NCERT Solutions for Class 11 Geography Chapter 5: Geomorphic Processes (NCERT 2026–27)
These Class 11 Geography Chapter 5 solutions cover Geomorphic Processes from Fundamentals of Physical Geography, the opening chapter of Unit III “Landforms”. The chapter explains why the earth’s surface is uneven, how endogenic (land-building) and exogenic (land-wearing) forces work, and how the denudational processes of weathering, mass movements, erosion and deposition — together with soil formation — reshape the land over very long periods. Below you will find step-by-step answers to every NCERT exercise question, key terms, extra practice, MCQs, Assertion–Reason and FAQs, all updated for the 2026–27 session.
Class: 11Subject: GeographyBook: Fundamentals of Physical GeographyUnit: III – LandformsChapter: 5 – Geomorphic ProcessesSession: 2026–27
Chapter 5, Geomorphic Processes, describes the physical and chemical actions that shape the earth’s surface. The earth’s crust is dynamic, so endogenic forces (driven by energy from within — radioactivity, tidal friction and primordial heat) build up the surface through diastrophism (orogeny, epeirogeny, earthquakes, plate tectonics) and volcanism. Opposing them are exogenic forces, powered ultimately by the sun, which wear the surface down through denudation — weathering, mass movements, erosion and transportation. Weathering (chemical, physical and biological) breaks rocks in situ and prepares regolith for erosion, mass wasting and soil formation, and even enriches valuable ores. Mass movements (creep, flow, slide, fall such as landslides, slump and rockfall) shift debris downslope under gravity, while erosion by running water, wind, glaciers, waves and groundwater removes and transports material, and deposition fills depressions. The chapter ends with soil formation and its five controlling factors: parent material, topography, climate, biological activity and time.
Key Concepts & Terms
Geomorphic processes: the endogenic and exogenic forces that cause physical stresses and chemical actions on earth materials and bring about changes in the configuration of the earth’s surface.
Geomorphic agent: a mobile medium of nature — running water, groundwater, glaciers, wind, waves and currents — that removes, transports and deposits earth materials.
Endogenic processes: internal, land-building processes powered by energy from within the earth — diastrophism (orogeny, epeirogeny, earthquakes, plate tectonics) and volcanism.
Diastrophism: all processes that move, elevate or build up portions of the crust. Orogeny is mountain building by severe folding of narrow belts; epeirogeny is uplift or warping of large parts (continent building).
Exogenic processes / Denudation: external, land-wearing processes powered ultimately by the sun — weathering, mass wasting/movements, erosion and transportation. ‘Denude’ means to strip off or uncover.
Gradation: the wearing down of relief variations through erosion, balanced by aggradation (filling up) of basins.
Weathering: the mechanical disintegration and chemical decomposition of rocks in situ (on-site) through elements of weather and climate. The three groups are chemical, physical/mechanical and biological.
Chemical weathering: solution, carbonation, hydration, oxidation and reduction that decompose or dissolve rocks. Physical weathering: processes such as thermal expansion, pressure release, crystal growth and wetting–drying that fracture rock. Biological weathering: addition/removal of minerals and physical change due to growth or movement of organisms.
Exfoliation: the flaking off of curved sheets/shells from bedrock, giving smooth rounded surfaces; it is a result, not a process.
Mass movements: the transfer of rock debris downslope under the direct influence of gravity, with no geomorphic agent (water, ice, wind) carrying it — including creep, flow, slide and fall (landslides, slump, debris slide, debris fall, rockslide, rockfall).
Erosion & Deposition: erosion is the acquisition and transportation of rock debris by agents (running water, groundwater, glaciers, wind, waves); deposition is the settling of that material when the agent loses velocity — coarser material first, finer later.
Soil & Pedogenesis: soil is a dynamic mixture of mineral and organic matter; its formation (pedogenesis) is controlled by parent material, topography, climate, biological activity and time. Pedology is soil science.
NCERT Exercises — Full Solutions
All questions below are reproduced verbatim from the NCERT textbook’s end-of-chapter Exercises. Answers are original, written in exam-ready style.
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. Gradation is the wearing down of relief variations of the earth’s surface through erosion. Diastrophism and volcanism are endogenic (land-building) processes, while deposition is aggradational; erosion is the classic degradational, i.e. gradational, process.
(ii) Which one of the following materials is affected by hydration process?
(a) Granite (b) Clay (c) Quartz (d) Salts
ANSWER(d) Salts. Hydration is the chemical addition of water to minerals, which makes them swell and increase in volume. Salts (and minerals such as calcium sulphate or certain clays formed from feldspars) readily absorb water and expand, exerting stress that disintegrates the rock. Quartz is highly resistant to hydration.
