Explanation: The Harappans did NOT use iron. The Great Bath is at Mohenjodaro; trade contacts with Mesopotamia and grid-planning are confirmed.

Explanation: Megaliths found across South India are associated with Iron Age burial practices, dating from ~1000 BCE to 100 CE.

Explanation: Pratityasamutpada (Dependent Origination) is a core concept in Buddhist philosophy — all phenomena arise in dependence upon conditions.

Explanation: Sangam literature was produced in literary assemblies (Sangams), roughly between 300 BCE and 300 CE. It includes Tolkappiyam and Purananuru.

Explanation: The Ashokan Edicts (3rd century BCE) are the first royal proclamations inscribed on rock and pillars across the subcontinent, written in Prakrit (Brahmi/Kharosthi scripts).

Explanation: Nalanda (5th century CE) was primarily a Buddhist monastic university attracting scholars from across Asia. It was destroyed by Bakhtiyar Khilji around 1200 CE.

Explanation: Ain-i-Akbari was written by Abul Fazl (one of the Navaratnas). It is the third volume of Akbarnama, providing a detailed statistical account of Akbar's empire.

Explanation: Battle of Plassey (June 1757) between Robert Clive and Siraj ud-Daulah established British political dominance in Bengal, laying the foundation for the British Empire in India.

Explanation: The Permanent Settlement fixed land revenue permanently with the zamindars, making them proprietors of land. It was limited to Bengal, Bihar, and Orissa.

Explanation: The INC was founded largely with A.O. Hume's initiative as a platform for educated Indians to interact with the British government through constitutional means.

Explanation: The Quit India Movement was launched on 8 August 1942 after the failure of the Cripps Mission (March 1942), which offered only post-war dominion status.

Explanation: The Hunter Commission (Indian Education Commission, 1882-83) reviewed progress of education since Wood's Despatch (1854) and recommended greater support for vernacular elementary education.

Explanation: The Rowlatt Act (Anarchical and Revolutionary Crimes Act, 1919) allowed arrest and imprisonment without trial or jury for up to two years. It was called the 'Black Act'.

Explanation: The Wavell Plan (Simla Conference, June-July 1945) proposed an Executive Council with equal 'Caste Hindus' and Muslims. It failed because Jinnah insisted on exclusive Muslim League nominations.

Explanation: The GoI Act 1935 ABOLISHED dyarchy in provinces (not introduced it) and introduced provincial autonomy. It proposed dyarchy at the federal/centre level. Option B is incorrect.

Explanation: The Preamble declares India a 'Sovereign Socialist Secular Democratic Republic'. 'Socialist' and 'Secular' were added by the 42nd Amendment (1976). 'Federal' does not appear in the Preamble.

Explanation: Under the 44th Amendment, Articles 20 and 21 (Protection from conviction and Right to Life) CANNOT be suspended even during a National Emergency.

Explanation: Judicial Review is the power of the Supreme Court and High Courts to examine whether laws or executive actions conform to the Constitution. Unconstitutional acts can be declared null and void.

Explanation: Zero Hour refers to the time beginning at noon, immediately after Question Hour. Members can raise urgent matters of public importance without prior notice. It has evolved as a convention since 1962.

Explanation: The 61st Constitutional Amendment Act, 1988 reduced the voting age for Lok Sabha and state assembly elections from 21 to 18 years, effective 28 March 1989.

Explanation: The Finance Commission (constituted every 5 years under Article 280) recommends distribution of net tax proceeds between Union and States and principles governing grants-in-aid to states.

Explanation: India has a single constitution for both the Union and States. In the US, each state has its own constitution. India also has single citizenship, unlike the US's dual citizenship system.

Explanation: The Anti-Defection Law is in the Tenth Schedule (added by 52nd Constitutional Amendment, 1985). It disqualifies members who voluntarily give up party membership or vote against party directions.

Explanation: The Speaker can be removed by a resolution of Lok Sabha passed by an effective majority, but only after giving 14 days' prior notice of the intention to move such a resolution (Article 94).

Explanation: The Planning Commission was NOT in the Constitution; it was set up by Cabinet Resolution in 1950 and replaced by NITI Aayog in 2015. EC (Art.324), Finance Commission (Art.280), UPSC (Art.315) are all constitutional bodies.

Explanation: The Deccan Traps are one of the world's largest volcanic features, formed by massive eruptions ~65-66 million years ago (end-Cretaceous). They cover a large area of the Deccan Plateau with basaltic lava flows.

Explanation: Barchans are crescent-shaped (horseshoe-shaped) dunes formed when wind blows consistently from one direction in arid areas with limited sand. The horns point in the downwind direction.

Explanation: The Coriolis Effect, caused by Earth's rotation, deflects moving objects to the RIGHT in the Northern Hemisphere and to the LEFT in the Southern Hemisphere, influencing wind patterns and cyclone rotation.

