Climatology - 2 - Free MCQ Practice Test with solutions, UPSC Geography

1 and 2 only

Statement 1 is correct. At about 20°-30° N/S the persistent subtropical high-pressure belts produce large-scale descending air. Descending air undergoes adiabatic warming, which increases its moisture-holding capacity and suppresses cloud formation and precipitation, producing arid conditions.

Statement 2 is correct. The prevailing trade winds in these latitudes tend to be offshore along western continental margins, so moist onshore flow from the ocean is limited. As a result, these winds do not transport significant oceanic moisture inland to generate rainfall, contributing to dryness.

Statement 3 is incorrect. Instead of warm currents, most western subtropical coasts are influenced by cold ocean currents (for example, the Canary, Benguela, Humboldt and West Australian currents). Cold currents cool the overlying air, reduce evaporation and stabilize the lower atmosphere, further inhibiting precipitation; a warm current would tend to enhance evaporation and precipitation, so the presence of warm currents is not a cause of these deserts.

Hence the correct combination is 1 and 2 only.

A: 1 only

Statement 1 - Correct. The Equator and the associated ITCZ receive the highest mean rainfall because strong solar heating causes convectional rainfall and persistent upward motion. Moving poleward the mean precipitation falls overall, largely because of the subtropical high-pressure belts (≈20°-30°) where air subsidence suppresses rainfall. (There are regional departures from this simple trend - for example, increased precipitation in the mid-latitudes from cyclonic activity - but the broad latitudinal decline from equator toward the poles is the standard pattern taught in NCERT/CBSE/NEET contexts.)

Statement 2 - Incorrect. In the 35°-40° latitudinal belt western continental margins are generally drier because of the influence of subtropical highs and often cold ocean currents (examples: parts of coastal California, coastal Peru, Namib coast). Eastern margins at those latitudes commonly receive more moisture (humid subtropical or monsoonal influences) and therefore tend to be wetter.

Statement 3 - Incorrect. In the 45°-65° belt the prevailing westerlies transport moist maritime air onto the western margins of continents, producing higher rainfall on western coasts (examples: western Europe, the Pacific north-west, western New Zealand) than on the eastern margins.

Therefore, only Statement 1 is correct.

C: 1, 2 and 3 only

Statements 1, 2 and 3 are correct; statement 4 is incorrect.

Köppen Group B denotes Dry Climates, which are diagnosed by a persistent precipitation deficit relative to potential evapotranspiration rather than by temperature alone. Group B is divided into BS (steppe, semi-arid) and BW (desert, arid) categories.

Statement 1 corresponds to the hot/semi-arid subtype (BSh) and is therefore a Dry Climate - correct.

Statement 2 corresponds to the cold/continental semi-arid subtype (BSk) and is also a Dry Climate - correct.

Statement 3 corresponds to desert subtypes (BWh, BWk) and is a Dry Climate - correct.

Statement 4 refers to Mediterranean climates, which belong to Group C (Csa, Csb) - temperate climates with dry summers but not classified as Group B dry climates, so it is incorrect.

The correct answer is Option D - All four

• Statement 1 is correct because a sustained sea surface temperature above 26.5°C is a basic requirement for tropical cyclogenesis; the more enclosed basin heats more easily and maintains higher surface temperatures, which favour the development of low-pressure systems.

• Statement 2 is correct because a relatively shallower embayment warms faster and has reduced vertical mixing, contributing to higher surface temperatures and greater instability in the lower atmosphere, both of which aid cyclone formation.

• Statement 3 is correct because abundant moisture in the near-surface air increases condensation and release of latent heat, sustaining deep convection and intensification of developing disturbances.

• Statement 4 is correct because atmospheric disturbances and pulses originating in the tropical Pacific can propagate across the Maritime Continent into the eastern Indian Ocean and act as seeds for cyclonic development; such external forcing reaches the eastern basin more readily than the western basin, increasing the frequency of disturbances there.

All four statements therefore together explain the generally higher frequency of cyclones in the eastern basin compared with the western basin.

C: Statement I is correct, but Statement II is incorrect.

The vertical pressure gradient is very large because atmospheric pressure decreases rapidly with height (for example, from 1013 hPa at sea level to about 500 hPa by 5.5 km). In the vertical the pressure gradient per unit mass is effectively equal to gravity, giving an acceleration of about g ≈ 9.8 m/s^2.