(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. A debris avalanche is a very fast, water-saturated flow of rock debris down a steep slope. Because the material moves swiftly as a flow rather than sliding as a coherent block, it is classed under 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?
ANSWERWeathering breaks rocks and forms the deep weathering mantle on which regolith and soils develop. Forests and vegetation depend on this depth of weathered material, and since biomes and biodiversity rest on forests, weathering ultimately sustains biodiversity.
(ii) What are mass movements that are real rapid and perceptible? List.
ANSWERThe rapid and perceptible mass movements are landslides, which include: slump (backward-rotational slip), debris slide, debris fall, rockslide and rockfall. The materials involved are relatively dry and move swiftly down steep slopes.
(iii) What are the various mobile and mighty exogenic geomorphic agents and what is the prime job they perform?
ANSWERThe mobile exogenic geomorphic agents are running water, groundwater, glaciers, wind, and waves & currents. Their prime job is to acquire, erode, transport and deposit earth materials, thereby wearing down relief and reshaping the earth’s surface.
(iv) Is weathering essential as a pre-requisite in the formation of soils? Why?
ANSWERYes. Soil formation (pedogenesis) depends first on weathering; the weathering mantle — the depth of weathered material — is the basic input from which soil forms. Without weathered material or transported deposits, organisms cannot colonise and soil cannot develop.
3. Answer the following questions in about 150 words.
(i) “Our earth is a playfield for two opposing groups of geomorphic processes.” Discuss.
ANSWERThe earth’s surface is continuously shaped by two opposing groups of geomorphic processes — endogenic and exogenic. Endogenic forces draw their energy from within the earth (radioactivity, rotational and tidal friction and primordial heat). They are essentially land-building forces: through diastrophism (orogeny, epeirogeny, earthquakes, plate tectonics) and volcanism they elevate, fold, fault and build up portions of the crust, producing relief variations.Exogenic forces, powered ultimately by solar energy and gravity, are land-wearing forces. Through denudation — weathering, mass movements, erosion and transportation — they wear down (degrade) elevations and fill up (aggrade) depressions, smoothing out the relief.These two groups act in opposition: while endogenic forces keep raising and roughening the surface, exogenic forces keep levelling it. Because the actions never stop, relief variations persist as long as the “tug of war” between the two continues — making the earth a true playfield for opposing processes.
(ii) Exogenic geomorphic processes derive their ultimate energy from the sun’s heat. Explain.
ANSWERExogenic processes operate at and near the earth’s surface, and their driving energy comes mainly from the atmosphere, which is itself powered by the sun. The sun’s heat is unevenly received across latitudes and seasons, creating differences in temperature and pressure. These differences set the atmosphere in motion, producing winds, precipitation and climatic variations.Temperature and precipitation — the two key climatic elements — control weathering, mass movements and erosion. Solar heating drives the hydrological cycle: it evaporates water, forms clouds and rain, and feeds rivers, glaciers and groundwater, all of which erode and transport material. It also produces the thermal expansion and contraction that physically weather rocks.Thus, although gravity and tectonic gradients also play a part, the sole/ultimate driving force behind all exogenic geomorphic processes is the sun’s heat, which energises the atmosphere and the climatic processes that wear down the land.
(iii) Are physical and chemical weathering processes independent of each other? If not, why? Explain with examples.
ANSWERNo, physical and chemical weathering processes are not independent; they act together and assist one another. Very rarely does one process operate completely by itself, although one may dominate in a given climate.How they help each other: physical (mechanical) weathering — thermal expansion, pressure release, crystal growth, wetting and drying — breaks large rocks into smaller fragments. This greatly increases the surface area exposed to air and water, which speeds up chemical weathering.Examples: when granite is mechanically fractured along joints by frost or unloading, water and oxygen reach fresh surfaces and chemically alter the feldspar into clay (kaolinisation). Conversely, chemical weathering loosens the bonds and cement between grains so that the weakened rock crumbles and disintegrates mechanically — for instance, carbonation dissolves the cementing material, after which the rock breaks apart easily. So the two operate hand in hand to reduce rocks to a fragmental state.
(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?
ANSWERProcess vs. factors: the process of soil formation (pedogenesis) is the actual sequence of changes by which weathered material becomes soil — weathering produces a mantle, bacteria, mosses and lichens colonise it, dead organisms add humus, plant roots and burrowing animals work the material, and a mature soil profile develops. The soil-forming factors are the controlling conditions that govern how this process operates: parent material, topography, climate, biological activity and time. The factors decide the rate, depth and type of soil that the process produces.Role of climate: climate is an active factor. Precipitation supplies moisture for chemical and biological activity, drives eluviation (downward washing) and illuviation (deposition below), and in wet equatorial areas causes desilication. Temperature raises or lowers chemical and biological activity — high temperatures give deep tropical profiles, while freezing slows activity and leaves mechanically broken material in tundra soils.Role of biological activity: vegetation and organisms add organic matter, humus, moisture retention and nitrogen. Bacterial activity controls humification; humus accumulates in cold climates (slow bacteria) and is low in humid tropics (rapid oxidation). Nitrogen-fixing bacteria like Rhizobium enrich the soil, while earthworms, termites and rodents rework and mix it, improving texture and fertility.
