NDA Lithosphere: rocks, landforms, earthquakes previous year questions with solutions

Answer: (c) III only

Method. Earth's crust: thickness and nature

Source: NCERT Class 11 Fundamentals of Physical Geography, ch. 3. I is wrong: the continental crust is thicker (about 70 km under major mountain systems such as the Himalayas), not thinner. II is wrong: the mean thickness of oceanic crust is about 5 km (continental about 30 km). III is correct: the crust is the brittle outermost solid layer. So III only.

Answer: (b) 1 and 2 only

Method. structure of the Earth

1: correct. Oceanic crust is basaltic and denser (about 3.0 g/⁠cc against 2.7 for continental), so heavier by density. 2: correct. The mantle is by far the largest layer by volume and holds most of the internal heat. 3: wrong. Large convection cells operate in the mantle, not the crust. So 1 and 2 only.

Statement 1 is read as 'denser'; statement 3 puts the cells in the crust, whereas they lie in the mantle.

Answer: (a) Precambrian

Method. geological time scale

The Precambrian is the oldest division of geological time, about 4,600 to 541 million years ago. After it come the Paleozoic, Mesozoic and Cenozoic, in that order.

Answer: (b) Holocene and Pleistocene

Method. geological time scale

The Quaternary period has two epochs: the older Pleistocene and the Holocene (the last 11,700 years). Pliocene and Miocene belong to the Neogene, and Eocene to the Paleogene.

Answer: (d) Lehmann discontinuity

Method. internal discontinuities

From the surface inwards the order is: Conrad (inside the crust), Moho (crust-mantle), Gutenberg (mantle-outer core), and Lehmann (outer core-inner core). Lehmann is the innermost.

Option (c) is printed 'Guttenberg'; the usual spelling is Gutenberg.

Answer: (b) Mohorovicic

Method. Earth discontinuities

The Mohorovicic discontinuity (Moho) lies between the crust and the mantle. The Conrad discontinuity separates upper and lower crust, the Gutenberg discontinuity separates mantle from core, and Repetti is between upper and lower mantle.

Answer: (d) paleogeography

Method. branches of earth science

Paleogeography reconstructs the geography of past geologic periods (ancient maps of land, sea and climate). Paleoclimatology studies ancient climates, paleogeomorphology ancient landforms, and paleolithology ancient rock types.

Answer: (a) 1 only

Method. crust

1: correct. NCERT Class 11 Fundamentals of Physical Geography ch. 3 calls the crust brittle in nature. 2: wrong. The mean thickness of oceanic crust is about 5 km (not 15 km), and that of continental crust about 30 km. So 1 only.

Answer: (c) Crust and upper mantle

Method. definition of lithosphere

The lithosphere is the crust together with the uppermost solid layer of the mantle, about 100 km thick. The upper and lower mantle together, or the core, are not the lithosphere.

Answer: (d) Himalayan Mountains.

Method. lithosphere is thickest under mountains

Crust is thinnest under oceans (about 5 km) and thickest under the major mountain systems, where it can reach about 70 km (NCERT Class 11 Fundamentals of Physical Geography ch. 3). The lithosphere is deepest under the Himalayas, with their deep crustal root, among the options.

Wider literature puts the thickest lithosphere under ancient cratons such as Siberia, but the question follows NCERT mountain crustal thickness.

Answer: (c) crust and uppermost solid mantle.

Method. definition of lithosphere

The lithosphere is the rigid outer shell, made of the crust plus the uppermost solid part of the mantle. The asthenosphere below it is weak and ductile, so the shell is not the full mantle or the core.

Answer: (b) III only

Method. Igneous rocks

Source: NCERT Class 11 Fundamentals of Physical Geography, ch. 5. I is wrong: igneous rocks can be changed into metamorphic rocks (e.g. granite to gneiss). II is wrong: slow cooling at great depth gives large grains; rapid cooling gives very small grains. III is correct: igneous rocks are primary rocks. So III only.

