UPSC Static Quiz – Geography : 19 March 2026

Solution: B

• Statement-I is Correct: It defines the fundamental difference between “space climate” and “space weather.” The Solar Wind is always present, flowing at ~400 km/s. A CME is a specific event, often associated with solar flares, where a billion tons of plasma is hurled into space at speeds up to 3,000 km/s.
• Statement-II is Correct: While the solar wind causes background aurorae and minor disturbances, the catastrophic G5-level storms (like the Carrington Event or the May 2024 storm) are almost exclusively caused by the impact of a directed CME. The CME carries its own magnetic field, which, if oriented opposite to Earth’s field, allows massive energy transfer into our magnetosphere.
• Statement-II explains the impact of CMEs, but it does not explain the definition or distinction presented in Statement-I. Statement-I is about what they are; Statement-II is about what they do.

Solution: D

• Statement I is incorrect. Limestone landscapes are not predominantly shaped by physical weathering such as block disintegration. Block disintegration is typically associated with mechanically weathered, well-jointed rocks in arid or semi-arid climates where large diurnal temperature variations cause repeated expansion and contraction. Limestone terrains, by contrast, are classic examples of chemical weathering-dominated landscapes, especially under humid climatic conditions.
• Statement II is correct. Rainwater absorbs carbon dioxide from the atmosphere and soil to form carbonic acid, a weak acid. This acid reacts with calcium carbonate present in limestone through the process of carbonation, converting it into calcium bicarbonate, which is soluble in water. Continuous dissolution leads to distinctive landforms such as sinkholes, dolines, caves, and underground drainage systems, collectively known as karst topography. This chemical process, rather than physical breakdown, is the principal agent shaping limestone regions over geological timescales.

Solution: C

• Subsidence inversion is caused by large-scale sinking of air in high-pressure belts, especially in the subtropical horse latitudes. As air descends, it undergoes adiabatic compression and warming, creating a warm layer aloft that suppresses vertical convection; this explains its association with arid trade desert regions.
• Radiation inversion develops due to rapid terrestrial heat loss during clear, calm nights, particularly in winter. The ground cools faster than the overlying air, leading to colder air near the surface and warmer air above, often resulting in ground fog and frost.
• Advection inversion occurs when warm, moist air moves horizontally over a colder surface, such as warm air flowing over cold ocean currents like the Labrador or California Current, cooling the lower air layer and producing fog. Each mechanism and characteristic aligns precisely with its respective inversion type.

Solution: A

• The characteristic green color of the aurora is produced by atomic oxygen present in the Earth’s upper atmosphere, particularly in the thermosphere at altitudes of roughly 100–300 km. When charged particles (mainly electrons) emitted by the Sun are guided by Earth’s magnetic field toward the polar regions, they collide with atmospheric gases. These collisions excite the atoms by raising their electrons to higher energy states.

Solution: B

1. Gulf of Kutch (Gujarat):Found.Contains patchy fringing reefs, though they are under high stress from salinity and sedimentation. They are the northernmost reefs in India.
2. Gulf of Khambhat (Gujarat):Not Found.This region receives massive freshwater and sediment discharge from rivers like Narmada and Tapi. The high turbidity and low salinity prevent coral growth.
3. Gulf of Mannar (Tamil Nadu):Found.A Biosphere Reserve with rich fringing reef biodiversity.

4. Sunderbans (West Bengal): Not Found. The world’s largest mangrove delta. The immense freshwater outflow from the Ganges-Brahmaputra and extreme siltation make it impossible for corals to survive.