I85PREP
⌘ K
Assam ASSEB HSLC Elective Geography study materials
Assam ASSEB HSLC Elective Geography study resources

Assam ASSEB HSLC Elective Geography practice questions

One question at a time. Build your Assam ASSEB HSLC Elective Geography understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Physical Geography: Earth's Interior, Rocks, and Landforms

Which layer of the Earth's interior is composed mainly of iron and nickel and behaves as a liquid?

  1. The outer core Correct answer.
  2. The inner core
  3. The asthenosphere
  4. The lower mantle

Explanation

The outer core lies between the mantle and the inner core and consists largely of molten iron and nickel. Because it is liquid, it cannot transmit S-waves, which is how seismologists detect it. The inner core is solid despite its higher temperature because of enormous pressure.

Question 2Physical Geography: Earth's Interior, Rocks, and Landforms

The discontinuity that separates the Earth's crust from the mantle is known as the

  1. Lehmann discontinuity
  2. Mohorovicic discontinuity Correct answer.
  3. Repetti discontinuity
  4. Gutenberg discontinuity

Explanation

The Mohorovicic discontinuity, or Moho, marks the boundary where seismic P-wave velocities jump sharply from crustal to mantle values. It lies at roughly 5-10 km beneath the oceans and 30-70 km beneath continents. The other named discontinuities occur at deeper boundaries.

Question 3Physical Geography: Earth's Interior, Rocks, and Landforms

S-waves from an earthquake cannot travel through the outer core. What does this observation most directly indicate about that layer?

  1. It contains no iron
  2. It is hotter than the inner core
  3. It is denser than the mantle
  4. It behaves as a liquid Correct answer.

Explanation

S-waves are transverse and propagate only through material with shear strength, that is, through solids. Their disappearance beyond about 103 degrees from the epicentre shows that the outer core lacks shear strength and is liquid. Density and temperature differences alone would not block S-waves.

Question 4Physical Geography: Earth's Interior, Rocks, and Landforms

Which type of rock forms when molten magma cools and solidifies beneath the Earth's surface?

  1. Regionally metamorphosed rock
  2. Extrusive igneous rock
  3. Clastic sedimentary rock
  4. Intrusive igneous rock Correct answer.

Explanation

Intrusive, or plutonic, igneous rocks crystallise from magma that solidifies at depth, giving them coarse grains because cooling is slow. Extrusive rocks form at the surface from lava and are typically fine-grained. Sedimentary and metamorphic rocks form by entirely different processes.

Question 5Physical Geography: Earth's Interior, Rocks, and Landforms

Granite is a coarse-grained igneous rock. The most likely reason for its coarse texture is that

  1. it cooled very rapidly at the surface
  2. it was deposited in layers by flowing water
  3. it was subjected to intense directed pressure after formation
  4. it cooled slowly at depth, allowing large crystals to grow Correct answer.

Explanation

Crystal size in igneous rocks depends mainly on cooling rate. Slow cooling at depth gives crystals time to grow large, producing a coarse, phaneritic texture as in granite. Rapid surface cooling produces fine-grained or glassy rocks instead.

Question 6Physical Geography: Earth's Interior, Rocks, and Landforms

Which of the following is a sedimentary rock formed mainly from the chemical precipitation of calcium carbonate?

  1. Shale
  2. Quartzite
  3. Gabbro
  4. Limestone Correct answer.

Explanation

Limestone commonly forms when calcium carbonate precipitates from solution or accumulates as shell debris. It is a sedimentary rock of chemical or organic origin. Shale is clastic, while quartzite and gabbro are metamorphic and igneous respectively.

Question 7Physical Geography: Earth's Interior, Rocks, and Landforms

Marble is formed from limestone through the process of

  1. compaction and cementation
  2. melting and recrystallisation
  3. weathering and erosion
  4. metamorphism under heat and pressure Correct answer.