Answer: (c) II and IV

Method. Nature of rocks

Source: NCERT Class 11 Fundamentals of Physical Geography, ch. 5. I is correct: a rock is an aggregate of one or more minerals. II is not correct: soapstone is a talc rock, very soft, while granite is hard. III is correct: gabbro is dark to black and quartzite is often white. IV is not correct: foliation belongs to metamorphic rocks, not sedimentary (which show bedding). The statements not correct are II and IV.

Answer: (a) lithification

Method. Lithification of sediments

Source: NCERT Class 11 Fundamentals of Physical Geography, ch. 5. Loose sediments are compacted and cemented into sedimentary rock by lithification. Weathering breaks rock down, mass wasting moves debris downslope, solifluction is slow soil flow in cold regions.

Answer: (c) Sandstone

Method. Metamorphic rocks and their parent rocks

Source: NCERT Class 11 Fundamentals of Physical Geography, ch. 5. Sandstone metamorphoses into quartzite; limestone gives marble, shale gives slate, and pegmatite is an igneous rock.

Answer: (b) 1 and 2 only

Method. NCERT mineral table: feldspar

Source: NCERT Class 11 Fundamentals of Physical Geography, ch. 5 (Minerals and Rocks), table of major minerals. Statement 1 is correct: about half of the earth's crust is feldspar. Statement 2 is correct: feldspar is light cream to salmon pink. Statement 3 is wrong: silicon and oxygen are the elements common to all feldspars; sodium, potassium, calcium and aluminium appear in particular varieties, magnesium is not the common element. So 1 and 2 only.

Answer: (d) 1, 2 and 3

Method. Sedimentary rocks classified by mode of formation

Source: NCERT Class 11 Fundamentals of Physical Geography, ch. 5. Mechanically formed: sandstone, conglomerate, shale, loess. Chemically formed: chert, limestone, halite, potash. Organically formed: geyserite, chalk, limestone, coal. All three pairs match the NCERT lists (the wider literature treats geyserite as a silica deposit from hot springs, but the NCERT wording is 'organically formed').

Answer: (c) 2, 1, 3

Method. NCERT mineral shares of the crust

NCERT Class 11 Fundamentals of Physical Geography ch. 5 table: mica about 4%, amphibole about 7%, pyroxene about 10%. Ascending order: mica (2), amphibole (1), pyroxene (3), giving 2, 1, 3.

Item 1 is printed 'Amphibolite', which is a rock; it is read as the mineral group amphibole.

Answer: (d) Tuff

Method. volcanic ash rock

Volcanic ash that is consolidated is tuff. When running water carries the ash and lays it as a layer, it forms a sedimentary tuff. Basalt is lava rock, lapilli are small ejected fragments and slate is metamorphic.

Answer: (d) Granite

Method. rocks in NCERT lists

NCERT Class 11 Fundamentals of Physical Geography ch. 5 lists granite, gabbro and basalt among igneous rocks, and 'gneissoid, granite, syenite, slate, schist, marble, quartzite' among metamorphic rocks. Only granite is in both lists. Gabbro is igneous only, geyserite is sedimentary (organic), and gneissoid is metamorphic only.

Answer follows the NCERT lists, in which granite is named under both heads; in strict petrology granite is igneous and its metamorphic form is gneiss.

Answer: (a) Pyroxene is commonly found in meteorites

Method. NCERT mineral table

NCERT Class 11 Fundamentals of Physical Geography ch. 5: pyroxene is commonly found in meteorites. Amphiboles form about 7% of the crust (not 20%). Quartz is insoluble in water. 'Sedimentary' comes from the Latin sedimentum (settling), not 'kelimentum'.

Answer: (b) Slate

Method. igneous versus metamorphic

Granite, basalt and gabbro are igneous. Slate is a metamorphic rock, made from shale by low-grade metamorphism.

Answer: (b) Batholith

Method. intrusive igneous bodies

The batholith is the largest intrusive body, a deep-seated granite mass whose base is not exposed. Laccolith, lopolith and phacolith are smaller bodies at shallower levels. So batholith is the lowermost intrusive form.

