UPSC Static Quiz – Geography : 15 May 2026

Solution: D

• Statement 1 is correct; the region is estimated to contain more than half of the world’s lithium, essential for the global electric vehicle battery market.
• Statement 2 is correct; it encompasses the tri-border area of Argentina, Bolivia, and Chile.
• Statement 3 is correct; unlike the hard-rock lithium mining in Australia, the Triangle’s lithium is found in concentrated brines beneath the Salars (salt flats), such as the Salar de Uyuni (Bolivia) and Salar de Atacama (Chile).
• Economic extraction involves pumping the brine into large evaporation ponds, a process that is less energy-intensive than hard-rock mining but raises significant environmental concerns regarding water usage in an already arid region. Lithium’s role as the “white gold” of the 21st century makes this region a geostrategic focus for India’s energy security.

Solution: A

• Mediterranean Climate: This climate is famous for its distinct seasonal precipitation pattern of dry summers and wet winters. This is caused by the seasonal shift of the subtropical high-pressure belts. In summer, the high-pressure belt moves over the region, causing dry conditions. In winter, the belt shifts towards the equator, allowing mid-latitude cyclones to bring rain. The Köppen code for this climate is Cs (‘s’ for summer dry). Thus, A matches with 3 and ii.
• Tropical Monsoon Climate: This climate is characterized by a seasonal reversal of winds, leading to extremely heavy rainfall during the wet season and a distinct, albeit short, dry season. It supports a monsoon forest rather than a true rainforest. The Köppen code is Am (‘m’ for monsoon). Thus, B matches with 1 and i.
• Subarctic Climate: Also known as the Taiga or Boreal climate, this region is found in the high latitudes of the Northern Hemisphere. It is defined by extremely long, cold, and harsh winters, with short, mild to cool summers. It is a continental climate with the largest annual temperature ranges on Earth. The Köppen code is Dfc (‘D’ for continental, ‘f’ for year-round precipitation, ‘c’ for cool summer). Thus, C matches with 2 and iii.

Solution: A

• Statement-I is correct. The Gandak River, along with the Kosi, is one of the major rivers responsible for recurrent and severe flooding in the northern plains of Bihar. Its unpredictable nature causes widespread damage to life, property, and agriculture in the region.
• Statement-II is correct. The Gandak originates in the high Himalayas in Nepal. Being a river in its youthful stage flowing through geologically young and unstable mountains, it has a very high rate of erosion. Consequently, it carries a massive amount of silt and sediment.
• When the river descends from the mountains and enters the flat, low-gradient Gangetic plains, its velocity decreases drastically. This forces it to deposit its heavy sediment load within its own channel, leading to the formation of levees and raising its riverbed. This process makes the river prone to breaching its banks and changing its course (avulsion) during periods of high discharge.
• Statement-II provides the complete geomorphological explanation for the phenomenon described in Statement-I. The high sediment load and the tendency to change course are the direct physical reasons why the Gandak River causes such frequent and devastating floods. Therefore, Statement-II is the correct explanation for Statement-I.

Solution: C

• Metamorphic Rock are rocks formed when pre-existing rocks undergo transformation due to intense heat, pressure, or chemically active fluids inside the Earth. The original rock from which a metamorphic rock forms is called the parent rock or protolith.
• Marble is a metamorphic rock formed from the sedimentary rock limestone. Limestone mainly consists of calcium carbonate. When subjected to high temperature and pressure during metamorphism, the calcite crystals in limestone recrystallize to form marble. This process gives marble its characteristic hardness, crystalline texture, and decorative appearance. Therefore, marble is an example of a metamorphic rock derived from a sedimentary parent rock.

Solution: B

• Statement I is correct. A Yardang is an aeolian (wind-eroded) landform created in arid and semi-arid regions. It develops where alternating bands of hard and soft rocks are arranged vertically and aligned parallel to the prevailing wind direction. Due to differential erosion, the softer rock is removed more rapidly while the harder rock remains as elongated ridges separated by grooves or corridors. Yardangs are typically streamlined and oriented in the direction of dominant winds.
• Statement II is also correct. A Zeugen is formed in regions with horizontal layers of hard and soft rocks. Wind abrasion erodes the softer underlying layers more rapidly than the resistant upper layer. Over time, this process produces flat-topped or pedestal-like structures, sometimes resembling mushroom rocks or table rocks. Zeugen formation is also associated with thermal weathering and sand-laden winds in desert environments.
• However, Statement II does not explain Statement I because the two statements describe different aeolian landforms formed under different geological arrangements. Yardangs develop mainly in vertically arranged rock strata aligned with prevailing winds, whereas zeugens form in horizontally bedded rocks with resistant cap layers.