Explanation

Marble is a metamorphic rock produced when limestone is subjected to heat and pressure, which recrystallises the calcite without melting it. Compaction and cementation produce sedimentary rocks, and melting would produce magma rather than marble.

Question 8Physical Geography: Earth's Interior, Rocks, and Landforms

In the rock cycle, which process converts igneous rock directly into sediment?

  1. Solidification of magma
  2. Weathering and erosion Correct answer.
  3. Partial melting
  4. Metamorphism

Explanation

Weathering breaks exposed rock into fragments and dissolved material, and erosion transports the debris, which may later lithify into sedimentary rock. Metamorphism and melting act on rock without producing sediment, and solidification works in the opposite direction.

Question 9Physical Geography: Earth's Interior, Rocks, and Landforms

The theory of plate tectonics holds that the lithospheric plates move because

  1. convection currents in the mantle provide the driving force Correct answer.
  2. the Earth's rotation drags the crust around the core
  3. the continents drift freely through the oceanic crust
  4. tidal forces pull the plates apart each day

Explanation

Slow convection in the mantle, together with slab pull and ridge push, provides the energy that moves rigid lithospheric plates over the weaker asthenosphere. The older idea of continents ploughing independently through oceanic crust has been rejected. Rotation and tides are far too weak to drive plates.

Question 10Physical Geography: Earth's Interior, Rocks, and Landforms

A deep ocean trench with a chain of volcanic islands nearby is most likely to occur at

  1. a divergent boundary in the mid-ocean
  2. a hot spot far from any plate margin
  3. a convergent boundary where an oceanic plate subducts Correct answer.
  4. a transform fault on a continent

Explanation

Where an oceanic plate descends beneath another plate, the down-bending slab creates a trench, and rising magma generates an island arc. This pairing of trench and volcanic arc is characteristic of subduction zones. Divergent and transform boundaries lack subduction, and hot spots lack trenches.

Question 11Physical Geography: Earth's Interior, Rocks, and Landforms

Fold mountains such as the Himalayas are formed primarily by

  1. erosion of a plateau by glacial ice
  2. vertical uplift above a mantle hot spot
  3. tension and rifting along a divergent margin
  4. compression of sediments along a convergent plate margin Correct answer.

Explanation

When two continental plates collide, the sedimentary sequences between them are compressed, crumpled into folds and uplifted, building fold mountains. Tension produces faults and rifts rather than folds, and hot spots or erosion do not generate folded ranges.

Question 12Physical Geography: Earth's Interior, Rocks, and Landforms

A block mountain, or horst, is produced when

  1. layers are compressed into a broad upfold
  2. a block of crust is uplifted between two parallel normal faults Correct answer.
  3. magma pushes up the crust into a dome
  4. a river cuts down into a plateau

Explanation

Crustal tension causes blocks to drop along normal faults, leaving the intervening block standing high as a horst, with rift valleys on either side. An upfold produced by compression is an anticline, which is different in origin and form.

Question 13Physical Geography: Earth's Interior, Rocks, and Landforms

The instrument used to record the vibrations produced by an earthquake is called a

  1. Altimeter
  2. Seismograph Correct answer.
  3. Hygrograph
  4. Barograph

Explanation

A seismograph detects ground motion and produces a seismogram from which the earthquake's location and magnitude are determined. Barographs and hygrographs record atmospheric pressure and humidity, and altimeters measure height.

Question 14Physical Geography: Earth's Interior, Rocks, and Landforms

The point on the Earth's surface directly above the focus of an earthquake is called the

  1. hypocentre
  2. seismic shadow
  3. epicentre Correct answer.
  4. isoseismal line

Explanation

The focus, or hypocentre, is the actual point of rupture within the Earth, and the epicentre is the point vertically above it on the surface. Seismic shaking is generally strongest near the epicentre. Isoseismal lines join places of equal shaking intensity.

Question 15Physical Geography: Earth's Interior, Rocks, and Landforms

Which of the following best explains why the damage caused by an earthquake of the same magnitude can differ greatly between two towns?