'Lowermost/⁠innermost' is vague; the deepest-seated of the four is the batholith.

Answer: (d) Rocks that originally were composed of one dominant mineral are often foliated by metamorphism.

Method. foliation in metamorphic rocks

Foliation forms by segregation of minerals into wavy bands or platy layers, and broad bands (gneiss) give very hard rock while thin layers (slate, schist) flake apart, so a, b and c are right. Rocks that originally were one dominant mineral, such as quartz in sandstone or calcite in limestone, tend to become non-foliated rocks (quartzite, marble). Statement d says the opposite, so it is not correct.

The statement wording follows a standard physical-geography text rather than NCERT; the logic of non-foliated quartzite and marble from single-mineral rocks decides it.

Answer: (c) Both 1 and 2

Method. rock cycle

1: correct. Rocks keep changing form in the rock cycle (NCERT Class 11 Fundamentals of Physical Geography ch. 5). 2: correct. The transformation is by weathering, erosion and metamorphism, with melting as well. Both are correct.

Answer: (a) Batholiths.

Method. intrusive igneous bodies

Batholiths are the largest intrusive bodies, domed masses of granite cooled deep in the crust. A laccolith is a smaller lens or mushroom dome, a lopolith is saucer-shaped and a phacolith is a lens in a fold. 'Large domes in the deeper crust' means batholith.

Answer: (d) Chalk

Method. origin of sedimentary rocks

NCERT Class 11 Fundamentals of Physical Geography ch. 5 classes sedimentary rocks as mechanically formed (sandstone, shale, loess), chemically formed (chert, halite, potash) and organically formed (geyserite, chalk, limestone, coal). Chalk is the organically formed one.

Shortcut. Shale is mechanical, halite and chert chemical; only chalk is organic.

Answer: (c) Decomposition

Method. agents of metamorphism: heat, pressure, chemically active fluids

Metamorphism is change in a rock by heat, pressure (compression) and chemically active fluids/⁠solutions (NCERT Class 11 Fundamentals of Physical Geography ch. 5). Heat, compression and solution all fit. Decomposition is the breakdown of rock in weathering, not an agent of metamorphism.

Answer: (c) Dolomite

Method. igneous versus sedimentary rock

Gabbro (intrusive), granite (intrusive) and basalt (extrusive) are igneous rocks, formed by cooling of magma or lava. Dolomite is a carbonate rock (calcium-magnesium carbonate) laid down as a chemical/⁠biochemical sediment, so it is sedimentary. Source: NCERT Class 11 Fundamentals of Physical Geography ch. 5.

Answer: (d) Shield volcanoes

Method. Volcano types and examples

Source: NCERT Class 11 Fundamentals of Physical Geography, ch. 3. Shield volcanoes are the largest, built of basaltic fluid lava with gentle slopes; the Hawaiian volcanoes are the most famous examples.

Answer: (d) I, II and III

Method. Composite volcanoes

Source: NCERT Class 11 Fundamentals of Physical Geography, ch. 3. Composite volcanoes erupt cooler, more viscous lava and often erupt explosively; large quantities of pyroclastic material and ash are thrown out and accumulate around the vent in layers, giving the composite structure. All three statements are correct.

Answer: (b) composite volcano

Method. Types of volcanoes

Mount Ibu (Halmahera, Indonesia) is a stratovolcano, i.e. a composite volcano built of alternating layers of lava and pyroclastic material. It is not a shield volcano (gentle basaltic slopes), a dome or a small cinder cone.

Answer as at the sitting (2026): composite volcano.

Answer: (c) Both 1 and 2

Method. Oceanic trenches and plate tectonics

Source: NCERT Class 11 Fundamentals of Physical Geography, ch. 4 (Distribution of Oceans and Continents, ocean floor). Trenches are the deepest parts of the oceans and are of great significance in the study of plate movements (subduction zones); they are associated with active volcanoes and strong earthquakes. Both statements are correct.

