Atmospheric Pressure & Planetary Winds – NDA Geography PYQs

NDA 2023-I

Q. 1. Which one of the following is a cold local wind?

(a) Foehn

(b) Mistral

(c) Sirocco

(d) Chinook

Answer: (b) Mistral

Explanation: Mistral is a cold, dry, northerly wind that blows through the Rhône Valley in southern France toward the Mediterranean Sea. It is one of the most well-known cold local winds. Foehn (a): warm, dry wind on the leeward side of the Alps (Switzerland/Austria). Föhn effect = warm wind. Sirocco (c): hot, dry or moist wind from the Sahara blowing northward toward the Mediterranean; very hot. Chinook (d): warm, dry wind on the eastern (leeward) side of the Rocky Mountains (Canada/USA). Causes rapid temperature rise. Concept Tested: Mistral: cold northerly wind in southern France (Rhône Valley); Foehn, Sirocco, Chinook are warm/hot winds

★ JOVIK Exam Insight Local winds for NDA: warm vs. cold: Warm local winds: Foehn/Föhn (Alps), Chinook (Rockies/Canada), Sirocco (Sahara→Mediterranean), Khamsin (Egypt), Zonda (Argentina), Santa Ana (California). Cold local winds: Mistral (France), Bora (Adriatic), Blizzard (USA/Canada), Purga (Siberia), Harmattan (West Africa: dry, dusty from Sahara; cool relative to coast).

NDA 2022-II

Q. 2. Consider the following statements about fronts:

1. A warm front is one where warm air replaces cold air.

2. A cold front is one where cold air replaces warm air.

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Answer: (c) Both 1 and 2

Explanation: Statement 1: Correct. A warm front is the leading edge of an advancing warm air mass. As it moves, warm air replaces cold air in its path. Warm fronts produce steady, continuous rainfall over a wide area. Statement 2: Correct. A cold front is the leading edge of an advancing cold air mass. As cold air advances, it undercuts and lifts the warm air ahead of it. Cold fronts produce short, intense rainfall (sometimes thunderstorms). Concept Tested: Fronts: warm front (warm replaces cold; steady rain); cold front (cold replaces warm; intense brief rain)

NDA 2021-I

Q. 3. Consider the following statements about tropical cyclones:

1. Tropical cyclones have warm core.

2. Tropical cyclones have no fronts.

3. Tropical cyclones have cold core.

Which of the statements given above is/are correct?

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1, 2 and 3

(d) 1 and 3 only

Answer: (a) 1 and 2 only

Explanation: Statement 1 (Warm core): Correct. Tropical cyclones derive energy from warm ocean water and latent heat release. The centre is warmer than the surrounding environment: warm core. Statement 2 (No fronts): Correct. Tropical cyclones form within a single warm, moist tropical air mass. Unlike extratropical cyclones, they do NOT develop fronts. Statement 3 (Cold core): Incorrect. Tropical cyclones have a WARM core, not a cold core. Extratropical/temperate cyclones have cold cores. Concept Tested: Tropical cyclones: warm core AND no fronts (correct); cold core is WRONG: that describes extratropical cyclones

NDA 2020-I

Q. 4. Which of the following statements about El Niño and La Niña is/are correct?

1. El Niño is associated with above-normal sea surface temperatures in the central and eastern tropical Pacific Ocean.

2. La Niña is associated with below-normal sea surface temperatures in the central and eastern tropical Pacific Ocean.

Select the correct answer using the code given below:

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Answer: (c) Both 1 and 2

Explanation: Statement 1: Correct. El Niño is a climate pattern in which sea surface temperatures in the central and eastern tropical Pacific Ocean are ABOVE normal. This disrupts normal atmospheric circulation, reducing Indian monsoon rainfall and causing droughts in Australia and Southeast Asia. Statement 2: Correct. La Niña is the opposite: sea surface temperatures in the same region are BELOW normal. La Niña typically enhances the Indian monsoon (more rainfall) and increases rainfall in Australia and Southeast Asia. Concept Tested: El Niño = warm Pacific (above normal SST); La Niña = cool Pacific (below normal SST): both correct

NDA 2019-I

Q. 5. Which one of the following is correct regarding anticyclones?

(a) They are regions of low pressure

(b) They produce stormy weather

(c) Wind circulation is counterclockwise in the Northern Hemisphere

(d) They produce clear, dry weather

Answer: (d) They produce clear, dry weather

Explanation: Anticyclones are regions of HIGH pressure where air DESCENDS and diverges outward. Descending air warms and dries (inhibiting cloud formation), producing clear, dry, settled weather. (a): Incorrect. Anticyclones = HIGH pressure. (b): Incorrect. Stormy weather is associated with CYCLONES (low pressure). (c): Incorrect. In the NH, anticyclone winds rotate CLOCKWISE (not counterclockwise). (d): Correct. Anticyclones produce calm, clear, dry weather. Concept Tested: Anticyclone: high pressure; descending dry air; clear, calm weather (NOT stormy); clockwise in NH

