5th March 2026

Explanation:

• Statement 1 is correct: NAT is a highly sensitive molecular diagnostic technique that detects the genetic material (DNA or RNA) of viruses in donated blood, thereby reducing the "window period" between infection and detectability.
• Statement 2 is correct: Unlike traditional serological tests like ELISA, NAT can identify infections such as HIV, Hepatitis B, and Hepatitis C at very early stages when antibodies may not yet be present.
• Statement 3 is incorrect: NAT has not completely replaced ELISA in India. Many blood banks primarily continue to use ELISA tests, which are less expensive, though comparatively less sensitive during early infection stages.

Explanation:

• Statement 1 is correct: The CWC was established in 1957 under the Warehousing Corporations Act, 1962, tracing its origins to a separate Food Department created in 1942 during World War II.
• Statement 2 is incorrect: CWC's nodal ministry is the Ministry of Consumer Affairs, Food & Public Distribution, not the Ministry of Agriculture & Farmers Welfare.
• Statement 3 is correct: As part of its logistics services, CWC operates Inland Container Depots (ICDs), Container Freight Stations (CFSs), and integrated logistics hubs.

Explanation:

• Point 1 is correct: CWC provides scientific storage through construction and management of warehouses and godowns for foodgrains, sugar, fertilisers, and other commodities.
• Point 2 is correct: CWC assists procurement, buffer stocking, and distribution under the Public Distribution System (PDS).
• Point 3 is incorrect: CWC does not formulate MSP for crops. MSP is determined by the Commission for Agricultural Costs and Prices (CACP) and approved by the Cabinet.
• Point 4 is correct: CWC provides custom bonded warehousing with bonded storage and customs support for import-export trade.

Explanation:

• Statement 1 is incorrect: Oleum is produced by absorbing SO₃ into concentrated sulfuric acid (H₂SO₄) through the Contact Process — specifically to avoid directly dissolving SO₃ in water, which would create an uncontrollable sulfuric acid mist.
• Statement 2 is correct: Oleum is represented as H₂SO₄·xSO₃. When x = 1, the compound is Disulfuric Acid (H₂S₂O₇), also known as Pyrosulfuric Acid.
• Statement 3 is correct: Oleum is used in preparing nitration mixtures for manufacturing explosives such as Trinitrotoluene (TNT) and for secondary nitration reactions like nitration of nitrobenzene.

Explanation:

• Statement 1 is correct: Shtil is a ship-based surface-to-air missile (SAM) system designed to intercept aircraft, helicopters, anti-ship missiles, and other aerial threats targeting naval vessels, providing medium-range air defence in maritime environments.
• Statement 2 is incorrect: Shtil was developed by Russian defence industries, derived from the Buk family of air defence missiles. Exports are managed by JSC Rosoboronexport — it is not an indigenous Indian system developed by DRDO.
• Statement 3 is correct: It features a Vertical Launch System (VLS) that enables missiles to be launched quickly in multiple directions without rotating launchers, providing rapid reaction against incoming aerial threats.