium, so it must be cleaned regularly.
Do not mix these up
• Garden vs forest — both have plants and animals, but the garden needs human care; the forest does not.
Also asked from this topic: an example of an artificial ecosystem (crop-field); the role of decomposers (recycling nutrients back into the soil); an abiotic component of an ecosystem (soil).
Reproduction · Pollination and fertilisation in plants

Q7. Self pollination is possible only in:

  1. (a) bisexual flowers with both stamens and pistil maturing at the different time
  2. (b) unisexual flowers with pistil maturing first
  3. (c) bisexual flowers with both stamens and pistil maturing at the same time
  4. (d) unisexual flowers with stamen maturing first
Answer & solution

Answer: (c) bisexual flowers with both stamens and pistil maturing at the same time

Answer: Option 3 — bisexual flowers with both stamens and pistil maturing at the same time
Self-pollination means pollen reaches the stigma of the same flower.
So the flower must carry both stamens and pistil (bisexual), and both must be ripe at the same time (homogamy).
Revision note — Pollination
• Pollination — transfer of pollen from the anther to the stigma.
• Self-pollination — within the same flower or another flower of the same plant; e.g. pea, wheat, rice.
• Cross-pollination — pollen reaches a flower on a different plant of the same species; agents: wind, water, insects, birds.
• Bisexual flowers have both stamens and pistil (hibiscus, mustard); unisexual flowers have only one (papaya, watermelon).
• Unisexual flowers can never self-pollinate within the flower — they need cross-pollination.
• Dichogamy (stamens and pistil maturing at different times) prevents self-pollination and favours cross-pollination.
• After pollination, fertilisation — fusion of male and female gametes — forms the zygote.
Do not mix these up
• Pollination vs fertilisation — pollination is transfer of pollen; fertilisation is fusion of gametes.
Also asked from this topic: the difference between pollination and fertilisation (fertilisation is the fusion of gametes); a feature of wind-pollinated flowers (light, small pollen produced in very large numbers).
Reproduction · Seed, fruit and germination

Q8. Which of the following is NOT an agent of dispersal of seeds?

  1. (a) Sunlight
  2. (b) Water
  3. (c) Wind
  4. (d) Animal
Answer & solution

Answer: (a) Sunlight

Answer: Option 1 — Sunlight
Seeds are carried away by wind, water and animals (and some by the bursting of fruits).
Sunlight is needed for the seedling to make food, but it cannot move a seed.
Revision note — Dispersal of seeds
• Why disperse: it avoids competition with the parent plant for sunlight, water and minerals and lets the plant reach new habitats.
• Wind: light or winged seeds — drumstick, maple; hairy seeds — madar (aak), sunflower, cotton.
• Water: seeds with spongy or fibrous coats that float — coconut, lotus.
• Animals: spiny or hooked seeds cling to fur — Xanthium, Urena; fleshy fruits are eaten and seeds passed out.
• Explosion: fruits burst open and throw seeds — castor, balsam.
• After fertilisation the ovary becomes the fruit and the ovules become the seeds.
Also asked from this topic: why angiosperms are more widespread than gymnosperms (fruits enclose and help disperse seeds).
Heredity and Evolution · Sex determination

Q9. What determines the sex of a child in humans?

  1. (a) Genetic constitution
  2. (b) The fate of the embryo
  3. (c) The temperature at which fertilised eggs are placed
  4. (d) Environmental cues
Answer & solution

Answer: (a) Genetic constitution

Answer: Option 1 — Genetic constitution
In humans the sex of a child is genetically determined — by the sex chromosomes it inherits.
The mother always gives an X; the father's sperm gives either X (girl) or Y (boy).
Revision note — Sex determination
• Humans have 46 chromosomes = 23 pairs: 22 pairs of autosomes + 1 pair of sex chromosomes.
• Females are XX; males are XY — the Y chromosome is shorter.
• Every egg carries X; half the sperms carry X and half carry Y.
• X sperm + egg → XX (girl); Y sperm + egg → XY (boy) — the chance of each is 50 : 50.
• So the father's sperm decides the sex of the child.
• In some reptiles the temperature at which fertilised eggs are kept decides the sex; the snail changes sex — environmental control.
Do not mix these up
• Humans vs reptiles — humans: genetic (XX/XY); turtles and some lizards: incubation temperature.
Also asked from this topic: the number of pairs of autosomes in humans (22).
Reproduction · Asexual reproduction (fission, budding, fragmentation, spores)

Q10. What are regenerative cells used by Hydra for?

  1. (a) Hydra uses regenerative cells for reproduction by budding.
  2. (b) Hydra uses regenerative cells for reproduction by spore formation.
  3. (c) Hydra uses regenerative cells for reproduction by fragmentation.
  4. (d) Hydra uses regenerative cells for reproduction by sexual reproduction.
Answer & solution

Answer: (a) Hydra uses regenerative cells for reproduction by budding.

Answer: Option 1 — Hydra uses regenerative cells for reproduction by budding.
In Hydra, regenerative cells divide repeatedly at one spot to form an outgrowth — a bud.
The bud grows into a tiny Hydra and detaches from the parent when mature.
Revision note — Asexual reproduction in single-parent organisms
• Budding — Hydra, yeast; a bud forms on the parent and becomes a new individual.
• Regeneration — Hydra and Planaria can grow a whole body from a cut piece, using specialised cells.
• Binary fission — Amoeba, Paramecium; multiple fission — Plasmodium (malaria parasite).
• Fragmentation — Spirogyra; the filament breaks and each piece grows.
• Spore formation — Rhizopus (bread mould); spores sit in sporangia.
• All these give offspring genetically similar to the one parent.
Do not mix these up
• Budding vs regeneration — both occur in Hydra; budding is its normal mode of reproduction; regeneration is regrowth from a cut piece.
Also asked from this topic: what reproduction in Amoeba, yeast and Hydra with one parent shows (it occurs without fusion of gametes).
Diseases, Immunity and Health · Viral diseases

Q11. Which of the following is a viral infection that can be transmitted through sexual contact?

  1. (a) Syphilis
  2. (b) HIV-AIDS
  3. (c) Gonorrhoea
  4. (d) Tuberculosis
Answer & solution

Answer: (b) HIV-AIDS

Answer: Option 2 — HIV-AIDS
AIDS is caused by the Human Immunodeficiency Virus (HIV) — a virus — and spreads through sexual contact.
Syphilis and gonorrhoea are bacterial; tuberculosis is bacterial and spreads through the air.
Revision note — Sexually transmitted diseases (NCERT Class 10)
• Viral STDs: HIV-AIDS, genital warts (HPV), genital herpes, hepatitis B.
• Bacterial STDs: syphilis (Treponema pallidum), gonorrhoea (Neisseria gonorrhoeae).
• HIV attacks helper T-cells (CD4), weakening the immune system; it is a retrovirus.
• HIV also spreads through infected blood, shared needles, and from mother to child.
• World AIDS Day — 1 December; test for HIV — ELISA.
• Condoms give protection against STDs; surgical methods of contraception do not.
Do not mix these up
• HIV vs AIDS — HIV is the virus; AIDS is the disease stage when the immune system has broken down.
Also asked from this topic: the first successful drug for syphilis (Salvarsan, by Paul Ehrlich); a limitation of surgical contraception regarding STDs (it does not prevent infections).
Reproduction · Asexual reproduction (fission, budding, fragmentation, spores)

Q12. Which of the following is a method of reproduction in plants, where only a single parent is involved?

