Some important MCQs related to Geological works by Wind With Explanations -2

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11. What is the term used for a large, flat area of desert covered with a surface of closely packed, interlocking angular or rounded rock fragments?

A) Playa
B) Desert pavement
C) Sand dune
D) Alluvial fan

Answer: B) Desert pavement
Explanation:
Desert pavement forms through the process of deflation, where finer particles are blown away, leaving behind a layer of coarse rock fragments that act as a protective surface against further wind erosion.


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12. The process by which fine dust particles are carried long distances by the wind is called:

A) Traction
B) Saltation
C) Suspension
D) Creep

Answer: C) Suspension
Explanation:
Suspension occurs when fine particles, such as silt and clay, are lifted into the air and carried over long distances by the wind. This is common in arid regions with loose, dry soil.


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13. Which of the following is NOT a factor affecting wind erosion?

A) Soil texture
B) Vegetation cover
C) Elevation
D) Wind speed

Answer: C) Elevation
Explanation:
Wind erosion is influenced by soil texture, vegetation cover, and wind speed, but elevation does not directly affect the erosion process unless it influences wind patterns.


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14. What is the main difference between a barchan and a transverse dune?

A) Barchans are formed in the absence of wind, while transverse dunes are formed by strong winds.
B) Barchans are crescent-shaped, while transverse dunes are linear ridges.
C) Barchans form in areas with abundant sand, while transverse dunes form in areas with limited sand.
D) Barchans are crescent-shaped and form in areas with limited sand, while transverse dunes form perpendicular to wind direction in areas with abundant sand.

Answer: D) Barchans are crescent-shaped and form in areas with limited sand, while transverse dunes form perpendicular to wind direction in areas with abundant sand.
Explanation:
Barchans form where sand supply is limited, and wind direction is consistent. Transverse dunes, on the other hand, form in areas with abundant sand and are oriented perpendicular to the wind.


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15. What is a "Lag deposit"?

A) A sedimentary deposit left behind by glaciers
B) Coarse material left after finer particles are removed by wind
C) A sand dune formed in the desert
D) A deposit formed by underwater currents

Answer: B) Coarse material left after finer particles are removed by wind
Explanation:
Lag deposits consist of coarse materials such as pebbles or gravel left behind after wind removes finer particles through deflation. These deposits often contribute to the formation of desert pavements.


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16. Which of the following is an erosional feature of wind?

A) Sand dune
B) Loess deposit
C) Mushroom rock
D) Playa

Answer: C) Mushroom rock
Explanation:
Mushroom rocks, or pedestal rocks, are formed by wind abrasion where the base of a rock is eroded more than the top due to sand particles being concentrated near the ground.


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17. What is the minimum wind speed generally required to initiate sand movement?

A) 2 m/s
B) 5 m/s
C) 10 m/s
D) 20 m/s

Answer: B) 5 m/s
Explanation:
A wind speed of around 5 m/s is typically required to overcome the resistance of sand grains and initiate their movement, such as rolling or saltation.


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18. Which of the following statements about Yardangs is true?

A) They form in areas with abundant vegetation.
B) They are depositional landforms.
C) They form parallel to the prevailing wind direction.
D) They are composed entirely of loess.

Answer: C) They form parallel to the prevailing wind direction.
Explanation:
Yardangs are erosional features formed by wind abrasion in arid regions. They are elongated ridges aligned parallel to the prevailing wind direction.

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19. What causes the steep slip face on the leeward side of a sand dune?

A) Deflation
B) Wind velocity increases
C) Accumulation of sand beyond the angle of repose
D) High soil moisture content

Answer: C) Accumulation of sand beyond the angle of repose
Explanation:
The slip face forms when sand is deposited on the leeward side and exceeds the angle of repose (usually around 30–34°), causing it to slide down and create a steep slope.


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20. The term "Aeolian processes" refers to:

A) Processes related to glacier movement
B) Processes caused by wind
C) Processes caused by river erosion
D) Processes involving volcanic activity

Answer: B) Processes caused by wind
Explanation:
Aeolian processes involve the erosion, transport, and deposition of materials by wind, commonly observed in arid and semi-arid environments.


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