NCERT Solutions For Class 11 Geography Chapter 5 Geomorphic Processes - 2025-26

1. Multiple choice questions.

i. Which one of the following processes is a gradational process?

• (a) Deposition
• (b) Diastrophism
• (c) Volcanism
• (d) Erosion

Answer: (d) Erosion.

ii. Which one of the following materials is affected by hydration process?

• (a) Granite
• (b) Clay
• (c) Quartz
• (d) Salts

Answer: (b) Clay.

iii. Debris avalanche can be included in the category of:

• (a) Landslides
• (b) Slow flow mass movements
• (c) Rapid flow mass movements
• (d) Subsidence

Answer: (c) Rapid flow mass movements.

2. Answer the following questions in about 30 words.

i. It is weathering that is responsible for bio-diversity on the earth. How?

Answer: Weathering breaks down rocks into smaller fragments and forms soil, which provides habitat and nutrients for various plants and organisms. The resulting diversity of soils and environments supports different biomes and, consequently, a high level of biodiversity on Earth.

ii. What are mass movements that are real rapid and perceptible? List.

Answer: Rapid and perceptible mass movements include landslides, debris slides, debris avalanches, rockslides, rockfalls, and slumps. These involve swift downslope movement of rock debris under the direct influence of gravity and are noticeable events.

iii. What are the various mobile and mighty exogenic geomorphic agents and what is the prime job they perform?

Answer: The various exogenic geomorphic agents are running water, wind, glaciers, and waves. Their prime job is to acquire, transport, and deposit earth materials, causing erosion and shaping landforms through processes of degradation and aggradation.

iv. Is weathering essential as a pre-requisite in the formation of soils? Why?

Answer: Yes, weathering is essential for soil formation because it breaks down rocks into smaller fragments, forming regolith. This provides the mineral base upon which further processes, including biological activity, act to create mature soil.

3. Answer the following questions in about 150 words.

i. "Our earth is a playfield for two opposing groups of geomorphic processes." Discuss.

Answer: The earth’s surface is continually shaped by two sets of geomorphic processes: endogenic and exogenic. Endogenic forces, such as diastrophism and volcanism, build up landforms by elevating or creating new features like mountains and plateaus.

In contrast, exogenic forces—including weathering, erosion, mass wasting, and deposition—wear down these reliefs, breaking and transporting materials. The interplay between these constructive (endogenic) and destructive (exogenic) forces means that while new landforms are constantly being formed, others are simultaneously being modified, degraded, or removed.

The dynamic equilibrium between these two sets of processes results in the constantly changing landscape of the earth. This ongoing opposition ensures that no landform remains unchanged forever, giving the planet its diverse range of surface features over time.

ii. Exogenic geomorphic processes derive their ultimate energy from the sun’s heat. Explain.

Answer: Exogenic geomorphic processes such as weathering, mass movements, erosion, and deposition are primarily driven by energy from the sun. Solar radiation is responsible for heating the Earth’s atmosphere and surface, creating temperature differences and pressure gradients.

These drive atmospheric circulation (winds), initiate rainfall and snow, and create surface and subsurface water flows. Additionally, solar energy causes direct expansion and contraction of rocks and influences evaporation, condensation, and the water cycle.

All exogenic agents—wind, water, waves, and glaciers—rely on energy provided by the sun to become mobile and act on earth materials. Thus, while endogenic processes draw energy from within the Earth, exogenic processes ultimately harness solar energy to remodel the earth’s surface.

iii. Are physical and chemical weathering processes independent of each other? If not, why? Explain with examples.

Answer: Physical and chemical weathering processes are not entirely independent; they often work together. Physical weathering breaks rocks into smaller pieces, increasing surface area for chemical reactions.

For example, when rock disintegrates due to temperature changes or pressure release (physical), water and air can more easily infiltrate, allowing chemical reactions like oxidation, hydration, and carbonation to occur (chemical).

Similarly, chemical weathering can weaken minerals and bonds within rocks, making them more susceptible to physical fragmentation. Biological activity can also facilitate both processes simultaneously by producing organic acids (chemical) and disrupting rocks via root growth or burrowing (physical). Thus, in the natural environment, both processes usually operate in tandem to weather rocks.

iv. How do you distinguish between the process of soil formation and soil-forming factors? What is the role of climate and biological activity as two important control factors in the formation of soils?

Answer: The process of soil formation, or pedogenesis, refers to how soils are produced—starting from the weathering of rocks to the development of mature soil profiles with mineral and organic matter.

Soil-forming factors, on the other hand, are the variables influencing this process—namely parent material, topography, climate, biological activity, and time.

Among these, climate is crucial as it determines moisture availability and temperature, controlling the rates of chemical and biological reactions and influencing soil depth, composition, and fertility.

Biological activity (plants, animals, microorganisms) contributes organic matter, decomposes minerals, fixes nitrogen, mixes soil layers, and affects soil texture and chemistry.

Both factors are active controls because they directly determine the nature and rate of soil formation, influencing the properties and productivity of soils.

Master Geomorphic Processes with NCERT Solutions (2025-26)

Dive deep into the world of geomorphic processes like weathering, mass wasting, erosion, and deposition with our updated NCERT Solutions for 2025-26. Understanding these concepts is crucial for building a strong base in Geography.

Explore the factors of soil formation and how different landforms evolve over time. Make use of our well-structured exercise-based solutions to boost your exam performance and command over NCERT Geography chapters.

Regular practice of these NCERT chapter-wise solutions helps clarify core topics and enhances confidence. Focus on key definitions and diagrams to maximize scores in your CBSE board and competitive exams.

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