  1. (a) Sexual reproduction
  2. (b) Fertilisation
  3. (c) Pollination
  4. (d) Asexual reproduction
Answer & solution

Answer: (d) Asexual reproduction

Answer: Option 4 — Asexual reproduction
Asexual reproduction needs only one parent and no fusion of gametes, so the offspring are copies of the parent.
Sexual reproduction, pollination and fertilisation all involve two parents or gametes.
Revision note — Asexual reproduction in plants
• Vegetative propagation — new plants from root, stem or leaf: potato (tuber), ginger (rhizome), Bryophyllum (leaf buds), rose / sugarcane (stem cuttings).
• Artificial methods: cutting, layering, grafting, and tissue culture (micropropagation).
• Spore formation — Rhizopus (bread mould), ferns, mosses.
• Fragmentation — Spirogyra.
• Offspring are genetically identical (clones) — useful traits are kept; plants like banana, orange, rose, jasmine that lose seed-making power are grown this way.
• Drawback: no variation, so less ability to adapt.
Do not mix these up
• Pollination vs fertilisation — pollination is transfer of pollen to the stigma; fertilisation is fusion of male and female gametes — both are steps of sexual reproduction.
Also asked from this topic: why farmers use cutting, grafting and tissue culture (genetically identical plants); what one-parent reproduction in Amoeba, yeast and Hydra shows (it occurs without fusion of gametes).

Current Affairs (5)

National Affairs and Government Initiatives · Health policy and programmes - current

Q13. As of 30 September 2024, how many Jan Aushadhi Kendras have been established by the Government of India across the country?

  1. (a) 13,822
  2. (b) 14,822
  3. (c) 12,822
  4. (d) 11,822
Answer & solution

Answer: (a) 13,822

Answer: Option 1 — 13,822
By 30 September 2024, 13,822 Jan Aushadhi Kendras were functioning across India under the Pradhan Mantri Bhartiya Janaushadhi Pariyojana (PMBJP).
Revision note — Pradhan Mantri Bhartiya Janaushadhi Pariyojana
• Started in 2008 as Jan Aushadhi; relaunched as PMBJP in 2015–16.
• Run by the Department of Pharmaceuticals, Ministry of Chemicals and Fertilizers.
• Implementing agency: Pharmaceuticals and Medical Devices Bureau of India (PMBI).
• Sells quality generic medicines at 50%–90% below branded prices.
• Jan Aushadhi Diwas is observed on 7 March.
• Target: 25,000 Kendras by March 2027.
• As of 2026: the network crossed 15,000 Kendras in March 2025.
Also asked from this topic: the day celebrated to promote generic medicines (Jan Aushadhi Diwas, 7 March).
International Affairs and Summits · Summits and conferences

Q14. Which of the following countries hosted the first business summit of the Bay of Bengal Initiative for Multi-Sectoral Technical and Economic Cooperation (BIMSTEC) in 2024?

  1. (a) Dhaka, Bangladesh
  2. (b) Thimphu, Bhutan
  3. (c) Kathmandu, Nepal
  4. (d) New Delhi, India
Answer & solution

Answer: (d) New Delhi, India

Answer: Option 4 — New Delhi, India
The first BIMSTEC Business Summit was held in New Delhi from 6 to 8 August 2024.
It was organised by the Ministry of External Affairs with the Confederation of Indian Industry (CII) to push trade and investment among member countries.
Revision note — BIMSTEC
• Full form: Bay of Bengal Initiative for Multi-Sectoral Technical and Economic Cooperation.
• Formed on 6 June 1997 by the Bangkok Declaration as BIST-EC (Bangladesh, India, Sri Lanka, Thailand).
• 7 members: Bangladesh, Bhutan, India, Myanmar, Nepal, Sri Lanka, Thailand — five from South Asia, two from South-East Asia.
• Permanent Secretariat at Dhaka, Bangladesh (opened 2014).
• 5th Summit (virtual, Colombo, March 2022) adopted the BIMSTEC Charter.
• India leads the Security pillar (counter-terrorism, disaster management, energy security).
• As of 2026: the 6th BIMSTEC Summit was held in Bangkok, Thailand on 4 April 2025.
Do not mix these up
• BIMSTEC vs SAARC — BIMSTEC Secretariat is in Dhaka; SAARC Secretariat is in Kathmandu.
Also asked from this topic: the declaration that created BIMSTEC (Bangkok Declaration, 1997); the host of the BIMSTEC Summit in April 2025 (Thailand).
Science, Technology and Space - Current · Space missions - current

Q15. Who among the following is India's first civilian space tourist?

  1. (a) Prasanth Balakrishnan Nair
  2. (b) Shubhanshu Shukla
  3. (c) Gopichand Thotakura
  4. (d) Ajit Krishnan
Answer & solution

Answer: (c) Gopichand Thotakura

Answer: Option 3 — Gopichand Thotakura
Gopichand (Gopi) Thotakura, a pilot and entrepreneur from Vijayawada, Andhra Pradesh, became India's first civilian space tourist.
He flew on Blue Origin's New Shepard NS-25 suborbital flight on 19 May 2024.
Revision note — Indians in space
• Rakesh Sharma — first Indian in space, Soyuz T-11, April 1984 ("Saare Jahan Se Achha").
• Kalpana Chawla — first Indian-born woman in space (STS-87, 1997); died in the Columbia disaster (2003).
• Gopichand Thotakura — first Indian space tourist (NS-25, May 2024), crossing the Kármán line (100 km).
• Gaganyaan astronaut-designates (announced February 2024): Prasanth Balakrishnan Nair, Ajit Krishnan, Angad Pratap, Shubhanshu Shukla.
• New Shepard is a reusable suborbital rocket of Blue Origin, founded by Jeff Bezos.
• As of 2026: Shubhanshu Shukla flew to the ISS on Axiom Mission 4 in June–July 2025, the first Indian aboard the ISS.
Do not mix these up
• Space tourist vs astronaut — Thotakura paid as a private passenger; Nair, Krishnan and Shukla are IAF test pilots chosen for Gaganyaan.
Also asked from this topic: the Indian company that launched Agnibaan SOrTeD with a 3D-printed engine (Agnikul); India's first privately developed rocket (Vikram-S, Skyroot Aerospace).
Sports - Current · Olympics, Asian Games and Commonwealth Games - current

Q16. Who among the following secured a gold medal for India at the Paris Paralympics 2024?