  1. Local geology, building quality and distance from the epicentre vary Correct answer.
  2. The Richter scale changes with latitude
  3. Magnitude is measured differently in each town
  4. Earthquakes always release more energy in towns than in villages

Explanation

Magnitude describes the energy released at the source, but the resulting intensity depends on distance from the focus, the nature of the ground, and the strength of buildings. Soft alluvium, for example, amplifies shaking compared with firm bedrock. Magnitude itself does not vary with location.

Question 16Physical Geography: Earth's Interior, Rocks, and Landforms

A volcano that erupts very fluid basaltic lava quietly, building broad gently sloping sides, is called a

  1. Cinder cone
  2. Composite cone
  3. Shield volcano Correct answer.
  4. Caldera

Explanation

Low-viscosity basaltic lava flows far before solidifying, producing the wide, gently sloping profile of a shield volcano such as Mauna Loa. Composite cones form from alternating viscous lava and ash, while cinder cones are built of ejected fragments.

Question 17Physical Geography: Earth's Interior, Rocks, and Landforms

The Deccan Traps of peninsular India are an example of

  1. metamorphosed limestone
  2. deep-sea trench sediments
  3. fissure eruptions that spread vast sheets of basaltic lava Correct answer.
  4. wind-deposited sand dunes

Explanation

The Deccan Traps consist of thick, extensive sheets of basaltic lava erupted from fissures and built up in successive flows. Their step-like weathering profile gives them their name. They are igneous, not sedimentary or metamorphic, in origin.

Question 18Physical Geography: Earth's Interior, Rocks, and Landforms

Which of the following landforms is produced mainly by the erosional work of a river in its upper course?

  1. Alluvial fan
  2. V-shaped valley Correct answer.
  3. Delta
  4. Oxbow lake

Explanation

In the upper course the river has a steep gradient and strong vertical erosion, cutting a narrow V-shaped valley. Alluvial fans, oxbow lakes and deltas are depositional features found lower down the course.

Question 19Physical Geography: Earth's Interior, Rocks, and Landforms

A waterfall typically develops where a river crosses

  1. a wide floodplain of alluvium
  2. a band of hard rock lying downstream of softer rock Correct answer.
  3. a point where the river reaches its base level
  4. the middle course of a meandering channel

Explanation

Differential erosion explains waterfalls: softer rock downstream is worn away faster, leaving a step of resistant rock over which the water plunges. The plunge pool then undermines the hard cap, so the fall retreats upstream over time. Floodplains and meanders are low-gradient depositional settings.

Question 20Physical Geography: Earth's Interior, Rocks, and Landforms

A meander in a river is best described as

  1. a fan of sediment at the foot of a mountain
  2. a steep gorge produced by uplift
  3. a broad bend formed by lateral erosion on the outer bank and deposition on the inner bank Correct answer.
  4. a straight channel cut into bedrock

Explanation

Meanders arise because faster flow erodes the outer bank while slower flow deposits sediment on the inner bank, so the bend migrates and becomes more pronounced. Over time cut-offs can leave oxbow lakes. Straight bedrock channels and gorges have a different origin.

Question 21Physical Geography: Earth's Interior, Rocks, and Landforms

A river deposits its load to form a delta when it

  1. freezes solid during winter
  2. flows over a steep rocky gradient
  3. enters a standing body of water and loses velocity Correct answer.
  4. cuts down rapidly into a plateau

Explanation

When a river reaches a sea or lake, its velocity falls sharply and its sediment settles, building a delta if the supply exceeds the removal by waves and tides. Steep gradients and rapid incision favour erosion, not deposition.

Question 22Physical Geography: Earth's Interior, Rocks, and Landforms

Which process is chiefly responsible for the formation of a U-shaped valley?

