UPSC CDS-2 Archives

1. Which of the following states is/are part of the Ganga Basin ? 1. Ch

Which of the following states is/are part of the Ganga Basin ?

1. Chhattisgarh
2. Himachal Pradesh
3. Rajasthan

Select the answer using the code given below :

1 only

1 and 2 only

2 and 3 only

1, 2 and 3

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UPSC CDS-2 – 2024

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The Ganga River Basin is one of the largest river basins in the world, covering vast areas of India, Nepal, Bangladesh, and parts of China. In India, the basin encompasses numerous states.
– Statement 1: Chhattisgarh is partly drained by the Son River, which is a major southern tributary of the Ganga. Thus, Chhattisgarh is part of the Ganga Basin.
– Statement 2: Himachal Pradesh is part of the upper Ganga basin as some of the tributaries of the Yamuna (which is a major tributary of the Ganga) originate or flow through the state.
– Statement 3: Rajasthan is part of the Ganga basin through tributaries like the Chambal River, which is a major tributary of the Yamuna.
Therefore, Chhattisgarh, Himachal Pradesh, and Rajasthan are all states that are part of the vast Ganga Basin system.

– The Ganga basin covers multiple Indian states and neighboring countries.
– Major tributaries like Yamuna and Son expand the basin’s reach to states beyond the direct course of the Ganga.
– Chhattisgarh (Son), Himachal Pradesh (Yamuna tributaries), and Rajasthan (Chambal tributary) are part of the basin.

Other major states included in the Ganga basin within India are Uttarakhand, Uttar Pradesh, Bihar, Jharkhand, West Bengal, Haryana, Delhi, and parts of Madhya Pradesh. The basin is geographically diverse, ranging from the Himalayas in the north to the delta in the south.

2. Which one of the following statements regarding S-waves is not corre

Which one of the following statements regarding S-waves is not correct ?

S-waves are slower than P-waves.

During an earthquake S-waves are less destructive to structures like buildings and highway overpasses.

S-waves can travel only through solids and cannot travel through the Earth's outer core.

Seismologists have concluded that the Earth's outer core must be liquid or fluid.

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Statement A is correct. P-waves (primary waves) are compressional waves and travel faster through the Earth’s layers than S-waves (secondary waves), which are shear waves. P-waves are the first to arrive at a seismic station.

Statement B is incorrect. S-waves cause particles to move perpendicular to the direction of wave propagation, resulting in a shearing motion. This sideways and vertical shaking motion is generally more damaging and destructive to structures like buildings, bridges, and overpasses compared to the push-pull motion of P-waves.

Statement C is correct. S-waves can only travel through solid materials because they rely on the rigidity of the medium to transmit the shear force. Liquids and gases have no rigidity, so S-waves cannot propagate through them. The Earth’s outer core is known to be liquid.

Statement D is correct. The observation that S-waves generated by earthquakes do not pass through the Earth’s outer core is the primary seismological evidence indicating that the outer core is in a liquid or fluid state.

– S-waves are slower than P-waves.
– S-waves are generally more destructive than P-waves due to their shearing motion.
– S-waves cannot travel through liquids.
– The absence of S-waves in the outer core indicates it is liquid.

Seismology, the study of earthquakes and seismic waves, is the main tool used by geophysicists to understand the internal structure and composition of the Earth. P-waves can travel through solids, liquids, and gases, albeit at different speeds.

3. Which of the following statements regarding Arc Volcanoes is/are corre

Which of the following statements regarding Arc Volcanoes is/are correct ?

1. Arc volcanoes are found near divergent plate boundaries.
2. Some of the world’s classical examples of cone-shaped stratovolcanoes, such as Mount Fuji in Japan, Mayon in the Philippines are Arc volcanoes.
3. Some of the highest volcanoes on Earth are of the Arc type, notably Nevado Ojos del Salado in the Chilean Andes.

Select the answer using the code given below :

2 only

2 and 3 only

1 and 3 only

1, 2 and 3

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Statement 1 is incorrect. Arc volcanoes are typically found near convergent plate boundaries, where one tectonic plate subducts beneath another. This process leads to the melting of the mantle wedge above the subducting plate, generating magma that rises to the surface to form volcanoes in an arc shape parallel to the plate boundary. Divergent plate boundaries are associated with rift volcanism (like mid-ocean ridges) or flood basalts.

Statement 2 is correct. Volcanic arcs are known for producing explosive eruptions and building steep-sided, cone-shaped composite volcanoes (stratovolcanoes). Mount Fuji in Japan and Mount Mayon in the Philippines are indeed famous examples of stratovolcanoes located in the Pacific Ring of Fire, which is largely composed of volcanic arcs formed by subduction.