  1. (a) Avani Lekhara
  2. (b) Mona Agarwal
  3. (c) Preethi Pal
  4. (d) Nishad Kumar
Answer & solution

Answer: (a) Avani Lekhara

Answer: Option 1 — Avani Lekhara
Avani Lekhara won gold in the women's 10 m air rifle standing SH1 at the Paris 2024 Paralympics, retaining her Tokyo 2020 title.
Revision note — India at the Paris 2024 Paralympics
• Held 28 August – 8 September 2024; India won 29 medals — 7 gold, 9 silver, 13 bronze (its best ever), finishing 18th.
• Golds: Avani Lekhara (shooting), Nitesh Kumar (badminton SL3), Sumit Antil (javelin F64), Harvinder Singh (archery).
• More golds: Dharambir (club throw F51), Praveen Kumar (high jump T64), Navdeep Singh (javelin F41).
• Avani Lekhara became the first Indian woman to win two Paralympic gold medals.
• Mona Agarwal won bronze in the same 10 m air rifle SH1 final.
• Preethi Pal won bronze in 100 m and 200 m T35 — India's first Paralympic track medals.
• Nishad Kumar won silver in high jump T47 (his second Paralympic silver).
• Harvinder Singh won India's first-ever Paralympic archery gold.
Also asked from this topic: India's first Paralympic archery gold at Paris 2024 (Harvinder Singh); gold in men's javelin F41 (Navdeep Singh); the high-jump T64 gold winner with an Asian record (Praveen Kumar).
Reports, Indices and Rankings · National indices and rankings

Q17. Which of the following released the fourth edition of SDG India Index 2023-24?

  1. (a) National Institute for Transforming India
  2. (b) National Crime Record Bureau
  3. (c) National Commission of Backward Classes
  4. (d) National Commission for Women
Answer & solution

Answer: (a) National Institute for Transforming India

Answer: Option 1 — National Institute for Transforming India
The SDG India Index 2023-24 (fourth edition) was released by NITI Aayog (National Institution for Transforming India) on 12 July 2024.
Revision note — SDG India Index
• Launched in 2018 — the world's first government-led sub-national measure of SDG progress.
• Editions: 2018, 2019-20, 2020-21, 2023-24 (fourth).
• India's composite score rose to 71 in 2023-24 from 66 in 2020-21.
• Top states: Uttarakhand and Kerala (79 each); lowest: Bihar (57).
• All States and UTs are placed as Aspirant (0–49), Performer (50–64), Front Runner (65–99), Achiever (100).
• Covers 16 of the 17 SDGs; the UN's 17 SDGs run to 2030.
• NITI Aayog replaced the Planning Commission on 1 January 2015; the Prime Minister is its chairperson.
Also asked from this topic: the world's first government-led sub-national measure of SDG progress (SDG India Index); the range of state composite scores in the SDG India Index 2023-24 (57 to 79).

Chemistry (9)

Metals and Non-metals · Corrosion and its prevention (galvanisation, etc.)

Q18. On oxidation, silver changes its colour to _______ and copper changes its colour to _______.

  1. (a) grey; green
  2. (b) black; blue
  3. (c) black; green
  4. (d) grey; blue
Answer & solution

Answer: (c) black; green

Answer: Option 3 — black; green
Silver reacts with sulphur compounds in air to form a black coat of silver sulphide (Ag_(2)S).
Copper reacts with moist CO_(2) in air to form a green coat of basic copper carbonate.
Revision note — Corrosion of metals
• Corrosion — a metal is slowly eaten away by air, moisture or chemicals around it.
• Iron → reddish-brown rust, hydrated iron(III) oxide Fe_(2)O_(3)·xH_(2)O; needs both air and water.
• Silver → black (Ag_(2)S, from H_(2)S in air).
• Copper → green (CuCO_(3)·Cu(OH)_(2), basic copper carbonate).
• Prevention: painting, oiling, greasing, galvanising (zinc coat), chrome plating, anodising, alloying.
• Gold and platinum do not corrode — they are the least reactive.
Do not mix these up
• Copper heated in air vs copper left in moist air — heating gives black copper(II) oxide; slow corrosion gives a green coat.
Also asked from this topic: why silver articles turn black (a silver sulphide coating forms); the name of the gradual eating away of metals (corrosion).
Acids, Bases and Salts · Common salts - preparation and uses (baking soda, washing soda, bleaching powder, plaster of Paris)

Q19. Why is bleaching powder used for disinfecting drinking water?

  1. (a) It reduces the hardness of water.
  2. (b) It neutralises the water.
  3. (c) It releases chlorine, which kills germs.
  4. (d) It provides an acidic medium.
Answer & solution

Answer: (c) It releases chlorine, which kills germs.

Answer: Option 3 — It releases chlorine, which kills germs.
Bleaching powder, calcium oxychloride (CaOCl_(2)), gives off chlorine, a strong oxidising agent that kills bacteria and other germs in water.
Revision note — Bleaching powder
• Made by passing chlorine over dry slaked lime: Ca(OH)_(2) + Cl_(2) → CaOCl_(2) + H_(2)O.
• The chlorine comes from the chlor-alkali process (electrolysis of brine), which also gives NaOH and H_(2).
• Uses: bleaching cotton and linen in textiles, wood pulp in paper mills, washed clothes in laundry.
• Also an oxidising agent in chemical industries and used to make chloroform.
• Disinfecting drinking water — chlorine is the active agent.
Do not mix these up
• Bleaching powder vs washing soda — bleaching powder disinfects; washing soda (Na_(2)CO_(3)·10H_(2)O) removes permanent hardness.
Also asked from this topic: the gas that gives bleaching powder its bleaching and disinfecting action (chlorine); a use of bleaching powder (disinfecting drinking water; oxidising agent in chemical industries).
Acids, Bases and Salts · pH scale and its importance

Q20. The dark blue colour in the pH scale refers to __________.

  1. (a) strong acidic solution
  2. (b) strong basic solution
  3. (c) weak basic solution
  4. (d) neutral solution
Answer & solution

Answer: (c) weak basic solution

Answer: Option 3 — weak basic solution
On the colour chart of the universal indicator, blue to dark blue covers roughly pH 8 to 11 — a weak base.
The strongest bases (pH 12–14) show violet/purple.
Revision note — pH scale and universal indicator
• pH = measure of hydrogen ion concentration; scale runs 0 to 14 ("p" from German potenz, power).
• pH < 7 acidic, pH = 7 neutral, pH > 7 basic; more H⁺ ions ⇒ lower pH.
• Universal indicator colours: red (strong acid) → orange/yellow (weak acid) → green (neutral) → blue (weak base) → violet (strong base).
• Pure water 7; gastric juice about 1.2; lemon juice about 2.2; blood about 7.4; milk of magnesia about 10; NaOH solution about 14.
• Tooth decay starts when mouth pH falls below 5.5.
• Acid rain has pH below 5.6; plants grow best in soil of pH near neutral.
Do not mix these up
• Universal indicator vs litmus — litmus only tells acid (red) or base (blue); universal indicator shows how strong through a range of colours.
Also asked from this topic: the substance that is neutral on the pH scale (pure water); what a higher H⁺ concentration means for pH (lower pH value).
Acids, Bases and Salts · Common salts - preparation and uses (baking soda, washing soda, bleaching powder, plaster of Paris)

Q21. Washing soda (Na_(2)CO_(3)·10H_(2)O) is obtained from which compound in the Solvay process?

