Explanation:

Statement 1 is correct: The stratospheric ozone layer (about 15–35 km altitude) absorbs virtually all UV‑C and most UV‑B radiation from the Sun, thereby shielding Earth’s surface and living organisms from harmful ultraviolet radiation.

Statement 2 is correct: Ozone depletion is linked to chlorofluorocarbons (CFCs). CFCs, once in the stratosphere, are photolyzed by UV light, releasing chlorine radicals that catalytically destroy ozone (e.g., Cl + O3 → ClO + O2), contributing to phenomena like the Antarctic ozone hole. This understanding underpins the Montreal Protocol restricting CFCs.

Therefore, both statements are correct.

Explanation:

Statement 1 is incorrect: Atal Tunnel (about 9.02 km) is not the world’s longest highway tunnel. The Lærdal Tunnel in Norway (about 24.5 km) is longer. Atal Tunnel’s distinction is being the world’s longest highway tunnel at high altitude (above 10,000 ft), not overall.

Statement 2 is correct: The tunnel passes under Rohtang Pass in Himachal Pradesh and is built in the eastern Pir Panjal range of the Himalayas.

Hence, only statement 2 is correct.
– Option 1 (Only 2): Correct.

Explanation:

A gas is lighter than air if its molar mass (or density at the same conditions) is less than that of air (~29 g/mol; density ~1.225 g/L at STP).
– Hydrogen chloride (HCl): Molar mass ≈ 36.5 g/mol; density ≈ 1.49 g/L. Heavier than air → not lighter.
– Sulfur dioxide (SO2): Molar mass ≈ 64 g/mol; density ≈ 2.93 g/L. Heavier than air → not lighter.
– Helium (He): Molar mass ≈ 4 g/mol; density ≈ 0.1785 g/L. Much lighter than air → lighter.
Thus, only Helium is lighter than air.

Explanation:

Statement 1 is correct: The Public Accounts Committee (PAC) presents/submits its reports to the Lok Sabha (through the Speaker). These reports are then laid on the Table of the Rajya Sabha, but the primary submission is to the Lok Sabha.

Statement 2 is incorrect: The PAC has 22 members—15 from the Lok Sabha and 7 from the Rajya Sabha. It does not have 15 members from the Rajya Sabha.

Therefore, only Statement 1 is correct.

Explanation:

Chronological order:
1) Cripps Mission (March–April 1942)
2) Wavell Plan (announced 14 June 1945)
3) Shimla Conference (June–July 1945) — convened to discuss the Wavell Plan
4) Cabinet Mission (March–June 1946)

Therefore, the correct sequence is 1, 4, 3, 2.

Explanation:

Correct matching:
– A. Lord Dalhousie (1848–1856) → 4. Doctrine of Lapse: Used to annex states like Satara, Jhansi, Nagpur; hallmark of his expansionist policy.
– B. Lord Curzon (1899–1905) → 3. Partition of Bengal: Implemented in 1905, leading to widespread nationalist agitation and Swadeshi movement.
– C. Lord William Bentinck (1828–1835) → 2. Prohibition of Sati: Abolished sati by Regulation XVII of 1829 in Bengal Presidency.
– D. Lord Cornwallis (1786–1793) → 1. Permanent Settlement of Bengal: Introduced in 1793 (Cornwallis Code), fixing land revenue with zamindars.

Explanation:

Statement 1 is incorrect: Under Part IXA of the Constitution, Article 243V, the minimum age to be chosen as a member of a Municipality is 21 years, not 25 (25 applies to Legislative Assembly/ Lok Sabha).

Statement 2 is correct: Article 243T(3) provides that not less than one-third of the total seats to be filled by direct election in every Municipality shall be reserved for women (including SC/ST women). Some States have increased this to 50%, but the constitutional minimum is one-third. Hence, only Statement 2 is correct. Therefore, Option 3 is right;

Explanation:

Operation Brahma was an Indian humanitarian assistance mission launched in March 2025 specifically to aid Myanmar. Hence, among the listed countries, only Myanmar (statement 2) is correct. 

Explanation:

Highest peaks by state:
– Tamil Nadu: Doddabetta (Nilgiri Hills)
– Rajasthan: Guru Shikhar (Aravalli Range)
– Nagaland: Saramati (Indo-Myanmar border)
– Madhya Pradesh: Dhupgarh (Satpura, near Pachmarhi)

Thus A-2, B-3, C-4, D-1, which matches Option 4.

Explanation:

Assertion (A) is true: Fuse elements should have low melting point and relatively high resistivity so they heat up and melt quickly under overcurrent (I^2R heating). Low-cost domestic fuse wires commonly use a lead–tin (Sn–Pb) alloy for this reason.
Reason (R) is false: Sn–Pb alloys melt around 180–220°C (eutectic ~183°C), which is far below the melting points of copper (~1084°C) and aluminium (~660°C). Hence the claim that the alloy has a higher melting point than copper and aluminium is incorrect.

Thus, Option 3 is correct.