By contrast, typical horizontal pressure differences are small: e.g., 20 hPa over 1000 km corresponds to a horizontal pressure gradient of about 0.002 Pa/m, which produces a horizontal acceleration of order 1.7×10^-3 m/s^2 (using air density ≈ 1.2 kg/m^3). Thus the vertical pressure-gradient force is on the order of ~6000 times larger than typical horizontal pressure-gradient forces.

However, the vertical pressure-gradient force is not balanced by friction. The correct balance is hydrostatic equilibrium, expressed as dp/dz = -ρg, meaning the upward pressure-gradient force per unit mass is balanced by the downward force of gravity. Friction primarily acts on horizontal motion in the boundary layer and does not provide the primary balance for the large vertical pressure-gradient force; when hydrostatic balance locally breaks (e.g., strong convection), buoyancy and accelerations-not surface friction-control the vertical motion.

Only two

Statement 1 is correct. The apparent deflecting acceleration in a rotating frame has magnitude given by 2Ωv sinφ (for horizontal motion), where Ω is Earth's angular speed, v the object's speed and φ the latitude. At φ = 0° the factor sinφ = 0 so the Coriolis effect vanishes; at φ = 90° the factor is unity and the effect is maximal.

Statement 2 is incorrect. The Coriolis effect is due to Earth's rotation about its axis and arises when using a rotating (non-inertial) reference frame. Earth's revolution around the Sun is a separate orbital motion (with period one year) and is not the cause of the everyday Coriolis deflection.

Statement 3 is correct. From the expression for the Coriolis force F = 2mΩv sinφ, the magnitude is proportional to the object's speed v (and to its mass m), so faster moving bodies experience a larger Coriolis force; for very slow motions the effect is negligible.

Only one

Statement 1 - Correct. The Earth's planetary albedo is about 0.30 (≈30%), so roughly one-third of incoming solar radiation is reflected back to space.

Statement 2 - Incorrect. In the global energy budget the surface absorbs more solar energy than the atmosphere: of the mean solar input (~340 W/m² at the top of atmosphere), about 161 W/m² (≈47%) is absorbed by the surface while the atmosphere and clouds absorb about 79 W/m² (≈23%).

Statement 3 - Incorrect (misleading). The greenhouse effect arises because greenhouse gases absorb and re-emit the Earth's outgoing longwave (thermal infrared) radiation, not the bulk of incoming shortwave solar radiation. (There are exceptions: ozone absorbs solar UV in the stratosphere and water vapor absorbs some near-IR, but these do not constitute the primary greenhouse mechanism.)

Therefore, only the first statement is correct.

C: Both 1 and 2

Statement 1 is correct. Frontal (extratropical) cyclones are low-pressure systems that develop in the mid-latitudes (temperate regions) along the polar front, where relatively warm and cold air masses converge. These systems produce warm and cold fronts, strong temperature gradients, and associated frontal precipitation as the different air masses interact.

Statement 2 is also correct. The Mediterranean region has a climate dominated by a subtropical high in summer (producing hot, dry conditions), while in winter the westerlies and the storm track shift equatorward so that incoming extratropical (frontal) cyclones deliver most of the region's winter rainfall.

2 only

Statement 1 - Incorrect. Jet streams are narrow, fast air currents found primarily in the upper troposphere near the tropopause, but they often extend into the lower stratosphere or vary in altitude with season and latitude, so they are not restricted only to the troposphere.

Statement 2 - Correct. The Tropical Easterly Jet (TEJ), a summer easterly in the upper troposphere over the Indian region, promotes upper-level divergence and supports the monsoon circulation and the development/intensification of the monsoon trough (ITCZ shift) over the Indian subcontinent.

Statement 3 - Incorrect. The dominant mid-latitude jets in the Northern Hemisphere flow predominantly west-to-east (associated with the westerlies); seasonal easterly jets like the TEJ are exceptions rather than the general rule.

Conclusion: only statement 2 is correct.

Inter-Tropical Convergence Zone (ITCZ) - a near-equatorial belt of persistent low pressure where surface trade winds from the Northern and Southern Hemispheres meet; intense solar heating there causes warm, moisture-laden air to ascend, producing strong convection, widespread cloudiness and frequent heavy precipitation.