Project Work
Depending upon the topography and materials around you, observe and record climate, possible weathering process and soil contents and characteristics.
HOW TO DO ITThis is a field activity, so your observations will vary with where you live. Choose a small area near your home or school and record it under three heads.1. Climate: note the general climate (hot/humid, dry, cold), the daily temperature range, and whether rainfall is heavy or scanty. For example, “hot semi-arid; large diurnal temperature range; rainfall mostly in monsoon months”.2. Possible weathering process: match the climate to the likely dominant weathering — physical/mechanical weathering (thermal expansion, exfoliation) in dry areas with big temperature swings; chemical weathering (oxidation, hydration, carbonation) in warm humid areas; biological weathering wherever roots, earthworms and burrowing animals are active. Look for flaking rock surfaces, rust-coloured stains (oxidation) or roots prying rocks apart.3. Soil contents and characteristics: describe colour (dark = humus-rich; red = iron oxides; pale = sandy), texture (sandy, loamy, clayey), moisture, and the presence of roots, organic litter or kanker nodules. Present your findings in a neat table and a short paragraph linking the climate to the weathering and the soil you found.
Extra Practice Questions
Short Answer Type Questions
Q1. Distinguish between a geomorphic process and a geomorphic agent.
ANSWERA geomorphic process is a force applied on earth materials that affects and changes them (e.g. weathering, erosion). A geomorphic agent is a mobile medium — running water, glaciers, wind, waves — that actually removes, transports and deposits the materials.
Q2. What is denudation?
ANSWERDenudation is the general term covering all exogenic geomorphic processes — weathering, mass wasting/movements, erosion and transportation — that strip off and wear down the earth’s surface. The word ‘denude’ means to uncover or strip off.
Q3. Differentiate between orogeny and epeirogeny.
ANSWEROrogeny is a mountain-building process in which the crust is severely deformed into folds along long, narrow belts. Epeirogeny is a continent-building process involving simple uplift or warping of large parts of the crust without severe folding.
Q4. Why is weathering said to be an in-situ process?
ANSWERWeathering is called an in-situ or on-site process because it disintegrates and decomposes rocks where they lie, with little or no movement (transportation) of the material. The slight motion that may occur is not the same as transportation.
Q5. What is meant by ‘enrichment’ of ores through weathering?
ANSWERDuring weathering, some materials are removed by chemical or physical leaching through groundwater, so the concentration of the remaining valuable minerals (iron, manganese, aluminium, copper) increases. This rise in concentration, which makes the ore economically viable to exploit, is called enrichment.
Long Answer Type Questions
Q1. Describe the three major groups of weathering processes with examples.
ANSWERWeathering is the mechanical disintegration and chemical decomposition of rocks in situ, and it occurs through three groups of processes that usually act together. (1) Chemical weathering — solution, carbonation, hydration, oxidation and reduction — decomposes or dissolves rock through reactions involving oxygen, water and acids; for example, carbonation dissolves limestone and oxidation rusts iron-bearing minerals. (2) Physical or mechanical weathering depends on applied forces — gravitational overburden, expansion due to temperature changes, crystal growth, and wetting–drying cycles. Thermal expansion and pressure release (unloading) cause rocks to fracture and exfoliate; these processes are small and slow but cause great damage through repeated fatigue. (3) Biological weathering is the contribution or removal of minerals by organisms and physical change due to their growth or movement — burrowing earthworms, termites and rodents expose new surfaces, plant roots prise rocks apart, and decaying matter produces acids that enhance decay. Rarely does one act alone; together they reduce rock to a fragmental state.
Q2. Explain mass movements, the conditions that favour them, and their main types.
ANSWERMass movements transfer rock debris down slopes under the direct influence of gravity, without any geomorphic agent like water, wind or ice carrying it; hence they are not classed as erosion. Material yields only when the disturbing force exceeds the shearing resistance of the slope. Favourable conditions include weak, unconsolidated or thinly bedded rocks, faults and steeply dipping beds, vertical cliffs or steep slopes, abundant precipitation and torrential rain, and scarcity of vegetation. Activating causes include removal of support from below, increase in slope gradient and height, overloading by material or heavy rainfall, earthquakes and explosions, excessive seepage and the indiscriminate removal of vegetation. The three forms of movement are heave, flow and slide. The chief types are creep (very slow), flow (e.g. debris avalanche — rapid and saturated), and rapid slides/falls such as slump (backward-rotational slip), debris slide, debris fall, rockslide (along bedding/joint/fault surfaces) and rockfall (free fall of blocks). Such movements are very common in the tectonically active, steep Himalayas.
