UPSC Static Quiz – Geography : 4 June 2026

Solution: A

• Statement-I is correct. Extensive geological evidence, particularly from radiometric dating of basaltic rock samples collected from the ocean floor, confirms this pattern. The youngest oceanic crust is found at the very crest of the mid-oceanic ridges, and the rocks become progressively older with increasing distance from the ridge axis on either side. The oldest oceanic crust, found near continental margins or trenches, is only about 200 million years old, which is significantly younger than the oldest continental rocks.
• Statement-II is also correct. Mid-oceanic ridges are divergent plate boundaries. Here, convection currents in the Earth’s mantle bring hot, molten magma towards the surface. This magma erupts along the central rift valley, cools, and solidifies to form new oceanic crust. This continuous process of crust formation acts like a conveyor belt, pushing the previously formed crust away from the ridge in both directions.
• Statement-II provides the precise mechanism that causes the phenomenon described in Statement-I.

Solution: B

• Guyot (A) is correctly matched with description 2. A guyot is a type of seamount that has a distinct flat top. The flatness is the result of wave erosion. These structures were once volcanic islands that rose above sea level. Over time, wave action planed off their tops. Subsequently, due to subsidence of the oceanic crust or a rise in sea level, they sank back below the ocean surface. They are also known as tablemounts.
• Atoll (B) is correctly matched with description 3. An atoll is a specific type of coral reef structure. It is characterized by a circular or ring-shaped coral reef that completely or partially encloses a central lagoon. Atolls form from fringing reefs around a volcanic island. As the volcanic island slowly subsides, the coral continues to grow upwards, maintaining its position in the sunlit zone of the ocean. Eventually, the island disappears completely beneath the water, leaving only the ring of coral.
• Submarine Canyon (C) is correctly matched with description 1. Submarine canyons are deep, steep-sided valleys that are cut into the continental shelf and slope. They often resemble major river canyons on land and can be extensions of terrestrial river systems. They are primarily formed by the erosive action of turbidity currents, which are underwater avalanches of sediment-laden water.
• Seamount (D) is correctly matched with description 4. A seamount is a mountain rising from the ocean floor that does not reach the water’s surface (sea level), and thus is not an island. These are typically formed from extinct volcanoes and can be found in all ocean basins. They are hotspots of biodiversity, as they provide a hard substrate for marine life to attach to and can influence local ocean currents.

Solution: D

• Bauxite (1): Bauxite is the primary ore from which aluminum is extracted. Australia (B) has historically been the world’s largest producer of bauxite. The primary industrial use of bauxite is for the production of Aluminium (ii) through the Bayer and Hall-Héroult processes. Therefore, the correct combination is 1-B-ii.
• Cobalt (2): Cobalt is a critical metal for modern technology. The Democratic Republic of Congo (A) dominates global production, accounting for over 70% of the world’s supply. Its most crucial application is in the cathodes of lithium-ion rechargeable batteries (iii) used in electric vehicles, smartphones, and laptops. Therefore, the correct combination is 2-A-iii.
• Rare Earth Elements (REEs) (3): REEs are a group of 17 chemically similar metallic elements. China (C) has long dominated both the mining and processing of these elements. One of their most vital uses is in the manufacturing of powerful permanent high-strength magnets (i) (e.g., neodymium magnets) used in electric vehicle motors, wind turbines, and consumer electronics. Therefore, the correct combination is 3-C-i.

Solution: C

• Statement 1 is correct. Spring tides occur during the new moon and full moon phases, which is when the Sun, Moon, and Earth are aligned (a condition known as syzygy). In this alignment, the gravitational pulls of the Sun and the Moon combine, reinforcing each other. This produces higher-than-average high tides and lower-than-average low tides, leading to the maximum daily tidal range.
• Statement 2 is correct. Neap tides occur when the Sun and Moon are at a right angle to each other relative to the Earth, which happens during the first and third quarter moon phases. In this configuration, the gravitational pull of the Sun partially cancels out the gravitational pull of the Moon. This results in lower-than-average high tides and higher-than-average low tides, leading to the minimum daily tidal range.
• Statement 3 is correct. This statement accurately describes the “equilibrium theory” of tides. The Moon’s gravitational pull creates two tidal bulges on opposite sides of the Earth: one directly facing the Moon and another on the opposite side (due to the interplay of gravity and inertia). These bulges are relatively fixed in space with respect to the Moon. The Earth, however, rotates on its axis once every 24 hours (approximately). As a specific location on the Earth’s surface rotates through these two bulges, it experiences two high tides and two intervening low tides each day (more precisely, every 24 hours and 50 minutes, due to the Moon’s own revolution around the Earth).

Solution: D

• Option (d) is the most accurate and fundamental principle. Weber’s theory posits that the optimal location for a manufacturing plant is the one that minimizes total transportation costs. For an iron and steel plant, the primary raw materials are iron ore and coking coal, both of which are bulky and weight-losing (a significant amount of weight is lost during the smelting process). Therefore, the plant will ideally be located at a point that minimizes the cost of bringing these materials together and shipping the final product to the market. This could be near the coal fields (e.g., Ruhr Valley, Germany), near the iron ore source (e.g., Pittsburgh, USA, historically), or at a coastal port location that can efficiently import both raw materials (e.g., plants in Japan and South Korea).