Explanation: The Continental Shelf is the gently sloping submerged extension of a continent from the coastline to the continental slope. Under UNCLOS, coastal states have sovereign rights over their continental shelf.

Explanation: Gujarat has the longest coastline of any Indian state (~1,600 km) due to the highly indented nature including the Gulf of Kutch and Gulf of Khambhat. It accounts for about 23% of India's total coastline.

Explanation: The Trans-Himalayan (Tibetan Himalayan) region lies north of the main Himalayan range and includes Ladakh, Spiti, Lahaul, and Zanskar. It has a cold, arid climate similar to the Tibetan Plateau.

Explanation: Eutrophication is caused by excessive nutrients (often from agricultural fertiliser runoff), leading to algal blooms, oxygen depletion, and death of aquatic life.

Explanation: The Eastern Ghats are discontinuous and irregular, cut through by the Mahanadi, Godavari, Krishna, and Kaveri rivers. Their average elevation is also lower than the Western Ghats.

Explanation: The Brahmaputra is an antecedent river — it existed before the Himalayas formed and cut through them as they rose. It originates as the Tsangpo in Tibet, flows east, then makes a dramatic U-turn around Namcha Barwa peak.

Explanation: The Indian Monsoon is primarily caused by seasonal reversal of pressure and wind systems due to differential heating of the Asian landmass and the Indian Ocean, drawing in moisture-laden winds from the ocean.

Explanation: The Phillips Curve shows an empirical inverse relationship between the rate of inflation and the rate of unemployment. High unemployment associates with low inflation and vice versa.

Explanation: India's GDP is measured both at Factor Cost (excluding indirect taxes, including subsidies) and at Market Prices (including indirect taxes, excluding subsidies). Both measures are used in national income accounting.

Explanation: Hawala is an informal value transfer system based on a network of brokers (hawaladars) and trust, operating outside formal banking channels. It is illegal in India when used to circumvent exchange control laws.

Explanation: SEBI regulates stock exchanges, registers FPIs, and protects investors. Setting monetary policy and interest rates is the exclusive function of the RBI's Monetary Policy Committee — NOT SEBI.

Explanation: GFD = Total Expenditure − (Revenue Receipts + Non-Debt Capital Receipts). It represents the total borrowing requirement of the government. The FRBM Act targets keeping it below 3% of GDP.

Explanation: The Base Effect refers to the impact of the reference period on inflation calculation. If the base period had an unusually high price level, current inflation appears lower even if actual prices haven't changed much.

Explanation: Dutch Disease refers to the adverse impact on manufacturing and agriculture when there is a large increase in revenues from natural resources (e.g., oil). The term originated after the Netherlands discovered North Sea gas in 1959.

Explanation: The Yield Curve plots interest rates (yields) of bonds against their maturity periods. An inverted yield curve (short-term yields exceed long-term) is often seen as a recession predictor.

Explanation: Human Capital Theory was developed by Gary Becker (Nobel 1992) and Theodore Schultz (Nobel 1979), who argued that investment in education and training yields returns through higher productivity.

Explanation: The IBC was enacted in 2016. It provides a consolidated framework for resolving insolvency cases for individuals, companies, and LLPs. It established the NCLT as the adjudicating authority.

Explanation: Under PSL guidelines (RBI), banks must lend at least 40% of ANBC to priority sectors including agriculture, micro and small enterprises, education, housing, and renewable energy.

Explanation: Fiat money is money declared by the government to be legal tender. Its value is not backed by any physical commodity like gold but derives from government decree and public trust. Most modern currencies are fiat money.

Explanation: The Narasimham Committee focused on banking and financial sector reforms. Key recommendations included reducing SLR/CRR, independent banking supervision, asset reconstruction companies, and prudential NPA norms.

Explanation: Albedo is the fraction of solar radiation reflected by a surface. Snow/ice have high albedo (~90%), while oceans and forests have low albedo. Loss of ice due to global warming reduces Earth's albedo — a positive feedback loop.

Explanation: BOD is the amount of dissolved oxygen needed by aerobic biological organisms to break down organic material in water at a given temperature over a specific time period. High BOD indicates high organic pollution.

Explanation: The Biological Diversity Act, 2002 established the National Biodiversity Authority (NBA) at the national level, State Biodiversity Boards at state level, and Biodiversity Management Committees at local level.

Explanation: The stratospheric ozone layer (15-35 km altitude) absorbs most of the Sun's UV-B and UV-C radiation. UV-B is particularly harmful, causing skin cancer and cataracts. The Montreal Protocol (1987) successfully addressed ozone depletion.

Explanation: An Ecotone is a transition zone between two different ecosystems where elements of both meet (e.g., forest-grassland boundary, mangroves). Ecotones often have high biodiversity due to the edge effect.