  1. Deposition of sediment by a meandering river
  2. Glacial erosion by an ice tongue moving down a pre-existing valley Correct answer.
  3. Wind abrasion along a desert floor
  4. Chemical solution of limestone by groundwater

Explanation

A glacier grinding down a valley widens and deepens it, straightening the sides and producing the characteristic U-shaped cross-section, often with truncated spurs and hanging valleys. Rivers cut V-shaped valleys, and wind and groundwater produce quite different forms.

Question 23Physical Geography: Earth's Interior, Rocks, and Landforms

A moraine is best defined as

  1. an accumulation of unsorted rock debris carried and deposited by a glacier Correct answer.
  2. a lake formed in a volcanic crater
  3. a ridge of sand deposited by wind
  4. a smooth bedrock surface polished by ice

Explanation

Glaciers transport material of many sizes, and when the ice melts this unsorted debris is left as a moraine, whether terminal, lateral or ground. Wind deposits are well sorted, and polished bedrock is an erosional rather than depositional feature.

Question 24Physical Geography: Earth's Interior, Rocks, and Landforms

In a region of horizontally bedded limestone, which combination of processes most typically produces caves, sinkholes and underground drainage?

  1. Wind deflation of loose sand
  2. Glacial plucking and abrasion
  3. Chemical solution of calcium carbonate by slightly acidic water Correct answer.
  4. Frost shattering of jointed rock

Explanation

Rainwater charged with dissolved carbon dioxide forms weak carbonic acid, which dissolves calcium carbonate along joints and bedding planes, enlarging them into caves and sinkholes and creating karst drainage. The other processes act mechanically and cannot dissolve limestone.

Question 25Physical Geography: Earth's Interior, Rocks, and Landforms

The boundary between the crust and the mantle is deeper beneath a young fold mountain range than beneath an ocean basin mainly because

  1. the crust beneath mountains is thicker and buoyant, so it floats higher on the mantle Correct answer.
  2. seismic waves travel faster through mountain rock
  3. ocean basins are underlain by continental crust
  4. the mantle beneath mountains is made of liquid iron

Explanation

Continental crust is less dense than the mantle and behaves in a buoyant, isostatic manner, so a thick crustal root supports high mountains and pushes the Moho to greater depth. Ocean basins, underlain by thinner and denser basaltic crust, stand lower and have a shallower Moho.

Question 26Physical Geography: Earth's Interior, Rocks, and Landforms

Which layer of the Earth's interior lies directly beneath the crust and consists largely of solid silicate rock rich in iron and magnesium?

  1. The inner core
  2. The atmosphere
  3. The outer core
  4. The mantle Correct answer.

Explanation

The Earth is layered by composition and physical state. The mantle lies immediately below the crust and is made of dense iron- and magnesium-rich silicate rock, most of which behaves as a solid over short timescales. The core lies deeper still and is dominated by iron and nickel.

Question 27Physical Geography: Earth's Interior, Rocks, and Landforms

The Mohorovičić discontinuity, usually called the Moho, marks the boundary between which two zones?

  1. The crust and the mantle Correct answer.
  2. The outer core and the inner core
  3. The lithosphere and the asthenosphere
  4. The mantle and the outer core

Explanation

Seismic waves change speed abruptly at the Moho, showing a change in rock density and composition. This discontinuity separates the crust above from the mantle below and is shallower under oceans than under continents.

Question 28Physical Geography: Earth's Interior, Rocks, and Landforms

Which of the following best describes an igneous rock?

  1. A rock built up from fragments deposited in water and later cemented
  2. A rock formed by the compaction of plant remains under pressure
  3. A rock changed in form by great heat and pressure without melting
  4. A rock formed by the cooling and solidification of molten material Correct answer.

Explanation

Igneous rocks originate from magma or lava that cools and crystallises. Slow cooling underground gives coarse crystals such as granite, while rapid cooling at the surface gives fine-grained rock such as basalt.

Question 29Physical Geography: Earth's Interior, Rocks, and Landforms

Basaltic magma is generally less viscous than granitic magma. Which consequence follows most directly from this difference?

