Some important MCQs related to Geological works by River with Explanations - 2

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1. Which type of erosion is most prominent in the youthful stage of a river?

a) Lateral erosion
b) Vertical erosion
c) Abrasion
d) Solution

Answer: b) Vertical erosion
Explanation:
In the youthful stage, rivers cut downward into their beds, creating steep V-shaped valleys. Vertical erosion dominates as the river tries to reach base level (the lowest point it can erode to).


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2. Which process leads to the formation of braided rivers?

a) High velocity and erosion
b) Deposition due to sediment overload
c) Tectonic uplift
d) Chemical weathering

Answer: b) Deposition due to sediment overload
Explanation:
Braided rivers form when a river carries more sediment than it can transport. This excess sediment is deposited, creating multiple interwoven channels. Such rivers are common in areas with high sediment supply, like glacial or desert regions.



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3. The feature formed by the deposition of sediments along the edges of a river during floods is called:

a) Meander
b) Levee
c) Point bar
d) Delta

Answer: b) Levee
Explanation:
Levees are natural embankments created when a river overflows its banks during floods. Coarse sediments are deposited close to the riverbank, forming raised ridges.

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4. What is the term for the deepest part of a river channel?

a) Thalweg
b) Cut bank
c) Point bar
d) Riverbed

Answer: a) Thalweg
Explanation:
The thalweg is the line of maximum depth and fastest flow within a river channel. It typically follows the outer bends of meanders, where erosion is most intense.



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5. The type of load carried by a river that consists of dissolved minerals is called:

a) Bedload
b) Suspended load
c) Solution load
d) Traction load

Answer: c) Solution load
Explanation:
The solution load consists of minerals dissolved in water, such as calcium carbonate, which are transported invisibly in the river.


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6. What type of landform is created when a river flows over a resistant rock layer followed by a less resistant one?

a) Rapids
b) Waterfall
c) Gorge
d) Canyon

Answer: b) Waterfall
Explanation:
Waterfalls form when a river flows over a harder rock layer that resists erosion, with softer rock eroding more quickly downstream. This creates a vertical drop.
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7. Which river process is responsible for creating ox-bow lakes?

a) Vertical erosion
b) Hydraulic action
c) Meandering and deposition
d) Tectonic uplift

Answer: c) Meandering and deposition
Explanation:
Ox-bow lakes form when a meander becomes too curved and is cut off from the main river. Deposition seals off the old meander loop, creating a separate water body.

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8. What determines the competence of a river?

a) The volume of water it carries
b) The size of particles it can transport
c) The amount of sediment it deposits
d) The length of the river

Answer: b) The size of particles it can transport
Explanation:
The competence of a river refers to its ability to transport sediment of a specific size. Faster and more powerful rivers can carry larger particles like boulders, while slower rivers transport finer materials.


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9. The landform formed by the river at its mouth, where it meets the sea or ocean, is called a:

a) Alluvial fan
b) Delta
c) Estuary
d) Floodplain

Answer: b) Delta
Explanation:
Deltas form at the mouth of a river when it deposits sediment as its velocity decreases upon entering a standing water body like an ocean. Examples include the Ganges-Brahmaputra Delta.

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10. The river stage characterized by maximum deposition is:

a) Youthful stage
b) Mature stage
c) Old stage
d) None of the above

Answer: c) Old stage
Explanation:
In the old stage, a river loses energy and focuses on depositing its load, creating features like floodplains, deltas, and ox-bow lakes.

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