Static Quiz 23 February 2023 (Geography)

Solution: A
Justification: Statement 1: The world’s largest producer of iron ore is the Brazilian mining corporation Vale, followed by Anglo-Australian companies Rio Tinto Group and then BHP Billiton.

Statement 2: Chile is the top producer of copper. The second top producer is China, but the copper mining industry here is nowhere near the production capacity of Chile.

Statement 3: Brazil and Bolivia are among the world’s largest producers of tin. South America also has large deposits of gold, silver, zinc, chromium, manganese, bauxite, mica, platinum, asbestos and diamond. Mineral oil is found in Venezuela, Argentina, Chile, Peru and Columbia.

Solution: C
Justification: Folds form under varied conditions of stress, hydrostatic pressure, pore pressure, and temperature gradient, as evidenced by their presence in soft sediments.

Statement 1: Water pressure from underneath the rocks is tremendous and it can exert differential pressure on the rocks to deform them from one or the other sides causing the formation of a fold.

Statement 2: Temperature gradient can cause elongation of one part and shortening of the other part leading to formation of faults.

Solution: B
Justification: Due to geological changes, molten rocks formed in the deeper hot regions of earth’s crust are pushed upward and trapped in certain regions called ‘hot spots’. When underground water comes in contact with the hot spot, steam is generated. Sometimes hot water from that region finds outlets at the surface. Such outlets are known as hot springs. The steam trapped in rocks is routed through a pipe to a turbine and used to generate electricity. The cost of production would not be much, but there are very few commercially viable sites where such energy can be exploited. There are number of power plants based on geothermal energy operational in New Zealand and United States of America.

Solution: B
Justification: Conditions Favourable for Delta Formation
Active erosion of the river in its upper course to provide extensive gravel, sand, and silt to be eventually deposited as deltas.
The coast should be sheltered preferably tideless, else delta will be washed away.
There should be no strong current running at the right angle to the river mouth, as it can wash away the sediments.
Any large lake in the way or river course can filter off the sediments, thus unfavorable for delta formation.
The sea should be shallowly adjoining the delta as the sediments will disappear in the deep waters of the sea. This is why a continental shelf is preferred.

Solution: B
Justification: Statement 1: River slows down in the lower course which allows the sediments to settle down.
This is opposite to the river’s action in the upper courses where the river mainly erodes.

Statement 2: As the debris or silt is deposited, it reduces the depth available for the water to flow, and thus the bed is raised. Floodplains are created as a result of both erosion and deposition. Material is also deposited on the sides forming raised banks called Levees. When the river reaches the sea, the fine materials it has not dropped yet are deposited at its mouth, forming a fan shaped alluvial area called a delta.