  1. (a) Sodium sulphate
  2. (b) Sodium chloride
  3. (c) Sodium hydroxide
  4. (d) Sodium bicarbonate
Answer & solution

Answer: (d) Sodium bicarbonate

Answer: Option 4 — Sodium bicarbonate
In the Solvay process sodium bicarbonate (NaHCO_(3)) is formed first.
Heating it gives sodium carbonate (Na_(2)CO_(3)), which is recrystallised with water to give washing soda.
Revision note — Solvay (ammonia-soda) process and washing soda
• Raw materials: brine (NaCl), ammonia (NH_(3)), carbon dioxide (CO_(2)) and limestone (CaCO_(3)).
• NaCl + NH_(3) + CO_(2) + H_(2)O → NaHCO_(3) + NH_(4)Cl (sodium bicarbonate settles out).
• 2NaHCO_(3) → Na_(2)CO_(3) + H_(2)O + CO_(2) on heating; anhydrous Na_(2)CO_(3) is called soda ash.
• Na_(2)CO_(3) + 10H_(2)O → Na_(2)CO_(3)·10H_(2)O (washing soda) by recrystallisation.
• Ammonia is recovered from NH_(4)Cl with slaked lime and used again.
• Washing soda is used in glass, soap and paper industries, to make borax, and to remove permanent hardness of water.
• Baking soda (NaHCO_(3)) is used in baking powder, antacids and soda-acid fire extinguishers.
Do not mix these up
• Raw material vs precursor — NaCl is the starting material; washing soda is obtained directly from sodium bicarbonate.
• Baking soda vs washing soda — NaHCO_(3) vs Na_(2)CO_(3)·10H_(2)O (10 water molecules).
Also asked from this topic: the gas needed with ammonia and water to make baking soda (carbon dioxide); industries that use washing soda (glass, soap and paper).
Acids, Bases and Salts · pH scale and its importance

Q22. What is the pH range of a strongly acidic solution?

  1. (a) 0-3
  2. (b) 7-8
  3. (c) 12-14
  4. (d) 10-11
Answer & solution

Answer: (a) 0-3

Answer: Option 1 — 0-3
The lower the pH, the more acidic the solution.
Values close to 0 (about 0–3) mean a strongly acidic solution with a very high H^(+) ion concentration.
Revision note — The pH scale
• pH = potenz (power) of hydrogen ion; the scale runs from 0 to 14.
• pH < 7 → acidic; pH = 7 → neutral (pure water); pH > 7 → basic.
• 0–3 strongly acidic; 11–14 strongly basic; values near 7 are weak.
• Higher [H^(+)] means lower pH; each unit of pH is a 10-fold change in H^(+).
• Common values: gastric juice ≈ 1.2, lemon juice ≈ 2.2, pure water 7, blood ≈ 7.4, milk of magnesia ≈ 10, NaOH solution ≈ 14.
• Tooth decay starts below pH 5.5; the stomach's HCl keeps it strongly acidic; acid rain has pH below 5.6.
• A universal indicator shows the pH by a range of colours.
Do not mix these up
• Strong acid vs concentrated acid — strong means it ionises fully (HCl); concentrated means much acid in little water.
Also asked from this topic: a higher H^(+) concentration means (lower pH); the substance that is neutral on the pH scale (pure water).
Acids, Bases and Salts · Common salts - preparation and uses (baking soda, washing soda, bleaching powder, plaster of Paris)

Q23. What is the process by which sodium hydroxide is prepared?

  1. (a) Contact process
  2. (b) Solvay’s process
  3. (c) Haber’s process
  4. (d) Chlor-alkali process
Answer & solution

Answer: (d) Chlor-alkali process

Answer: Option 4 — Chlor-alkali process
Electricity is passed through brine (aqueous NaCl). It breaks down to give sodium hydroxide, chlorine and hydrogen.
The name comes from the products: chlor (chlorine) + alkali (NaOH).
Revision note — Chlor-alkali process
• Equation: 2NaCl(aq) + 2H_(2)O(l) → 2NaOH(aq) + Cl_(2)(g) + H_(2)(g)
• Chlorine at the anode; hydrogen at the cathode; NaOH forms near the cathode.
• Uses of Cl_(2): water treatment, swimming pools, PVC, disinfectants, CFCs, pesticides, and making bleaching powder.
• Uses of NaOH: soaps and detergents, paper making, artificial fibres, de-greasing metals.
• Uses of H_(2): fuels, hydrogenation of oils (margarine), ammonia for fertilisers.
• Cl_(2) and H_(2) together give HCl, used for cleaning steel and in medicines.
Do not mix these up
• Solvay vs chlor-alkali — the Solvay process makes sodium carbonate (washing soda base); the chlor-alkali process makes sodium hydroxide.
• Haber vs Contact — Haber makes ammonia; Contact makes sulphuric acid.
Also asked from this topic: the name of the process in which brine is electrolysed (chlor-alkali process); the gas released at the cathode (hydrogen); a use of chlorine gas (disinfectants).
Carbon and its Compounds · Chemical properties of carbon compounds (combustion, oxidation, addition, substitution)

Q24. Which of the following reactions represents the combustion of methane?

  1. (a) CH₄ + Cl₂ → CH₃Cl + HCl
  2. (b) CH₄ + O₂ → CO₂ + 2H₂O
  3. (c) CH₄ + O₂ → CO + H₂O
  4. (d) CH₄ + H₂O → CO + H₂
Answer & solution

Answer: (b) CH₄ + O₂ → CO₂ + 2H₂O

Answer: Option 2 — CH₄ + O₂ → CO₂ + 2H₂O
Combustion means burning in oxygen. Methane burns in air to give carbon dioxide, water, heat and light.
The balanced equation is CH_(4) + 2O_(2) → CO_(2) + 2H_(2)O (the option shows the right products; its O_(2) is left unbalanced).
Revision note — Combustion of carbon compounds
• Carbon and its compounds burn in oxygen to give CO_(2) + H_(2)O + heat + light.
• Complete combustion (enough air) gives a blue, non-luminous flame with no soot — as in an LPG or gas stove.
• Incomplete combustion (limited air) gives CO and soot — a yellow, sooty flame that blackens vessels.
• Saturated hydrocarbons (methane, ethane) burn with a clean blue flame; unsaturated ones give a yellow sooty flame.
• Methane (CH_(4)) is the main component of CNG and biogas.
• CH_(4) + Cl_(2) → CH_(3)Cl + HCl (in sunlight) is a substitution reaction, not combustion.
Do not mix these up
• Combustion vs substitution — combustion needs O_(2) and gives CO_(2) + H_(2)O; substitution replaces H with Cl in sunlight.
Also asked from this topic: the sign of complete combustion of methane in a gas burner (a blue, non-luminous flame with no residue); the type of reaction when methane reacts with chlorine in sunlight (substitution).
Acids, Bases and Salts · Neutralisation reaction

Q25. Which of the following reactions does NOT represent a neutralisation reaction?