Q3. Discuss the five basic factors that control the formation of soils.
ANSWERFive basic factors control soil formation, acting together. (1) Parent material (a passive factor) is the in-situ weathered rock (residual soils) or transported deposits; its texture, structure and mineral composition influence the soil, especially while soils are young. (2) Topography (passive) controls exposure to sunlight and drainage — soils are thin on steep slopes and thick over flat uplands and gentle slopes where erosion is slow and percolation good. (3) Climate (active) is the most important: precipitation supplies moisture and drives eluviation, illuviation and desilication, while temperature controls the rate of chemical and biological activity (deep tropical profiles, shallow tundra soils). (4) Biological activity (active) adds organic matter, humus, moisture retention and nitrogen; bacteria control humification and nitrogen fixation (e.g. Rhizobium), and earthworms, termites and rodents rework the soil. (5) Time (passive) determines maturity — the longer the soil-forming processes operate, the better the profile develops; recently deposited alluvium or glacial till gives young soils with poorly developed horizons.
MCQs & Assertion–Reason
1. The internal forces operating from within the earth are known as:
For each Assertion–Reason question, choose: (A) Both true and the Reason correctly explains the Assertion; (B) Both true but the Reason is not the correct explanation; (C) Assertion true, Reason false; (D) Assertion false, Reason true.
A-R 1. Assertion: The surface of the earth remains uneven.
Reason: Endogenic and exogenic forces act in opposition, so relief variations persist as long as both continue.
A-R 2. Assertion: Weathering is a pre-requisite for mass movement.
Reason: Mass movements occur only over completely weathered, loose materials.
A-R 3. Assertion: Exogenic processes ultimately derive their energy from the sun.
Reason: Solar heating drives the atmosphere and climatic elements such as temperature and precipitation that control weathering and erosion.
A-R 4. Assertion: Deposition is the direct work of a separate geomorphic agent.
Reason: Erosional agents lose velocity and energy on gentler slopes, so the materials they carry settle down on their own.
A-R 5. Assertion: Climate is an active control factor in soil formation.
Reason: Precipitation and temperature regulate the moisture and the rate of chemical and biological activity in the soil.
Answer key: 1-(A), 2-(D), 3-(A), 4-(D), 5-(A).
Exam Tips & Common Mistakes
How to score full marks in this chapter
Always frame your answers around the two opposing groups — endogenic (land-building) versus exogenic (land-wearing). Memorise the four components of denudation (weathering, mass wasting, erosion, transportation) and the three groups of weathering (chemical, physical, biological) with one example each. For diastrophism, be able to contrast orogeny (mountain building, folding) with epeirogeny (continent building, warping). For soils, learn the five factors and clearly tag climate and biological activity as active, and parent material, topography and time as passive. Use the textbook’s own examples — the Himalayas and Nilgiris for landslides, Rhizobium for nitrogen fixation, kanker nodules and hardpans — to show depth.
Common mistakes to avoid
Confusing a geomorphic process (a force) with a geomorphic agent (a mobile medium).
Treating mass movements as erosion — no agent carries the debris; it moves under gravity alone.
Saying weathering involves transportation — it is an in-situ process with little or no motion.
Mixing up orogeny (folding/mountains) with epeirogeny (warping/continents).
Calling weathering a pre-requisite for mass movement or erosion — it only aids them.
Listing all soil factors as ‘active’ — only climate and biological activity are active; the rest are passive.
Frequently Asked Questions
What is Chapter 5 of Class 11 Geography (Fundamentals of Physical Geography) about?
Chapter 5, Geomorphic Processes, explains why the earth’s surface is uneven and how endogenic (land-building) and exogenic (land-wearing) forces shape it. It covers diastrophism and volcanism, the denudational processes of weathering, mass movements, erosion and deposition, and the five factors that control soil formation.
What is the difference between endogenic and exogenic geomorphic processes?
Endogenic processes are powered by energy from within the earth and are mainly land-building forces (diastrophism and volcanism). Exogenic processes are powered ultimately by the sun and gravity and are mainly land-wearing forces — weathering, mass movements, erosion and transportation, grouped together as denudation.
How many questions are there in the NCERT exercise of Class 11 Geography Chapter 5?
The end-of-chapter Exercises have three parts: 3 multiple choice questions, 4 short questions (about 30 words) and 4 long questions (about 150 words), plus a Project Work activity — all answered step by step on this page.