  1. Basaltic eruptions always produce thick ash columns
  2. Granitic magma flows farther before solidifying
  3. Granitic eruptions rarely build steep-sided cones
  4. Basaltic eruptions tend to be quieter and spread lava farther Correct answer.

Explanation

Lower viscosity means dissolved gases escape more easily and lava flows more freely. Basaltic volcanoes therefore often erupt quietly and build broad shield cones, whereas viscous granitic magma traps gas and erupts explosively.

Question 30Physical Geography: Earth's Interior, Rocks, and Landforms

A geologist finds a rock made of well-rounded, sorted quartz grains cemented together. Which interpretation of its history is most reasonable?

  1. The rock was recrystallised under high pressure
  2. The grains were transported far by water before deposition Correct answer.
  3. The grains cooled quickly from lava at the surface
  4. The grains were dropped directly from a melting glacier

Explanation

Rounded, well-sorted grains indicate prolonged transport by water, which wears off corners and separates grains by size. Such a sandstone is therefore typical of a river, beach or shallow sea environment.

Question 31Physical Geography: Earth's Interior, Rocks, and Landforms

In the rock cycle, which pair of processes turns an exposed igneous rock into a sedimentary rock?

  1. Compression that folds the layers without breaking them
  2. Melting, then slow cooling underground
  3. Heat and pressure acting without melting
  4. Weathering and erosion, then deposition and cementation Correct answer.

Explanation

Sedimentary rocks form at the surface: existing rock is broken down by weathering, the debris is eroded and transported, then deposited and lithified by compaction and cementation. Melting or intense heat and pressure would lead to igneous or metamorphic rocks instead.

Question 32Physical Geography: Earth's Interior, Rocks, and Landforms

Seismic records show that S-waves cannot pass through the outer core. What does this observation indicate about the outer core?

  1. It behaves as a liquid, since shear waves cannot travel through fluids Correct answer.
  2. It is solid but extremely hot
  3. It is composed entirely of silicate minerals
  4. It is denser than the inner core

Explanation

S-waves are shear waves and cannot propagate through liquids, so their disappearance beyond the outer core shows that this zone is liquid. P-waves still pass through it, though they are refracted, which confirms the core's different composition and density.

Question 33Physical Geography: Earth's Interior, Rocks, and Landforms

Which of the following is the most direct evidence that the Earth's core is composed largely of iron and nickel?

  1. The shape of folded mountain belts
  2. The composition of iron meteorites and the Earth's overall density Correct answer.
  3. The colour of lava erupted at mid-ocean ridges
  4. The thickness of sedimentary layers in ocean basins

Explanation

Iron meteorites are thought to be fragments of differentiated planetary cores, and the Earth's average density requires a very dense metallic core. Together with seismic data, this supports an iron-nickel core. Surface features such as lava colour or fold belts say nothing directly about core composition.

Question 34Physical Geography: Earth's Interior, Rocks, and Landforms

A river enters a lake and its velocity suddenly falls. Which change in its transported load is most likely?

  1. The load is dissolved completely and leaves no deposit
  2. Coarse gravel is dropped first, then finer sand and silt farther out Correct answer.
  3. All sediment is carried across the lake without settling
  4. Fine clay settles first, followed by gravel

Explanation

A river's capacity to carry material depends on its velocity. When flow slows, the heaviest and coarsest particles settle first near the mouth, and progressively finer material is deposited farther out, producing graded deposits.

Question 35Physical Geography: Earth's Interior, Rocks, and Landforms

Which statement best explains why the Himalayas are still rising even though folding has already built them?

  1. River erosion is depositing sediment on the peaks
  2. Glaciers are pushing rock upward from the valleys
  3. Continental collision continues to shorten and thicken the crust Correct answer.
  4. The mountains are being uplifted by tidal forces

Explanation

The Himalayas lie at a convergent boundary where the Indian plate continues to push into the Eurasian plate. This ongoing collision compresses and thickens the crust, so uplift continues while erosion simultaneously wears the range down.