  1. (a) CH₃COOH + NaOH → CH₃COONa + H₂O
  2. (b) Na₂CO₃ + HCl → NaCl + CO₂ + H₂O
  3. (c) HCl + NaOH → NaCl + H₂O
  4. (d) H₂SO₄ + Ca(OH)₂ → CaSO₄ + 2H₂O
Answer & solution

Answer: (b) Na₂CO₃ + HCl → NaCl + CO₂ + H₂O

Answer: Option 2 — Na₂CO₃ + HCl → NaCl + CO₂ + H₂O
A neutralisation reaction is acid + base → salt + water only.
Sodium carbonate is a metal carbonate, and its reaction with HCl also gives carbon dioxide gas — this is the acid + metal carbonate reaction.
Balanced: Na_(2)CO_(3) + 2HCl → 2NaCl + CO_(2) + H_(2)O.
Revision note — Reactions of acids
• Acid + base → salt + water — neutralisation (e.g. HCl + NaOH → NaCl + H_(2)O).
• The core of every neutralisation is H⁺ + OH⁻ → H_(2)O; the reaction is exothermic.
• Acid + metal carbonate / hydrogencarbonate → salt + CO_(2) + water; CO_(2) turns lime water milky.
• Acid + metal → salt + hydrogen gas (H_(2) burns with a pop sound).
• Acid + metal oxide → salt + water — so metal oxides are basic.
• A weak acid (CH_(3)COOH) or a sparingly soluble base (Ca(OH)_(2)) still gives salt + water — still neutralisation.
Do not mix these up
• Neutralisation vs acid–carbonate reaction — look for CO_(2) among the products; neutralisation gives only salt + water.
Also asked from this topic: the gas released when a dilute acid reacts with a metal carbonate (carbon dioxide); the observation when HCl is added to sodium hydrogen carbonate (effervescence).
Acids, Bases and Salts · Neutralisation reaction

Q26. Which of the following is the product of the neutralisation of hydrochloric acid (HCl) with sodium hydroxide (NaOH)?

  1. (a) Sodium chloride and water
  2. (b) Sodium hydroxide and hydrochloric acid
  3. (c) Sodium hydroxide and water
  4. (d) Sodium chloride and hydrogen gas
Answer & solution

Answer: (a) Sodium chloride and water

Answer: Option 1 — Sodium chloride and water
Acid + base → salt + water.
HCl + NaOH → NaCl + H_(2)O — the salt formed is sodium chloride (common salt).
Revision note — Neutralisation
• H⁺ from the acid and OH⁻ from the base combine to form water: H⁺ + OH⁻ → H_(2)O.
• The remaining ions (Na⁺ and Cl⁻) form the salt.
• Neutralisation is exothermic — heat is released.
• It is also a double displacement reaction (ions are exchanged).
• A strong acid + strong base (HCl + NaOH) gives a neutral salt, pH 7.
• Everyday uses: antacids (milk of magnesia) for acidity, baking soda for ant stings, quicklime / slaked lime for acidic soil.
Also asked from this topic: the ions that form water when HCl reacts with NaOH (H⁺ from HCl and OH⁻ from NaOH); the type of reaction HCl + NaOH → NaCl + H_(2)O also is (double displacement).

Physics (10)

Electricity · Resistors in series and parallel

Q27. In a series combination of resistors, how is the voltage distributed across each resistor?

  1. (a) Directly proportional to resistance
  2. (b) Unaffected by resistance values
  3. (c) The same across all resistors
  4. (d) Inversely proportional to resistance
Answer & solution

Answer: (a) Directly proportional to resistance

Answer: Option 1 — Directly proportional to resistance
In series the same current I flows through every resistor.
By Ohm's law, V = I × R, so with I fixed the larger resistor takes the larger share of voltage.
Revision note — Series and parallel combinations
• Series: same current; voltage divides as V_(1) : V_(2) = R_(1) : R_(2); R_(s) = R_(1) + R_(2) + R_(3).
• Parallel: same voltage; current divides inversely as resistance; 1/R_(p) = 1/R_(1) + 1/R_(2) + 1/R_(3).
• R_(s) is greater than the largest resistor; R_(p) is less than the smallest.
• One bulb failing in series breaks the whole circuit; in parallel the others keep working.
• Household wiring is in parallel, so every appliance gets the full 220 V.
Do not mix these up
• Series vs parallel — series shares voltage, parallel shares current.
Also asked from this topic: what each resistor receives in a parallel combination (the same voltage); why resistors are joined in series (to increase total resistance and limit current).
Electricity · Numericals on electricity

Q28. What is the power rating of a device that draws 1.75 A of current when connected to a 180-V source?

  1. (a) 440 W
  2. (b) 225 W
  3. (c) 315 W
  4. (d) 105 W
Answer & solution

Answer: (c) 315 W

Formula — electric power.
Power = voltage × current
P = V × I
Substitute.
V = 180 V, I = 1.75 A
P = 180 × 1.75
P = 180 × 7/4 = 45 × 7 = 315 W
Answer: 315 W
Revision note — Electric power
• P = VI = I²R = V²/R; SI unit watt (W) = 1 J/s.
• 1 kW = 1000 W; 1 horsepower = 746 W.
• Energy = power × time; commercial unit 1 kWh = 1 unit = 3.6 × 10⁶ J.
• Power rating on a device = energy it uses per second at its rated voltage.
Also asked from this topic: the formula for electrical energy (Energy = Power × Time); 1 kilowatt hour in joules (3.6 × 10⁶ J).
Trap: 180 ÷ 1.75 gives the resistance (about 103 Ω), not the power.
Magnetism and Magnetic Effects of Current · Electromagnetic induction and Faraday's laws

Q29. An emf is induced whenever there is a change in the magnetic field linked with electric circuits. This is stated by the:

  1. (a) Gravitation law
  2. (b) Ohm's law
  3. (c) Faraday's law
  4. (d) Newton's law
Answer & solution

Answer: (c) Faraday's law

Answer: Option 3 — Faraday's law
Faraday's law of electromagnetic induction states that an emf is induced in a circuit whenever the magnetic flux linked with it changes.
Revision note — Electromagnetic induction
• Michael Faraday discovered electromagnetic induction in 1831.
• Induced emf = rate of change of magnetic flux: e = −dΦ/dt (for N turns, e = −N dΦ/dt).
• Lenz's law gives the direction — the induced current opposes the change that causes it (conservation of energy).
• The induced current is larger with more turns, a stronger magnet and faster motion.
• Fleming's right-hand rule gives the direction of induced current in a moving conductor.
• Applications: AC generator (dynamo), transformer, induction cooker.
Do not mix these up
• Faraday's law vs Lenz's law — Faraday tells how much emf is induced; Lenz tells which direction the current flows.
Also asked from this topic: the law that gives the direction of induced current (Lenz's law — it opposes the change in flux); how to increase the induced current (use more turns in the coil).
Electricity · Electric power and electrical energy