Answer: (c) Hawaiian Islands

Method. Volcanic island chains: ridge versus hotspot

Azores, Ascension and Tristan da Cunha are volcanic islands on or beside the Mid-Atlantic Ridge. The Hawaiian Islands lie in the middle of the Pacific Plate, far from any mid-oceanic ridge, and form a hotspot chain over a mantle plume. So Hawaiian Islands is the one not associated with a ridge.

Answer: (a) Mt. Fuji

Method. fold mountains

The Alps, Andes and Rockies are young fold mountains formed by compression at plate convergence. Mt. Fuji is a volcanic cone (stratovolcano), not a fold mountain.

Answer: (d) Antarctic Plate

Method. major and minor plates

Cocos, Nazca and Caroline are minor plates in NCERT Class 11 Fundamentals of Physical Geography ch. 4. The Antarctic Plate, with the surrounding oceanic plate, is one of the seven major plates. So Antarctic is the one that is not minor.

Answer: (d) 1, 2 and 3

Method. Iceland on the Mid-Atlantic Ridge

Iceland lies on the divergent boundary of the Mid-Atlantic Ridge. Volcanic and geothermal activity gives geothermal energy (about a quarter of the electricity supply, plus heating). Lava adds new land, as at the island of Surtsey. Geysers and volcanoes draw tourists. All three are advantages.

Answer: (c) Recumbent

Method. fold types by axial plane

In a recumbent fold the axial plane is nearly horizontal, because the limbs are overturned and lie almost flat. An isoclinal fold has parallel limbs. A monocline is a single step-like bend, and an anticline is an upfold with an upright or inclined axial plane.

Answer: (a) Pacific Plate

Method. major and minor plates

NCERT Class 11 Fundamentals of Physical Geography ch. 4: the seven major plates are Antarctic, North American, South American, Pacific, India-Australia-New Zealand, African and Eurasian. Cocos, Arabian, Philippine (with Nazca, Caroline, Fuji, Juan de Fuca) are minor. The Pacific Plate is the major one.

Answer: (d) 1, 2 and 3

Method. Circum-Pacific Ring of Fire

The Ring of Fire rings the Pacific. It lies along convergent plate boundaries (subduction zones), holds most of the world's active volcanoes and earthquakes, and is bordered by deep oceanic trenches (Mariana, Peru-Chile, Japan). All three statements are correct.

Answer: (c) I and III only

Method. P and S waves, shadow zone

Source: NCERT Class 11 Fundamentals of Physical Geography, ch. 3. I is correct: P waves are longitudinal like sound waves. II is wrong: S waves travel only through solids, not liquids or gases. III is correct per NCERT: the zone 105 to 145 degrees from the epicentre is the shadow zone for both. So I and III only.

Answer: (c) Both I and II

Method. Earthquake waves: body and surface waves

Source: NCERT Class 11 Fundamentals of Physical Geography, ch. 3. Earthquake waves are of two types, body waves (P and S, travelling through the interior) and surface waves. Body waves interact with the surface rocks and generate surface waves. Both statements are correct.

Answer: (c) Both I and II

Method. P and S waves: arrival and motion

Source: NCERT Class 11 Fundamentals of Physical Geography, ch. 3. P waves are the fastest and reach the seismograph first. P waves are longitudinal: particles move to and fro along the direction of travel; S waves are transverse: particles move at right angles to it, up and down. Both correct.

Answer: (c) Both I and II

Method. Focus (hypocentre) of an earthquake

Source: NCERT Class 11 Fundamentals of Physical Geography, ch. 3. The focus, also called the hypocentre, is the point below the surface where energy is released and the rupture starts, and it can lie many kilometres deep. Both statements are correct.

Answer: (a) 1 only

Method. Shadow zones of P and S waves

Source: NCERT Class 11 Fundamentals of Physical Geography, ch. 3 (Interior of the Earth). Statement 1 follows the NCERT text: the zone between 105 and 145 degrees from the epicentre is identified as the shadow zone for both types of waves (S waves are in addition absent beyond 105 degrees). Statement 2 is wrong: the S-wave shadow zone is much larger than the P-wave one, covering a little over 40 per cent of the earth's surface, because S waves cannot pass through the liquid outer core. So 1 only.