The position of the ITCZ shifts seasonally toward the warmer hemisphere, which helps govern the timing and intensity of tropical rainfall and is closely related to regional features such as the monsoon trough during peak monsoon seasons.

By contrast, the subtropical high-pressure belt is characterized by descending air and clear, dry conditions (subsidence), while the subpolar low-pressure belt is a mid-latitude zone of instability associated with cyclones; neither produces the persistent, near-equatorial upward motion and deep convection that define the ITCZ.

2 only

Statement 1 is incorrect. During El Niño the central and eastern tropical Pacific become anomalously warm, shifting convection eastward and weakening the normal rising motion over the western Pacific and Indonesia. This produces drier conditions there and increases the risk of droughts and bush/forest fires, not a decreased incidence.

Statement 2 is correct. The anomalous warming of the central/eastern Pacific raises local sea surface temperatures and convection, which tends to increase the frequency and intensity of tropical cyclones in the central/eastern Pacific basin (while typically suppressing activity in the Atlantic basin).

Statement 3 is incorrect. El Niño generally disrupts the tropical Walker circulation and reduces the moisture inflow and convective activity over the Indian subcontinent, tending to weaken the Indian summer monsoon (whereas La Niña tends to support stronger monsoon rainfall).

Both Statement-I and Statement-II are correct and Statement-II is the correct explanation for Statement-I.

Temperature inversion is a situation where air temperature increases with height in the lower atmosphere, opposite to the normal lapse rate (≈ 6.5°C per km). Intermontane valleys commonly experience inversions on clear, calm winter nights because the valley geometry and nocturnal conditions favor trapping cold air near the ground.

At night the mountain slopes cool rapidly by radiative cooling. The chilled, denser air slides downhill under gravity as katabatic winds and pools in the valley bottom (cold-air pooling). This cold layer at the surface underlies warmer air above, producing the inversion and suppressing vertical mixing, so Statement-II correctly explains why Statement-I occurs.

Typical consequences include persistent fog, frost, and degraded air quality in the valley bottoms until daytime heating or stronger winds erode the inversion and restore normal lapse-rate conditions.

China type climate: This climate occurs on the eastern continental margins of the subtropics and lower mid-latitudes and is characterized by a humid subtropical, monsoon-influenced pattern - warm, humid summers due to maritime onshore flow and relatively cool, dry winters under continental air masses.

Such conditions favor paddy rice cultivation on irrigated lowlands and slope terraces, and the growth of tea, mulberry (for silk production), and other moisture-demanding crops. The natural vegetation is typically mixed forests with both deciduous and evergreen tree species.

Why the other types are incorrect: the British type climate is a cool temperate oceanic climate with mild winters and no extreme summer heat needed for silk/tea; the Mediterranean climate has dry summers and wet winters (the opposite seasonal rainfall pattern); and the Steppe climate is semi-arid with low rainfall and grassland vegetation, unsuitable for the moisture-loving crops listed.

Monsoon with dry winter (Cwg)

The Gangetic plains are best described by the Köppen classification category that denotes a temperate/mesothermal climate with a dry winter and a hot summer. The standard Köppen symbol for this climate is Cwa - C = temperate (mesothermal), w = dry winter, a = hot summer. This reflects the plains' hot summers (peak temperatures often exceeding 40°C in places), a pronounced southwest monsoon rainfall season (mainly June-September), and relatively dry winters with much lower precipitation.

Why the other symbols are incorrect: As (monsoon with dry summer) implies a dry summer, which is not true here; Aw (tropical savannah) refers to tropical areas with year-round high temperatures and a distinct wet/dry season typical of some peninsular regions, not the subtropical Gangetic plain; and Dfc describes subarctic climates with long, very cold winters and short summers, which do not occur in the Gangetic plains.

In short, the correct Köppen code used in standard references for the Gangetic plains is Cwa (monsoon-influenced humid subtropical - dry winter, hot summer), closely matching the intended meaning of the supplied option.

Row 1 is correct. Cirrus are high clouds composed of ice crystals, typically found around 8-12 km; they are thin, feathery and appear white.