Question 36Physical Geography: Earth's Interior, Rocks, and Landforms

Two sites lie at the same distance from an earthquake epicentre, but one is on soft alluvium and the other on hard granite. Which explanation best accounts for the greater shaking on the alluvium?

  1. Granite transmits no seismic waves at all
  2. Granite reflects all seismic energy back into the mantle
  3. Loose saturated sediment amplifies ground motion and may liquefy Correct answer.
  4. Soft alluvium lies closer to the focus than granite does

Explanation

Loose, water-saturated sediment can amplify certain seismic waves and lose strength through liquefaction, so buildings on it suffer more. Hard bedrock transmits waves with less amplification, which is why local geology strongly modifies earthquake damage.

Question 37Atmosphere: Composition, Insolation, Temperature, Pressure, Winds, and Precipitation

Which gas forms the largest proportion of the atmosphere by volume near the Earth's surface?

  1. Oxygen
  2. Nitrogen Correct answer.
  3. Carbon dioxide
  4. Argon

Explanation

Dry air near the surface is about 78 percent nitrogen and 21 percent oxygen by volume, so nitrogen is by far the most abundant constituent. Oxygen is second, while argon is under 1 percent and carbon dioxide is only about 0.04 percent.

Question 38Atmosphere: Composition, Insolation, Temperature, Pressure, Winds, and Precipitation

In which layer of the atmosphere do most weather phenomena such as clouds and rainfall occur?

  1. Troposphere Correct answer.
  2. Stratosphere
  3. Mesosphere
  4. Thermosphere

Explanation

The troposphere holds nearly all atmospheric water vapour and is where temperature falls with height, producing convection, clouds and precipitation. The stratosphere, mesosphere and thermosphere are far drier and do not host ordinary weather systems.

Question 39Atmosphere: Composition, Insolation, Temperature, Pressure, Winds, and Precipitation

What is insolation in the study of the atmosphere?

  1. Heat radiated outward from the Earth's surface at night
  2. The transfer of heat by rising air currents
  3. The reflection of sunlight by clouds and ice
  4. Incoming solar radiation received at the Earth's surface Correct answer.

Explanation

Insolation means incoming solar radiation, the shortwave energy from the Sun that reaches the Earth's surface and atmosphere. It is the ultimate source of energy driving temperature, pressure and wind systems.

Question 40Atmosphere: Composition, Insolation, Temperature, Pressure, Winds, and Precipitation

Atmospheric pressure decreases with increasing altitude mainly because

  1. gravity becomes stronger at higher elevations
  2. the weight of the overlying air column becomes smaller Correct answer.
  3. temperature always rises with height in the troposphere
  4. the proportion of oxygen in the air rises with height

Explanation

Pressure is the weight of the air column above a point, so as altitude increases the column shortens and pressure falls. Air also becomes less dense with height, reinforcing the decline.

Question 41Atmosphere: Composition, Insolation, Temperature, Pressure, Winds, and Precipitation

Which instrument is used to measure atmospheric pressure?

  1. Rain gauge
  2. Barometer Correct answer.
  3. Anemometer
  4. Hygrometer

Explanation

A barometer measures atmospheric pressure, commonly in millibars or hectopascals. Hygrometers measure humidity, anemometers measure wind speed and rain gauges measure precipitation.

Question 42Atmosphere: Composition, Insolation, Temperature, Pressure, Winds, and Precipitation

Which of the following is a form of precipitation?

  1. Fog
  2. Frost
  3. Dew
  4. Hail Correct answer.

Explanation

Precipitation is water that falls from clouds to the ground, and hail is a solid form of it. Dew, frost and fog form by condensation or deposition near the surface and do not fall from clouds.

Question 43Atmosphere: Composition, Insolation, Temperature, Pressure, Winds, and Precipitation

Lines drawn on a map joining places of equal atmospheric pressure are called

  1. contours
  2. isotherms
  3. isobars Correct answer.
  4. isohyets

Explanation

Isobars connect points of equal pressure and their spacing shows the pressure gradient. Isotherms join equal temperatures, isohyets join equal rainfall and contours join equal elevation.