Answer: (c) Both 1 and 2

Method. surface (L) waves

L waves are long-period surface waves. They travel only along the surface and follow the Earth's circumference, and their speed is nearly constant, unlike body waves that vary with depth. Both statements are accepted.

Statement 2 depends on the reference's wording; the speed of surface waves is only roughly constant.

Answer: (b) 1 and 2 only

Method. earthquake terms

1: correct. The epicentre is the surface point directly above the focus. 2: correct. P and S waves are body waves radiating from the focus. 3: wrong. Shallow-focus earthquakes do more damage, since the waves reach the surface with more energy. So 1 and 2 only.

Answer: (b) 2 and 3

Method. earthquake waves

1: wrong. The point on the surface nearest to the focus is the epicentre, whereas the hypocentre is the focus. 2: correct. The denser the material, the higher the wave velocity (NCERT Class 11 Fundamentals of Physical Geography ch. 3). 3: correct. P waves are fastest and arrive first. So 2 and 3.

Answer: (d) P waves have maximum area covered under its shadow zone.

Method. seismic waves and shadow zones

P waves are faster, arrive first and pass through solids, liquids and gases, so a and b are right. P waves reappear beyond 145 degrees, so c is right. The P shadow zone is the band 105 to 145 degrees, while the S shadow zone spans everything beyond 105 degrees, so the S waves have the larger shadow zone. d is incorrect. Source: NCERT Class 11 Fundamentals of Physical Geography ch. 3.

Answer: (b) Focus.

Method. focus and epicentre

The focus (hypocentre) is the point inside the Earth where the rupture starts and the waves originate. The epicentre is the point on the surface directly above it. Source: NCERT Class 11 Fundamentals of Physical Geography ch. 3.

Answer: (b) 1 and 2 only

Method. Richter magnitude scale

1: correct. Charles F. Richter devised the scale in 1935. 2: correct. Magnitude relates to the energy released at the focus (each unit about 32 times more energy). 3: wrong in the NCERT account. NCERT Class 11 Fundamentals of Physical Geography ch. 3 gives the magnitude scale as 0 to 10. So statements 1 and 2 only.

Statement 3 is arguable in wider literature, since the Richter scale is open-ended in principle; the key follows NCERT (0 to 10).

Answer: (a) Water pressure

Method. Physical versus chemical weathering

Source: NCERT Class 11 Fundamentals of Physical Geography, ch. 6. Oxidation, carbonation and hydration are chemical weathering processes (with solution and reduction). Water pressure is a physical (mechanical) process: NCERT lists 'water pressures controlled by wetting and drying cycles' among the applied forces of physical weathering, with gravitational and expansion forces. So water pressure.

Answer: (d) All the four

Method. Chemical weathering processes

Source: NCERT Class 11 Fundamentals of Physical Geography, ch. 6 (Geomorphic Processes). Solution removes soluble minerals, i.e. leaching. Carbonation, the reaction of carbonates and bicarbonates with minerals, helps break down feldspars and carbonate rocks. Hydration (addition of water) swells minerals and increases volume, leading to fracturing. Oxidation (iron, manganese) changes colour, e.g. to reddish brown or yellow. All four are correctly matched.

Answer: (d) 1, 2 and 3

Method. applied forces in physical weathering

NCERT Class 11 Fundamentals of Physical Geography ch. 6: physical weathering depends on applied forces. They are gravitational forces (overburden pressure, load, shearing stress), expansion forces (temperature changes, crystal growth, animal activity) and water pressures (wetting and drying cycles). All three are listed.

Answer: (d) Thawing

Method. chemical weathering processes

Chemical weathering comprises solution, carbonation, hydration, oxidation and reduction. Thawing is the melting of ice and belongs with freeze-thaw (frost) action, which is physical. So thawing is not chemical.