Explanation: SF6 has a GWP of about 23,900 over 100 years. For comparison: CH4 ~25-28, N2O ~265-298, CO2 = 1 (baseline). SF6 is used in electrical equipment but is an extremely potent greenhouse gas.

Explanation: The Minamata Convention on Mercury (2013) protects human health and the environment from anthropogenic emissions of mercury. Named after Minamata, Japan, where severe mercury poisoning occurred in the 1950s-60s.

Explanation: Carrying capacity (K) is the maximum population size of a species that an environment can sustain indefinitely given available resources. When a population exceeds K, it often crashes due to resource depletion.

Explanation: The NAPCC was launched in June 2008 with eight National Missions including: National Solar Mission, Energy Efficiency Mission, Sustainable Habitat, Water Mission, Himalayan Ecosystem, Green India, Sustainable Agriculture, and Strategic Knowledge.

Explanation: The correct IUCN sequence (increasing threat): Least Concern → Near Threatened → Vulnerable → Endangered → Critically Endangered → Extinct in the Wild → Extinct. Species can also be Data Deficient or Not Evaluated.

Explanation: Nuclear Fusion combines light atomic nuclei (like hydrogen isotopes) to form heavier nuclei, releasing enormous energy. Nuclear Fission splits heavy nuclei (uranium, plutonium). The Sun's energy comes from fusion. Nuclear power plants use fission.

Explanation: Moore's Law, articulated by Intel co-founder Gordon Moore in 1965, states that the number of transistors on a microchip (and hence computing power) doubles approximately every two years.

Explanation: CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats — natural sequences in bacterial genomes used in their immune system. The CRISPR-Cas9 editing tool was developed by Doudna and Charpentier (Nobel 2020).

Explanation: IoT refers to the interconnected network of physical objects — devices, vehicles, appliances — embedded with sensors, software, and connectivity to collect and exchange data over the internet.

Explanation: The Higgs Boson is associated with the Higgs field (proposed by Peter Higgs, 1964). The Higgs field gives mass to other particles. Its discovery at CERN's LHC in 2012 confirmed the Standard Model. Higgs shared the 2013 Nobel Prize in Physics.

Explanation: Photosynthesis: 6CO2 + 6H2O + light energy → C6H12O6 (glucose) + 6O2. Chlorophyll captures light energy to convert CO2 and water into glucose and oxygen. This is the primary process by which organic matter is produced.

Explanation: The Hubble Space Telescope (launched 1990) primarily observes in visible light, near-ultraviolet, and near-infrared wavelengths. Being above Earth's atmosphere allows observation without atmospheric distortion.

Explanation: Tejas is India's indigenously designed, developed, and manufactured Light Combat Aircraft produced by HAL. It is a single-engine, delta-wing, multirole fighter that entered service with the Indian Air Force.

Explanation: A blockchain is a distributed, decentralised ledger recording transactions in a chain of blocks. Each block contains a cryptographic hash of the previous block, making it extremely difficult to alter. It underpins cryptocurrencies and has many applications.

Explanation: The Doppler Effect (named after Christian Doppler) describes the change in frequency perceived by an observer when the source and observer are in relative motion. Used in radar, sonar, and astronomy (red shift/blue shift).

Explanation: Vaccines present the immune system with an antigen (weakened pathogen, protein, or mRNA instructions) that stimulates an immune response and creates immunological memory — without causing actual disease.

Explanation: NEP 2020 proposes 5+3+3+4 structure: Foundational (5 years: 3 pre-primary + Grades 1-2), Preparatory (3 years: Grades 3-5), Middle (3 years: Grades 6-8), Secondary (4 years: Grades 9-12). Replaces 10+2.

Explanation: Jal Jeevan Mission (Har Ghar Jal), launched 2019, aims to provide functional household tap connections (FHTC) to every rural household in India by 2024, supplying potable water at 55 litres per person per day.

Explanation: The SVAMITVA Scheme uses drones to conduct aerial surveys of inhabited land in rural areas, enabling accurate property records and the issuance of 'property cards' to rural household owners.

Explanation: POSHAN Abhiyaan (2018), India's flagship nutrition mission, targets reduction of stunting, wasting, under-nutrition, and anaemia through a multi-sectoral convergence approach for children (0-6 years) and women.

Explanation: DAP 2020 introduced IDDM (Indigenously Designed, Developed and Manufactured) as the highest priority procurement category, requiring at least 50% indigenous content, promoting self-reliance under 'Atmanirbhar Bharat'.

Explanation: Covaxin was developed by Bharat Biotech International Limited (BBIL) jointly with ICMR/National Institute of Virology (NIV). It is a whole-virion inactivated vaccine (BBV152), which received WHO Emergency Use Listing in November 2021.