2nd January 2025

Explanation: Statements 1 and 3 are correct, while 2 and 4 are incorrect.
Statement 1 is correct; the Smart Cities Mission aims to enhance quality of life in 100 selected cities through efficient services and sustainable infrastructure.
Statement 2 is incorrect; the mission follows a bottom-up approach with cities as equal partners in policy formulation, not a top-down approach.
Statement 3 is correct; the mission has led to a 22% increase in student enrollment from 2015-16 to 2023-24 in 19 smart cities.
Statement 4 is incorrect; while ICCCs have been established in many smart cities, they are not present in all 100 cities.

Explanation: Statements 2, 3, and 4 are correct, while statement 1 is incorrect.
Statement 1 is incorrect; oil pollution can also result from natural seeps, land-based sources, and deliberate operational discharges.
Statement 2 is correct; oil slicks form when oil floats on saltwater and spreads rapidly across the water surface.
Statement 3 is correct; bioremediation techniques like Oilzapper and Oilivorous-S are used for cleaning oil spills.
Statement 4 is correct; MARPOL was established in 1978 to address pollution from ships, including oil pollution.

Explanation: Statements 2 and 4 are correct, while 1 and 3 are incorrect.
Statement 1 is incorrect; GLO is a secondary pollutant formed through atmospheric reactions, not a primary pollutant.
Statement 2 is correct; NOx and VOCs are major precursor pollutants for GLO formation.
Statement 3 is incorrect; peak ozone levels typically occur during summer months, not winter.
Statement 4 is correct; CPCB has set an 8-hour average limit of 100 micrograms per cubic meter for GLO.

Explanation: Statements 2 and 3 are correct, while 1 and 4 are incorrect.
Statement 1 is incorrect; ANEEL is designed for use in Pressurised Heavy Water Reactors (PHWRs), not Light Water Reactors.
Statement 2 is correct; ANEEL fuel combines thorium with small amounts of enriched uranium.
Statement 3 is correct; it reduces nuclear waste generation by over 85% through high burnup fuel performance.
Statement 4 is incorrect; the spent fuel from ANEEL is non-weaponizable due to its thorium content, not highly weaponizable.

Explanation: Statements 1, 3, and 4 are correct, while statement 2 is incorrect.
Statement 1 is correct; MHWs occur when the surface temperature rises to 3 or 4 degrees Celsius above average for at least five days.
Statement 2 is incorrect; advection tends to create deeper and longer-lasting MHWs compared to surface heat flux.
Statement 3 is correct; the number of MHW events has doubled since 1982.
Statement 4 is correct; MHWs have increased by up to four-fold in the tropical Indian Ocean, aided by rapid warming and strong El Niños.