Row 2 is incorrect. While the description of a cotton-wool appearance with a flat base correctly describes Cumulus, these are generally low-level clouds (bases often around 1-2 km), not middle-level clouds.

Row 3 is correct. The term nimbus refers to rain-bearing clouds (e.g., nimbostratus, cumulonimbus) that are dense, dark and often opaque to sunlight, occurring at low to mid levels and producing precipitation.

Therefore, exactly two rows are correctly matched (Rows 1 and 3).

A: 1 only

Statement 1 - Correct. Jet streams are narrow, fast-flowing bands of air in the upper troposphere located near the tropopause. They form along strong horizontal temperature gradients between air masses, producing strong geostrophic winds. Typical altitudes are about 7-16 km (for example, the polar jet roughly 7-12 km and the subtropical jet roughly 10-16 km), and speeds commonly reach 100-400 km/h.

Statement 2 - Incorrect. The dominant motion of jet streams in both hemispheres is from west to east (they are westerlies), driven by the temperature-driven pressure gradients and the Coriolis effect. While jets can meander as Rossby waves and exhibit local directional changes, their general flow is not from east to west.

Therefore, only the first statement is correct.

B: Both Statement I and Statement II are correct but Statement II does not explain Statement I

Statement I is true.Solar noon is the instant when the Sun crosses an observer's local meridian and attains its maximum altitude; the timing of this instant is governed by the observer's longitude because the Earth rotates eastward, causing places to the east to experience solar noon earlier than places to the west.

Geographical coordinates show that Kolkata is east of Chennai: Kolkata ≈ 22.57° N, 88.36° E, Chennai ≈ 13.08° N, 80.27° E. Because Kolkata has the larger eastward longitude, its solar noon occurs earlier than Chennai's.

Statement II is true. The latitudes above show Kolkata (~22.57° N) lies at a greater northern latitude than Chennai (~13.08° N).

However, the difference in latitude does not cause the difference in solar noon timing. Solar noon depends on longitude, while latitude affects the Sun's maximum altitude and seasonal daylight variation. Therefore Statement II does not explain Statement I.

Statement 1 is correct. Typical temperature at the tropopause is about -55°C, while near the stratopause it is approximately 0°C, so the mean temperature near the stratopause is higher than near the tropopause.

Statement 2 is incorrect. Most atmospheric ozone is concentrated in the stratosphere, but measurable ozone also exists in the troposphere (where it acts as a pollutant) and in trace amounts elsewhere; the stratosphere is not the sole layer with ozone.

Statement 3 is incorrect. The vertical sequence of major layers from the surface upward is troposphere → stratosphere → mesosphere → thermosphere, so the mesosphere lies immediately above the stratosphere.

Therefore, the incorrect statements are 2 and 3, which corresponds to option B.

C: Both 1 and 2

Statement 1 is correct. Thunderstorms are vigorous convective storms built around towering cumulonimbus clouds. They develop when warm, moist air rises in an unstable atmosphere, generating strong updrafts, condensation and release of latent heat that sustains the convection. Charge separation within the cloud produces lightning, and the rapid heating and expansion of air from lightning produces thunder.

Statement 2 is correct. Hail forms in tall convective (cumulonimbus) clouds whose tops or parts extend above the freezing level into sub-zero temperatures. In the cloud's mixed-phase region, supercooled water droplets freeze on ice nuclei or riming particles; strong updrafts keep these particles aloft so they grow by accretion and repeated cycling through the freezing zone, producing layered or concentric ice stones that fall when their weight overcomes the updraft.

C: All three

All three statements are true.

Statement 1 is true. The Sun can be at the local zenith only for latitudes between the two Tropics (between the Tropic of Cancer and the Tropic of Capricorn), because the Sun's declination oscillates between about +23.5° and -23.5° over the year; locations outside that band never receive the Sun exactly overhead.

Statement 2 is true. If Earth's axis were perpendicular to its orbital plane (i.e., axial tilt = 0°), there would be no seasonal tilt toward or away from the Sun, so the day-night dividing line (the terminator) would always be a great circle and every place on Earth would have about 12 hours of daylight and 12 hours of night every day.

Statement 3 is true. At an equinox the axis is neither tilted toward nor away from the Sun, so neither pole tilts toward the Sun; the Sun lies over the equator and day and night are approximately equal globally.