Q30. The power in a circuit having voltage V and current I during time interval t is:

  1. (a) I/V
  2. (b) V/I
  3. (c) (I × t)/V
  4. (d) I × V
Answer & solution

Answer: (d) I × V

Answer: Option 4 — I × V
Work done in moving charge Q through potential difference V is W = VQ, and Q = I × t.
Power = work ÷ time = VIt ÷ t = V × I — the time interval cancels out.
Revision note — Electric power
• Electric power = rate at which electrical energy is used: P = VI.
• Using Ohm's law (V = IR): P = I²R = V²/R.
• SI unit watt (W); 1 W = 1 V × 1 A = 1 J/s.
• Electrical energy = P × t = VIt; commercial unit 1 kWh = 3.6 × 10⁶ J.
• A 100 W, 220 V bulb draws I = P/V = 0.45 A.
Do not mix these up
• V/I vs V × I — V/I is resistance (ohm); V × I is power (watt).
Also asked from this topic: the formula for electrical energy (Energy = Power × Time); 1 kilowatt hour in joules (3.6 × 10⁶ J).
Electricity · Resistors in series and parallel

Q31. In a parallel circuit, how does the voltage across each resistor compare to the total voltage supplied by the battery?

  1. (a) It is the same for each resistor.
  2. (b) It is divided according to the resistance values.
  3. (c) It is inversely proportional to the resistance.
  4. (d) It is zero.
Answer & solution

Answer: (a) It is the same for each resistor.

Answer: Option 1 — It is the same for each resistor.
In parallel, every resistor is connected across the same two points of the battery.
So each one gets the full battery voltage; it is the current that divides among them.
Revision note — Series and parallel combinations
• Parallel: same voltage across each; current divides inversely as resistance; 1/R_(p) = 1/R_(1) + 1/R_(2) + 1/R_(3).
• Series: same current through each; voltage divides in proportion to resistance; R_(s) = R_(1) + R_(2) + R_(3).
• R_(p) is less than the smallest resistor; R_(s) is greater than the largest.
• In parallel, one appliance failing does not stop the others.
• Household appliances are wired in parallel, so each gets the full 220 V.
Do not mix these up
• Series vs parallel — series shares voltage, parallel shares current.
Also asked from this topic: the property unique to a parallel combination (each resistor receives the same voltage); why domestic appliances are connected in parallel (each gets equal potential difference).
Electricity · Electric power and electrical energy

Q32. What is the relationship between current (I), power (P), and voltage (V)?

  1. (a) I = PV
  2. (b) I = P ÷ V
  3. (c) I = V ÷ P
  4. (d) I = P2V
Answer & solution

Answer: (b) I = P ÷ V

Answer: Option 2 — I = P ÷ V
Electric power = voltage × current (P = VI).
Dividing both sides by V gives I = P ÷ V.
Revision note — Electric power
• Power is the rate at which electrical energy is used: P = VI.
• With Ohm's law (V = IR): P = I²R = V²/R.
• SI unit watt (W); 1 W = 1 V × 1 A; 1 kW = 1,000 W.
• Electrical energy E = P × t; the commercial unit is the kilowatt-hour (kWh).
• 1 kWh = 3.6 × 10⁶ J = 1 unit on the electricity bill.
Also asked from this topic: resistance of a 60 W bulb on 120 V (R = V²/P = 240 Ω); the formula for electrical energy (Energy = Power × Time).
Magnetism and Magnetic Effects of Current · Electric motor

Q33. The commutator in an electric motor is used to:

  1. (a) reverse the direction of current flowing through the coil
  2. (b) change the direction of the magnetic field
  3. (c) maintain the potential difference in the circuit
  4. (d) maintain the magnetic field in the circuit
Answer & solution

Answer: (a) reverse the direction of current flowing through the coil

Answer: Option 1 — reverse the direction of current flowing through the coil
The split-ring commutator reverses the current in the coil every half rotation.
So the force on each side of the coil keeps pushing the same way, and the coil keeps turning in one direction.
Revision note — Electric motor
• An electric motor converts electrical energy → mechanical energy.
• Principle: a current-carrying conductor in a magnetic field feels a force; its direction is given by Fleming's left-hand rule.
• Parts: armature coil, field magnet, split rings (commutator), carbon brushes, axle.
• The brushes touch the split rings and carry current into the coil.
• A commercial motor uses an electromagnet, a soft-iron core and many turns of wire to increase power.
• Uses: fans, mixers, washing machines, water pumps, computers.
Do not mix these up
• Motor vs generator — a motor turns current into motion (left-hand rule); a generator turns motion into current (right-hand rule).
• Split ring vs slip rings — split ring (commutator) in a DC motor / DC generator; slip rings in an AC generator.
Also asked from this topic: the device that turns electrical energy into mechanical energy (electric motor); what an AC generator uses to take current from the coil (slip rings).
Magnetism and Magnetic Effects of Current · Force on a current-carrying conductor and Fleming's left-hand rule

Q34. Which of the following rules is used to determine the direction of the force on a current-carrying conductor in an electric motor?

  1. (a) Right-Hand Thumb Rule
  2. (b) Ampere's Law
  3. (c) Fleming’s Right-Hand Rule
  4. (d) Fleming’s Left-Hand Rule
Answer & solution

Answer: (d) Fleming’s Left-Hand Rule

Answer: Option 4 — Fleming’s Left-Hand Rule
In a motor, a current-carrying conductor in a magnetic field feels a force.
Its direction is given by Fleming's left-hand rule — the motor rule.
Revision note — Fleming's left-hand rule and the electric motor
• Stretch the thumb, forefinger and middle finger of the left hand mutually perpendicular.
• Forefinger → magnetic field; middle finger → current; thumb → force (motion).
• Force is maximum when current is perpendicular to the field and zero when parallel; F = BIL.
• Reversing either the current or the field reverses the force.
• Electric motor converts electrical energy → mechanical energy; the split-ring commutator reverses current every half turn.
• Fleming's right-hand rule gives the direction of induced current — used for the generator.
• Right-hand thumb rule gives the direction of the magnetic field around a straight wire.
Do not mix these up
• Left hand vs right hand — Left for motor (force); Right for generator (induced current).
Also asked from this topic: what the middle finger shows in Fleming's left-hand rule (direction of current); the finger for the field (index finger); the effect of reversing the current (the force reverses).
Magnetism and Magnetic Effects of Current · Domestic electric circuits, fuse and earthing

Q35. What is the primary purpose of an electric fuse in a household circuit?