Answer: (a) Granite

Method. tors

Tors are rounded residual blocks left on hills of massive jointed rock, formed when weathering along joints removes the surrounding rock. This is typical of granite (and similar crystalline rocks). Limestone gives karst, and alluvial material is loose.

Answer: (a) 1 only

Method. mass wasting versus erosion

A boulder moved downhill under gravity is mass wasting (mass movement). The loosening by heavy rain is itself part of the mass movement: NCERT Class 11 Fundamentals of Physical Geography ch. 6 lists 'overloading due to heavy rainfall, saturation and lubrication of slope materials' among its activating causes. The same chapter says mass movements are not erosion, since no geomorphic agent such as water, wind or ice carries the debris. Weathering is in-situ disintegration and decomposition over time and does not move the rock. So 1 only.

A reader who counts the rain as weathering would reach d; the NCERT reading gives a.

Answer: (c) 2 and 3 only

Method. landslides

1: wrong. Landslides occur mainly on steep slopes, not only gentle ones. 2: correct. Clay-rich soil becomes slippery when wet and fails. 3: correct. Earthquakes are a common trigger. So 2 and 3 only.

Shortcut. Statement 1 is false; the only option without 1 is c.

Answer: (b) Avalanche

Method. avalanche

An avalanche is a mass of snow and ice rushing down a steep slope, mixing falling, rolling, sliding and flowing, and it endangers skiers and mountaineers. Slump and earthflow, landslide and rockslide are movements of soil and rock.

Answer: (a) Mechanical

Method. weathering in hot deserts

Hot deserts have large day-night temperature ranges and little moisture. Rock expands and contracts, and cracks and breaks, so mechanical (physical) weathering dominates, and chemical and biological weathering are weak without water. Leaching is a soil process.

Answer: (a) Denudation

Method. denudation

Denudation is the wearing down of the land surface, and it includes weathering, mass wasting, erosion and transportation. Endogenetic processes are internal, diastrophism is crustal deformation and mountain building belongs to the endogenetic group.

Answer: (a) Hydration.

Method. hydration

Hydration is the chemical addition of water to minerals, which then expand, as when anhydrite becomes gypsum. Oxidation adds oxygen, hydrolysis is a reaction with the H+ and OH- of water that changes the mineral, and carbonation is a reaction with carbonic acid. Source: NCERT Class 11 Fundamentals of Physical Geography ch. 6.

Answer: (b) Physical weathering

Method. salt weathering

Crystallisation of salts in rock pores and cracks widens them by pressure. It is a mechanical process, with no change in the minerals, so it is physical weathering. NCERT Class 11 Fundamentals of Physical Geography ch. 6 lists it as 'salt weathering' under physical weathering.

Answer: (d) Exfoliation

Method. physical versus chemical weathering

Chemical weathering comprises solution, carbonation, hydration, oxidation and reduction. Exfoliation is the peeling of rock sheets through temperature change and unloading, so it is physical (mechanical) weathering. Source: NCERT Class 11 Fundamentals of Physical Geography ch. 6.

Answer: (b) hot and humid climate

Method. climate and chemical weathering

Chemical weathering needs water and warmth, because reactions speed up with temperature and moisture. It is strongest in hot, humid regions, such as the equatorial rainforests. Cold or dry climates favour physical weathering. Source: NCERT Class 11 Fundamentals of Physical Geography ch. 6.

Answer: (d) I, II, III and IV

Method. Types of river erosion

River erosion works by abrasion (corrasion), attrition, hydraulic action and solution (corrosion). All four are main types.

Answer: (b) Arid landforms

Method. arid landforms

A bolson is a basin in a desert. Its lowest part holds a playa, a temporary lake that dries to a salt-and-clay flat. Playa is a desert (arid) landform. NCERT Class 11 Fundamentals of Physical Geography ch. 7 treats it under arid landforms.

Answer: (a) 1 only

Method. barchan dune

1: correct. A barchan is a crescent-shaped sand dune built by wind from a steady direction. 2: wrong. The windward side is gentle and convex, and the steep concave slope is on the leeward (slip) face. 3: wrong. The horns point downwind, in the direction the wind blows. So 1 only.