Statement 3 is correct. Volcanic arcs, particularly those associated with continental collision or significant crustal thickening, can host very high volcanoes. The Andes mountain range in South America is a classic example of a volcanic arc formed by the subduction of the Nazca Plate beneath the South American Plate. Nevado Ojos del Salado, located in the Chilean Andes, is one of the highest volcanoes in the world (and the highest active volcano).

– Arc volcanoes form at convergent plate boundaries (subduction zones).
– Stratovolcanoes like Fuji and Mayon are characteristic of volcanic arcs.
– High volcanoes, including Nevado Ojos del Salado, are found in some volcanic arcs like the Andes.

Volcanic arcs can be either continental (formed on the edge of a continent) or oceanic (forming a chain of volcanic islands). The shape of the arc is related to the curvature of the Earth and the angle of subduction.

4. Which one of the following is not an example of chemical weathering

Which one of the following is not an example of chemical weathering ?

Acid action

Hydrolysis

Salt Crystal Growth

Oxidation

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Chemical weathering involves processes that change the chemical composition of rocks and minerals. Acid action (like carbonation, where carbonic acid dissolves minerals), Hydrolysis (reaction of water with minerals), and Oxidation (reaction with oxygen) are all examples of chemical weathering. Salt Crystal Growth (also known as salt weathering or haloclasty) is a process where salt crystals grow in pores and cracks within rocks, exerting pressure that forces the rock apart. This is a physical process that breaks down the rock without changing its chemical composition, making it an example of physical or mechanical weathering, not chemical weathering.

Weathering is the breakdown of rocks, soil, and minerals through contact with the Earth’s atmosphere, water, and biological organisms. It is broadly classified into physical (mechanical), chemical, and biological weathering.

Salt weathering is particularly effective in arid and coastal environments where evaporation leads to the crystallization of dissolved salts within the rock pores.

5. How is strong pressure gradient represented on a weather map ?

How is strong pressure gradient represented on a weather map ?

Closely spaced isobars

Widely spaced isobars

Closely spaced isobars at the periphery

A set of two widely spaced isobars followed by two closely spaced isobars

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On a weather map, isobars are lines connecting points of equal atmospheric pressure. The pressure gradient is the rate of change of pressure over a horizontal distance. A strong pressure gradient indicates a large change in pressure over a short distance, which results in high wind speeds. On a weather map, this is visually represented by isobars that are drawn very close together. Conversely, widely spaced isobars indicate a weak pressure gradient and light winds.

The pressure gradient force is one of the primary forces driving wind. It acts perpendicular to isobars, from areas of high pressure to areas of low pressure.

The closer the isobars, the stronger the pressure gradient, and consequently, the stronger the pressure gradient force and potentially higher wind speeds (though other factors like the Coriolis effect and friction also influence wind).

6. As per India State of Forest Report 2021, which one of the following s

As per India State of Forest Report 2021, which one of the following states is not among the top three with reference to maximum area under forest ?

Arunachal Pradesh

Chhattisgarh

Madhya Pradesh

Maharashtra

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According to the India State of Forest Report (ISFR) 2021, the top three states in terms of the largest forest area are Madhya Pradesh, Arunachal Pradesh, and Chhattisgarh. The states listed in the options are Arunachal Pradesh, Chhattisgarh, Madhya Pradesh, and Maharashtra. Maharashtra is listed in the options but is not among the top three states by forest area according to the ISFR 2021; it is typically ranked lower, often 4th or 5th.

The India State of Forest Report (ISFR), published biennially by the Forest Survey of India (FSI), provides estimates of forest cover, tree cover, and related data at the national, state, and district levels.

It is important to distinguish between forest area (total area covered by forest) and forest cover as a percentage of geographical area. The ISFR 2021 also lists states with the largest percentage of geographical area under forest cover, which are primarily in the Northeast and Andaman & Nicobar Islands.

7. Consider the following statements: 1. Ocean currents are dominated b

Consider the following statements:

1. Ocean currents are dominated by huge surface gyres that are driven by the global surface wind pattern.
2. Equatorial currents move cold water westward and then poleward along the east coasts of continents.

With regard to the statements given above, which of the following is correct ?

Both the statements are correct and statement 2 is the correct explanation of statement 1.

Both the statements are correct, but statement 2 is not the correct explanation of statement 1.

Statement 1 is correct, but statement 2 is false.

Statement 1 is false, but statement 2 is correct.