  1. (a) To increase current flow
  2. (b) To reduce resistance in the circuit
  3. (c) To prevent overloading and short circuits
  4. (d) To regulate voltage supply
Answer & solution

Answer: (c) To prevent overloading and short circuits

Answer: Option 3 — To prevent overloading and short circuits
A fuse is a safety device. When too much current flows (overloading or a short circuit), the fuse wire melts and breaks the circuit, protecting wiring and appliances.
Revision note — Electric fuse and domestic circuits
• Works on the heating effect of current (H = I²Rt).
• Fuse wire has a low melting point — usually an alloy of tin and lead.
• A fuse is connected in series with the live wire.
• Ratings: 5 A for lights and fans; 15 A for heavy appliances like geysers, ACs, heaters.
• Short circuit — live and neutral wires touch directly; resistance falls and current rises sharply.
• Overloading — too many appliances on one socket, or a voltage surge.
• Earth wire (green insulation) protects the user from shocks from metal-body appliances; MCBs are the modern replacement for fuses.
Do not mix these up
• Fuse vs earthing — a fuse protects the circuit and appliances from excess current; earthing protects the user from electric shock.
Also asked from this topic: the main purpose of a household fuse (to break the circuit if excess current flows); the rating for geysers and coolers (15 A); the colour of the earth wire in India (green).
Magnetism and Magnetic Effects of Current · Solenoid and electromagnet

Q36. The magnetic field inside a long, straight solenoid carrying current is ____________.

  1. (a) zero
  2. (b) inversely proportional to the current
  3. (c) uniform and parallel to the axis of the solenoid
  4. (d) stronger near the edges
Answer & solution

Answer: (c) uniform and parallel to the axis of the solenoid

Answer: Option 3 — uniform and parallel to the axis of the solenoid
Inside a long current-carrying solenoid the field lines are parallel straight lines along the axis.
Equally spaced parallel lines mean the field is the same at all points — uniform.
Revision note — Magnetic field of a solenoid
• Solenoid — a coil of many circular turns of insulated copper wire wrapped close together in the shape of a cylinder.
• Its field pattern outside is like a bar magnet — one end acts as N, the other as S.
• Field strength increases with more turns, more current, and a soft iron core.
• A soft iron rod inside a solenoid becomes an electromagnet — a temporary magnet.
• Electromagnets are used in electric bells, cranes, relays, MRI and loudspeakers.
• The direction of the field is found by the right-hand thumb rule (curl fingers along the current; thumb gives N).
Do not mix these up
• Inside vs outside — inside: uniform, parallel lines; outside: lines spread out from N and curve back to S, like a bar magnet.
Also asked from this topic: why a solenoid can magnetise soft iron placed inside it (it produces a strong and uniform magnetic field inside); the shape of field lines of a solenoid (parallel straight lines inside).

Geography (1)

India - Drainage System · Tributaries and confluences

Q37. Match the following rivers with their tributaries.
[TABLE]
Rivers | Tributaries
1. Brahmaputra | a. Betwa
2. Indus | b. Chenab
3. Yamuna | c. Dibang
[/TABLE]

  1. (a) 1-c, 2-a, 3-b
  2. (b) 1-b, 2-c, 3-a
  3. (c) 1-c, 2-b, 3-a
  4. (d) 1-a, 2-b, 3-c
Answer & solution

Answer: (c) 1-c, 2-b, 3-a

Answer: Option 3 — 1-c, 2-b, 3-a
The lists: 1. Brahmaputra, 2. Indus, 3. Yamuna with a. Betwa, b. Chenab, c. Dibang.
Dibang joins the Brahmaputra, Chenab joins the Indus system, and Betwa joins the Yamuna.
Revision note — Himalayan river systems and their tributaries
• Indus: Jhelum, Chenab, Ravi, Beas, Satluj unite as the Panjnad and join the Indus above Mithankot (Pakistan); also Shyok, Zaskar, Kabul.
• Chenab forms at Tandi (Lahaul-Spiti, HP) from Chandra and Bhaga — hence Chandrabhaga; it is the largest Indus tributary.
• Brahmaputra: Dibang and Lohit join the Dihang (Siang) in upper Assam; right-bank tributaries include Subansiri, Manas, Teesta.
• Yamuna: right-bank Chambal, Sindh, Betwa, Ken; Tons is its largest tributary.
• Betwa rises in the Vindhyas (Madhya Pradesh) and joins the Yamuna near Hamirpur (UP).
Do not mix these up
• Betwa joins the Yamuna, not the Ganga directly; the Son is the Ganga's main right-bank tributary.
Also asked from this topic: the river that the Dibang and Lohit join (Brahmaputra); the largest tributary of the Yamuna (Tons); the river into which the Panjnad flows (Indus); where the Chenab is formed (Tandi).

Polity (3)

Constitutional and Non-Constitutional Bodies · Finance Commission

Q38. Which of the following articles deals with the Finance Commission that distributes taxes between the Centre and State?

  1. (a) Article 282
  2. (b) Article 283
  3. (c) Article 280
  4. (d) Article 281
Answer & solution

Answer: (c) Article 280

Answer: Option 3 — Article 280
Article 280 requires the President to constitute a Finance Commission every five years (or earlier).
It recommends how the net proceeds of taxes are divided between the Centre and the States, and among the States.
Revision note — Finance Commission
• A quasi-judicial constitutional body; 1 Chairman + 4 members, appointed by the President.
• Qualifications of members are fixed by Parliament — Finance Commission (Miscellaneous Provisions) Act, 1951.
• 1st Finance Commission (1951) — Chairman K.C. Neogy.
• 15th FC — N.K. Singh; states' share 41% of the divisible pool (2021–26).
• 16th FC (constituted 31 December 2023) — Chairman Arvind Panagariya, for 2026–31.
• Recommendations are advisory, not binding; under Article 281 the President lays them before Parliament.
• Article 275 — statutory grants-in-aid; Article 282 — discretionary grants.
Do not mix these up
• Article 280 vs Article 243-I / 243-Y — 280 is the Union Finance Commission; the State Finance Commission for panchayats and municipalities comes under 243-I and 243-Y.
Also asked from this topic: who appoints the Chairman and members of the Finance Commission (the President); the Article for statutory grants-in-aid to States (Article 275).
Union Executive · Vice-President

Q39. Which of the following articles deal with the provisions regarding the election, qualification, and removal of the Vice-President of India?

  1. (a) Article 78 - 80
  2. (b) Article 224 - 245
  3. (c) Article 68 - 75
  4. (d) Article 63 - 71
Answer & solution

Answer: (d) Article 63 - 71

Answer: Option 4 — Article 63 - 71
Articles 63 to 71 (Part V) cover the Vice-President — office, election, qualifications, term, removal, oath and election disputes.
Revision note — Vice-President of India
• Art. 63 — there shall be a Vice-President; Art. 64 — ex-officio Chairman of the Rajya Sabha.
• Art. 65 — acts as President when that office is vacant.
• Art. 66 — elected by all members of both Houses (elected and nominated).
• Voting by proportional representation — single transferable vote, secret ballot.
• Qualifications: citizen, 35 years of age, qualified for election to the Rajya Sabha.
• Art. 67 — term 5 years; resigns to the President.
• Removed by a Rajya Sabha resolution (effective majority) agreed to by the Lok Sabha, after 14 days' notice.
• Art. 69 — oath before the President; Art. 71 — election disputes decided by the Supreme Court.
• Salary is fixed by Parliament, drawn as Chairman of the Rajya Sabha.
Do not mix these up
• President vs Vice-President electoral college — the President's includes elected MLAs and only elected MPs; the Vice-President's has all MPs and no MLAs.
• Articles 52–62 are the President; Articles 74–75 are the Council of Ministers.
Also asked from this topic: to whom the Vice-President submits his resignation (the President); who decides disputes over his election (Supreme Court); minimum age for the post (35 years).
DPSP and Fundamental Duties · Swaran Singh Committee and 42nd/86th amendments

Q40. Which of the following committees suggested that the 'duty to pay taxes' should also be a Fundamental Duty of the Indian citizen?

