Minerals, energy & industry

Answer: (d) Waste-to-energy technologies

Pyrolysis and plasma gasification are waste-to-energy technologies: they treat waste (such as plastics and municipal solid waste) at high temperature and turn it into fuel oil or syngas that can generate power.

• ✓ (d) In pyrolysis, waste is heated (400-600°C) without oxygen to give pyrolysis oil and gas. In plasma gasification, a plasma arc above 3000°C turns waste into syngas, which can run gas engines to make electricity.
• ✗ (a) Rare earth elements are recovered from ores by mining and chemical processing, not by these thermal waste treatments.
• ✗ (b) Natural gas extraction uses drilling and hydraulic fracturing; neither term belongs there.
• ✗ (c) Hydrogen vehicles run on fuel cells or hydrogen engines; pyrolysis and gasification are not vehicle technologies.

Remember · Pyrolysis (heating waste without oxygen) and plasma gasification (waste to syngas in a plasma arc above 3000°C) are waste-to-energy routes for plastics and solid waste.

Question and answer: UPSC's official GS Paper I (2019, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (d) 1, 2 and 3

All three statements are correct. Methane hydrate is an ice-like solid holding methane, found in Arctic permafrost and in sea-floor sediments; it releases methane when it warms, and methane that reaches the air lasts about a decade before it is oxidised to carbon dioxide.

• ✓ 1. Methane hydrate is stable only at low temperature and high pressure. Warming makes the hydrate release its methane, which is why global warming could trigger releases.
• ✓ 2. Gas hydrates occur in huge quantities in marine sediments just below the sea floor and in association with permafrost in the Arctic.
• ✓ 3. Methane is short-lived in the air: it lasts about a decade on average (IPCC AR6 gives 11.8 years). It is broken down by oxidation, ending as carbon dioxide and water.

Remember · Methane hydrate = methane locked in ice-like crystals under permafrost and seabed. Warming can release it; airborne methane lasts about 12 years and then oxidises to CO2.

Question and answer: UPSC's official GS Paper I (2019, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (a) 1 only

Only statement 1 is correct. Coking coal mines were nationalised in 1971-72 and non-coking coal mines in 1973, while Indira Gandhi was Prime Minister. Coal blocks are given out by competitive auction, not by lottery, and India still imports coal.

• ✓ 1. The Central Government nationalised private coal mines in two phases: coking coal mines in 1971-72 and non-coking coal mines in 1973 (Coal Mines (Nationalisation) Act, 1973). Indira Gandhi was Prime Minister from 1966 to 1977.
• ✗ 2. Blocks are now allotted through competitive bidding, that is auctions, conducted by the Nominated Authority under the Coal Mines (Special Provisions) Act, 2015. There is no lottery.
• ✗ 3. India is not self-sufficient. It still imports coking coal and high-grade thermal coal that its domestic reserves do not supply in sufficient quantity.

Remember · Coal was nationalised in 1971-73 under Indira Gandhi; blocks are now auctioned (not lotteried), and India still imports coking coal.

Question and answer: UPSC's official GS Paper I (2019, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (a) 1 and 3 only

Statements 1 and 3 are correct; statement 2 is wrong. The Mines and Minerals (Development and Regulation) Act, 1957 lists ordinary sand as a minor mineral, and it is the State Government, not the Centre, that makes the rules for granting minor mineral leases (section 15) and for preventing illegal mining (section 23C).

• ✓ 1. Section 3(e) of the MMDR Act defines minor minerals as building stones, gravel, ordinary clay and ordinary sand (other than sand used for prescribed purposes), plus any mineral the Centre notifies as minor.
• ✗ 2. Section 15 says the State Government may make rules for regulating the grant of quarry leases, mining leases and other concessions for minor minerals. The rule-making power lies with the State, not the Centre.
• ✓ 3. Section 23C lets the State Government make rules for preventing illegal mining, transportation and storage of minerals.

Remember · Minor minerals (including ordinary sand) are regulated by States: they frame the leasing rules (s.15) and the anti-illegal-mining rules (s.23C). The Centre only notifies which extra minerals count as minor.

Question and answer: UPSC's official GS Paper I (2019, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (b) 2 and 3 only

Statements 2 and 3 are correct. The PNGRB Act, 2006 aims to promote competitive markets in petroleum and natural gas, and appeals against the Board's orders go to the Appellate Tribunal for Electricity. PNGRB is not the first regulator set up by the Government: the Reserve Bank of India, for one, dates from 1935.

• ✗ 1. The PNGRB Act was passed in 2006, whereas the Reserve Bank of India, a regulator of banking, was established on 1 April 1935. PNGRB is therefore far from the first regulatory body.
• ✓ 2. The Act's stated purpose includes promoting competitive markets, and the Board's functions include protecting consumers by fostering fair trade and competition among entities and regulating pipeline access to ensure fair competition.
• ✓ 3. Under section 30 of the PNGRB Act, the tribunal that hears appeals against Board orders is the same one that the Electricity Act, 2003 (section 110) created, now known as APTEL.

Remember · PNGRB (Act of 2006) regulates downstream petroleum and natural gas, promotes competitive markets, and its appeals go to the Appellate Tribunal for Electricity.

Question and answer: UPSC's official GS Paper I (2019, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error