Answer: (d) Ladakh

Method. glacial landforms in India

Moraines, eskers and outwash plains are glacial landforms, found where glaciers are or have been. Of the union territories, Ladakh is the glaciated one (Siachen, Karakoram, Zanskar). Andaman and Nicobar, Lakshadweep and Puducherry are tropical coastal or island areas.

Answer: (a) Playa

Method. desert landforms

A playa is the flat, fine-grained floor of a temporary (ephemeral) desert lake. An oasis is a fertile spot with water, a drumlin is a glacial deposit and a natural levee is a river deposit.

Answer: (b) Oxbow lake

Method. fluvial erosion plus deposition

A pothole and a rapid are erosional. A levee is purely depositional. An oxbow lake needs both: the river erodes the outer bank and deposits on the inner bank of a meander until the neck is cut through, and deposition then seals off the loop. Source: NCERT Class 11 Fundamentals of Physical Geography ch. 7.

Answer: (a) Drumlins.

Method. glacial depositional landforms

Drumlins are smooth oval hills of till, elongated along the ice flow. Many in a group look like a basket of eggs on the ground, which gives 'basket-of-eggs topography'. Eskers are sinuous ridges, cirques are rock hollows, and moraines are ridges of till.

Answer: (d) underground water.

Method. landforms of groundwater

Stalactites hang from cave roofs, stalagmites rise from the floor, and where the two meet they form pillars. All are deposits of calcium carbonate from dripping water in limestone caves. This is the work of underground water. Source: NCERT Class 11 Fundamentals of Physical Geography ch. 7.

Answer: (d) Canyon.

Method. gorge versus canyon

NCERT Class 11 Fundamentals of Physical Geography ch. 7: a gorge is a deep valley with very steep, straight sides. A canyon is characterised by steep step-like side slopes (hard and soft strata alternating) and may be as deep as a gorge. Step-like slopes mean a canyon.

Answer: (c) Stack

Method. coastal erosional versus depositional landforms

Tombolo (bar joining an island to the mainland), sand bar and spit are built by wave and current deposition. A stack is an isolated rock left when a sea arch collapses, so it is erosional.

Answer: (a) 1, 2 and 3

Method. coastal erosional landforms

Wave action cuts a notch at the cliff base, which makes the cliff retreat and a sea arch form. Notch, sea arch and cliff are erosional. A hook is a recurved spit, built by deposition, so statement 4 is wrong.

Answer: (c) Both 1 and 2

Method. Soil forming processes: four classes

Soil formation is described as four classes of process: enrichment (addition of material), removal (loss), translocation (movement within the profile) and transformation (change of materials in place). Statement 1 lists them. Statement 2 defines translocation correctly: fine particles are removed from upper horizons by eluviation and deposited in lower horizons by illuviation. Both correct.

Reading taken: 'enrichment' is the usual 'additions' class; if the setter regarded the label as wrong the answer would be b, but the sense of statement 1 matches the standard four-class scheme.

Answer: (b) Histosols

Method. soil orders

Histosols are organic soils, made of thick accumulated plant remains (peat, bog soils). Aridisols are dry-region soils, Oxisols are weathered tropical soils and Vertisols are cracking clays.

Answer: (c) Taiga forest

Method. soil-forming regimes

Podsolization is the leaching and acidic soil-forming process of cool, humid, coniferous forests. The taiga (boreal forest) is the typical region.

Answer: (a) Calcification

Method. soil-forming regimes

Calcification occurs where evapotranspiration exceeds precipitation, as in arid and semi-arid regions. Water rises by capillary action and leaves calcium carbonate near the surface. Laterization is in hot, wet climates, podsolization in cool, humid ones, and gleization under waterlogging.

Answer: (d) Human habitation

Method. soil-forming factors

The soil-forming (pedogenic) factors are parent material, topography (relief), climate, biological activity and time. Human habitation is not one of these. Source: NCERT Class 11 Fundamentals of Physical Geography ch. 6 (soils).