  1. (a) Sarkaria Commission
  2. (b) Justice JS Verma Committee
  3. (c) Swaran Singh Committee
  4. (d) Santhanam Committee
Answer & solution

Answer: (c) Swaran Singh Committee

Answer: Option 3 — Swaran Singh Committee
The Swaran Singh Committee (1976) recommended Fundamental Duties, and among its suggestions was the duty to pay taxes.
Parliament did not accept that duty when it added Article 51A.
Revision note — Fundamental Duties
• Set up by the Congress party in 1976, during the Emergency; it recommended 8 duties.
• The 42nd Amendment Act, 1976 added 10 duties in Part IVA, Article 51A — more than the committee proposed.
• Suggestions not adopted: the duty to pay taxes, and penalties by Parliament for not complying with the duties.
• The 86th Amendment Act, 2002 added the 11th duty, 51A(k) — parents to give education opportunities to children aged 6–14.
• Idea borrowed from the USSR constitution; the duties are non-justiciable.
• The Justice J.S. Verma Committee on Fundamental Duties (1998, report 1999) listed laws that already enforce some duties.
Do not mix these up
• Swaran Singh vs J.S. Verma — Swaran Singh proposed the duties (1976); J.S. Verma reviewed their enforcement (1999).
• Sarkaria vs Santhanam — Sarkaria (1983) is Centre–State relations; Santhanam (1962) is prevention of corruption, leading to the CVC.
Also asked from this topic: the committee that recommended Fundamental Duties (Swaran Singh Committee); the amendment that added them (42nd, 1976); the 86th Amendment duty (education, ages 6–14).

Modern History (1)

Rise of Nationalism and Indian National Congress · Foundation of the INC (1885)

Q41. The first session of Indian National Congress took place at which of the following places?

  1. (a) Bombay
  2. (b) Lahore
  3. (c) Allahabad
  4. (d) Calcutta
Answer & solution

Answer: (a) Bombay

Answer: Option 1 — Bombay
The first session of the Indian National Congress met in Bombay on 28–31 December 1885, at the Gokuldas Tejpal Sanskrit College.
Revision note — Foundation of the Indian National Congress
• Founded by A.O. Hume, a retired British civil servant, who became its first General Secretary.
• First President: W.C. Bonnerjee; 72 delegates attended.
• The session was planned for Poona but moved to Bombay because of a cholera outbreak.
• 2nd session: Calcutta, 1886 (Dadabhai Naoroji); 3rd: Madras, 1887 (Badruddin Tyabji, first Muslim president).
• First British president: George Yule (Allahabad, 1888); first woman president: Annie Besant (Calcutta, 1917).
• First Indian woman president: Sarojini Naidu (Kanpur, 1925).
• Viceroy at the time of its founding: Lord Dufferin.
Also asked from this topic: the first President of the INC (W.C. Bonnerjee); the founder of the INC (A.O. Hume); the first British President (George Yule, 1888); the first woman President (Annie Besant, 1917).

Medieval History (1)

Bhakti, Sufi and Sikh Movements · Bhakti in Maharashtra and Bengal (Namdev, Tukaram, Chaitanya)

Q42. Chaitanya Mahaprabhu was related to which of the following religious sects?

  1. (a) Vaishnava
  2. (b) Kapalika
  3. (c) Shaiva
  4. (d) Tantra
Answer & solution

Answer: (a) Vaishnava

Answer: Option 1 — Vaishnava
Chaitanya Mahaprabhu was a Vaishnava Bhakti saint of Bengal, devoted to Krishna (Vishnu).
He founded the Gaudiya Vaishnava tradition.
Revision note — Chaitanya Mahaprabhu and Bengal Vaishnavism
• Born 1486 at Nabadwip (Navadvipa), Bengal; died 1534 at Puri, Odisha.
• Popularised sankirtan — group singing and dancing in praise of Krishna and Radha.
• Taught devotion (bhakti) open to all, rejecting caste barriers and ritualism.
• His disciples, the Six Goswamis of Vrindavan, gave the movement its texts.
• ISKCON (Hare Krishna movement), founded in 1966 by A.C. Bhaktivedanta Swami Prabhupada, follows his tradition.
• Other Vaishnava saints: Alvars (Tamil), Ramanuja, Ramananda, Vallabhacharya, Surdas, Mirabai, Shankaradeva (Assam).
Do not mix these up
• Vaishnava vs Shaiva — Vaishnavas worship Vishnu (Alvars); Shaivas worship Shiva (Nayanars, Kapalikas, Virashaivas).
Also asked from this topic: the name for the Vaishnavite saints of Tamil Bhakti (Alvars); the language of Sant Tukaram's abhangs (Marathi); the scripture on which Jnaneshwari is a commentary (Bhagavad Gita).

Static GK (1)

Festivals, Fairs, Paintings and Crafts · Festivals by state

Q43. Where is the Taj Mahotsav held?

  1. (a) Near the Western gate of Taj Mahal
  2. (b) In Fatehpur Sikri
  3. (c) Near the Eastern gate of Taj Mahal
  4. (d) In Agra Fort
Answer & solution

Answer: (c) Near the Eastern gate of Taj Mahal

Answer: Option 3 — Near the Eastern gate of Taj Mahal
The Taj Mahotsav is held every year at Shilpgram, an open-air craft venue near the Eastern Gate of the Taj Mahal in Agra.
Revision note — Taj Mahotsav
• A 10-day festival held every year from 18 to 27 February.
• Organised by Uttar Pradesh Tourism; first held in 1992.
• Showcases arts, crafts, music, dance and cuisine from across India — marble inlay, zari, chikankari, carpets.
• Themed on the Mughal era and Nawabi style of Uttar Pradesh.
• The Taj Mahal (built by Shah Jahan for Mumtaz Mahal; chief architect Ustad Ahmad Lahori) became a UNESCO World Heritage Site in 1983.
• Other festivals of UP: Kumbh Mela (Prayagraj), Lucknow Mahotsav, Dev Deepawali (Varanasi), Ram Barat (Agra).
Also asked from this topic: the year the Taj Mahal was inscribed as a UNESCO World Heritage Site (1983); the chief architect of the Taj Mahal (Ustad Ahmad Lahori).
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