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Statement 1 is correct: The primary driving force for large-scale surface ocean currents are the prevailing winds, which exert friction on the water surface. These wind-driven currents are organized into large, rotating patterns called gyres in the major ocean basins. Statement 2 is incorrect: Equatorial currents are typically driven by the trade winds and flow westward. However, these equatorial currents carry *warm* water away from the equator. When these currents reach the western boundary of an ocean basin, they turn poleward along the east coasts of continents, forming major *warm* currents like the Gulf Stream in the Atlantic and the Kuroshio Current in the Pacific. Cold currents typically flow poleward along the *west* coasts of continents (e.g., California Current).

Surface ocean currents are largely driven by wind and the Coriolis effect, forming gyres. Warm currents generally flow from the tropics towards the poles, while cold currents flow from higher latitudes towards the equator.

Ocean gyres typically consist of a westward-flowing equatorial current, a poleward-flowing warm current along the western boundary, an eastward-flowing current in the mid-latitudes, and an equatorward-flowing cold current along the eastern boundary.

8. Consider the following statements : 1. Hadley cells are key to under

Consider the following statements :

1. Hadley cells are key to understanding the wind patterns of Earth.
2. Hadley cells are formed because the Equator is heated more strongly by the Sun than other places, creating thermal circulations.

With regard to the statements given above, which of the following is correct ?

Both the statements are correct and statement 2 is the correct explanation of statement 1.

Both the statements are correct, but statement 2 is <i>not</i> the correct explanation of statement 1.

Statement 1 is correct, but statement 2 is false.

Statement 1 is false, but statement 2 is correct.

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Statement 1 is correct: Hadley cells are fundamental atmospheric circulation patterns in the tropics and are essential for understanding the global distribution of pressure belts and wind patterns like the trade winds and the intertropical convergence zone (ITCZ). Statement 2 is correct: Hadley cells are indeed formed due to the differential heating of the Earth’s surface. The equatorial region receives the most direct solar radiation, causing air to heat up, become less dense, and rise (convection). This rising warm air then flows poleward at high altitudes, cools, sinks around 30 degrees latitude, and returns towards the equator as surface winds (trade winds), completing the circulation loop. This thermal driving force directly explains the formation and function of Hadley cells, which, in turn, dictates tropical wind patterns. Thus, statement 2 is the correct explanation for statement 1.

Hadley cells are part of the general atmospheric circulation model, driven by latitudinal variations in solar radiation.

Beyond the Hadley cells (0-30 degrees), there are also Ferrel cells (30-60 degrees) and Polar cells (60-90 degrees), which contribute to the global pattern of atmospheric circulation and winds. However, the Hadley cells are the most thermally direct and dominant circulation feature in the tropics.

9. Which kind of mass wasting processes are commonly associated with cree

Which kind of mass wasting processes are commonly associated with creep ?

Fast speed with soil

Slow speed with rock

Slow speed with ice

Slow speed with soil

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Creep is a type of mass wasting characterized by the slow, gradual, and continuous movement of soil or regolith down a slope. It typically occurs over long periods and is often imperceptible except through observations of its effects, such as tilted poles, fences, or tree trunks. It is predominantly associated with the slow movement of unconsolidated material like soil.

Mass wasting processes are classified based on the type of material, speed, and nature of movement. Creep is the slowest form of mass wasting involving soil or regolith.

Other types of mass wasting include flows (like mudflows, debris flows – faster, involving water), slides (rockslides, landslides – movement along a plane), and falls (rockfalls – free-fall of material). Creep is influenced by factors like freeze-thaw cycles, wetting and drying of soil, and animal activity.

10. Eratosthenes, a Greek philosopher measured the Earth’s circumference b

Eratosthenes, a Greek philosopher measured the Earth’s circumference based on the angle of Sun rays at two different points. Which cities were they ?

Alexandria and Syene

Syene and Troy

Alexandria and Troy

Alexandria and Thebes

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The Greek mathematician, geographer, and astronomer Eratosthenes is famous for calculating the circumference of the Earth around 240 BC. He did this by observing the angle of the sun’s rays at noon on the summer solstice in two different Egyptian cities, Syene (modern Aswan), where the sun was directly overhead (no shadow in a well), and Alexandria, where the sun’s rays cast a shadow at a measurable angle. He then used the distance between the two cities and basic geometry to estimate the Earth’s circumference.

Eratosthenes was one of the first to accurately estimate the size of the Earth using geometrical principles and astronomical observations.

Syene is located close to the Tropic of Cancer. On the summer solstice, the sun is directly overhead at noon along the Tropic of Cancer. Alexandria is located north of the Tropic of Cancer, so the sun would not be directly overhead there. The difference in the angle of the sun’s rays at the two locations allowed Eratosthenes to calculate the curvature of the Earth and subsequently its circumference.