Question 44Atmosphere: Composition, Insolation, Temperature, Pressure, Winds, and Precipitation

The process by which water changes from vapour to liquid droplets in the atmosphere is called

  1. sublimation
  2. condensation Correct answer.
  3. evaporation
  4. transpiration

Explanation

Condensation is the change of water vapour into liquid water, usually on tiny particles called condensation nuclei, and it is essential for cloud formation. Evaporation and transpiration add vapour, while sublimation changes ice directly to vapour or the reverse.

Question 45Atmosphere: Composition, Insolation, Temperature, Pressure, Winds, and Precipitation

Why are the tropics warmer than the poles throughout the year?

  1. Solar rays strike the tropics more vertically, concentrating energy Correct answer.
  2. The tropics receive more hours of darkness each year
  3. The poles reflect less sunlight than the tropics
  4. The tropics are closer to the Sun than the poles are

Explanation

Near the equator the Sun's rays fall almost vertically, so a given amount of solar energy is concentrated on a small surface area. At high latitudes the same rays strike at a slant and spread over a larger area, giving less heating.

Question 46Atmosphere: Composition, Insolation, Temperature, Pressure, Winds, and Precipitation

The temperature range between day and night is usually greatest in a desert because

  1. the high humidity traps heat throughout the night
  2. the desert atmosphere is dense and holds much water vapour
  3. deserts receive no insolation during the daytime
  4. clear skies allow rapid heating by day and rapid radiation loss at night Correct answer.

Explanation

Deserts have dry, clear air with little cloud or water vapour. Strong insolation heats the ground by day, and with no cloud blanket to trap outgoing radiation the surface loses heat rapidly at night, producing a large diurnal range.

Question 47Atmosphere: Composition, Insolation, Temperature, Pressure, Winds, and Precipitation

A place records a maximum temperature of 34 degrees Celsius and a minimum of 18 degrees Celsius on the same day. What is its diurnal temperature range?

  1. 16 degrees Celsius Correct answer.
  2. 8 degrees Celsius
  3. 52 degrees Celsius
  4. 26 degrees Celsius

Explanation

The diurnal range is the maximum minus the minimum temperature for the day, so 34 minus 18 equals 16 degrees Celsius. Adding the values or halving them does not give the range.

Question 48Atmosphere: Composition, Insolation, Temperature, Pressure, Winds, and Precipitation

On a standard pressure map, closely spaced isobars indicate

  1. a weak pressure gradient and calm conditions
  2. a region of permanently rising air
  3. a steep pressure gradient and strong winds Correct answer.
  4. uniform pressure over a wide area

Explanation

When isobars are close together the pressure changes rapidly over a short distance, giving a steep pressure gradient. Since wind speed depends on the pressure gradient force, strong winds are expected in such areas.

Question 49Atmosphere: Composition, Insolation, Temperature, Pressure, Winds, and Precipitation

Air flows from a high-pressure area to a low-pressure area primarily because of

  1. the Coriolis force
  2. the pressure gradient force Correct answer.
  3. frictional drag at the surface
  4. the rotation of the Earth on its axis

Explanation

The pressure gradient force pushes air from higher pressure toward lower pressure and is the fundamental cause of wind. The Coriolis force only deflects moving air and friction only slows it.

Question 50Atmosphere: Composition, Insolation, Temperature, Pressure, Winds, and Precipitation

In the Northern Hemisphere, the Coriolis force deflects moving air to the

  1. centre of the nearest low-pressure system
  2. left of its direction of motion
  3. right of its direction of motion Correct answer.
  4. direction of the pressure gradient

Explanation

Because of the Earth's rotation, winds in the Northern Hemisphere are deflected to the right of their path, while in the Southern Hemisphere they are deflected to the left. This deflection shapes the circulation around pressure systems.