NDA 2018-II

Q. 6. Which one of the following is the correct sequence of jet streams from the Equator to the Pole?

(a) Subtropical Jet Stream, Polar Front Jet Stream

(b) Polar Front Jet Stream, Subtropical Jet Stream

(c) Subtropical Jet Stream, Polar Easterly Jet Stream

(d) Polar Front Jet Stream, Subtropical Jet Stream, Polar Easterly Jet Stream

Answer: (a) Subtropical Jet Stream, Polar Front Jet Stream

Explanation: Jet streams are fast-flowing, narrow air currents in the upper troposphere/lower stratosphere. From equator to pole, the main jet streams are: Subtropical Jet Stream: located at about 25°–30°N and 25°–30°S; typically at 12–14 km altitude; speeds ~120–200 km/h. Polar Front Jet Stream: located at about 50°–60°N and 50°–60°S; associated with the polar front; strongest in winter. Moving from equator toward the pole: Subtropical Jet Stream → Polar Front Jet Stream. Concept Tested: Jet stream sequence from equator to pole: Subtropical Jet Stream → Polar Front Jet Stream

NDA 2018-I

Q. 7. Thunderstorms are usually associated with which type of cloud?

(a) Stratus

(b) Cirrus

(c) Cumulonimbus

(d) Cumulus

Answer: (c) Cumulonimbus

Explanation: Cumulonimbus clouds are the clouds associated with thunderstorms. They are massive, vertically developed clouds that can extend from near the surface to the tropopause (up to 15 km height in the tropics). They produce: 1. Heavy rain and hail. 2. Lightning and thunder. 3. Gusty winds and sometimes tornadoes. Stratus (a): low, layered clouds producing drizzle. Cirrus (b): high, thin, wispy clouds made of ice crystals. Cumulus (d): fair-weather puffy clouds (without storm development). Concept Tested: Cumulonimbus: the cloud type associated with thunderstorms, lightning, heavy rain, hail

NDA 2017-II

Q. 8. Which type of rainfall is associated with the windward slopes of mountain ranges?

(a) Orographic rainfall

(b) Cyclonic rainfall

(c) Convectional rainfall

(d) Frontal rainfall

Answer: (a) Orographic rainfall

Explanation: Orographic (relief) rainfall is directly associated with windward slopes of mountain ranges. Moist air is forced to rise on the windward side, cools, condenses, and deposits rain. The leeward side (rain shadow) receives much less rainfall. Examples: Western Ghats windward side (Kerala, coastal Maharashtra) receives 200–300+ cm of rainfall, while the leeward side (e.g., Deccan plateau) receives 50–70 cm. Concept Tested: Orographic rainfall: associated with windward slopes of mountains; leeward side has rain shadow

NDA 2017-I

Q. 9. The Beaufort scale is used to measure:

(a) Rainfall intensity

(b) Earthquake intensity

(c) Wind speed

(d) Atmospheric pressure

Answer: (c) Wind speed

Explanation: The Beaufort Scale is an empirical measure of wind speed, developed by British Admiral Sir Francis Beaufort in 1805. It ranges from Force 0 (calm, < 1 km/h) to Force 12 (hurricane-force, > 117 km/h). It is widely used in meteorology, particularly for marine weather reports. Other measurement scales: Richter/Moment Magnitude → earthquake magnitude; Mercalli → earthquake intensity; Saffir-Simpson → hurricane category. Concept Tested: Beaufort Scale: measures wind speed (Force 0 to 12); developed by Admiral Beaufort in 1805

NDA 2016-II

Q. 10. Which one of the following is not a warm ocean current?

(a) Gulf Stream

(b) Kuroshio Current

(c) Brazil Current

(d) California Current

Answer: (d) California Current

Explanation: The California Current flows southward along the western coast of North America (California) from north to south. It is a COLD ocean current: it brings cold water from the north. Warm currents: Gulf Stream (a): warm current from Gulf of Mexico flowing north along east coast of USA then northeast toward Europe. Kuroshio (Japan) Current (b): warm current flowing north along eastern coast of Japan. Brazil Current (c): warm current flowing southward along the eastern coast of South America. As a general rule: Western boundary currents (along east coasts of continents) tend to be warm; Eastern boundary currents (along west coasts) tend to be cold. Concept Tested: California Current is a COLD ocean current; Gulf Stream, Kuroshio, Brazil are warm currents

NDA 2016-I

Q. 11. Which one of the following is correct regarding anticyclone?

(a) It is a low pressure system

(b) Winds blow from centre to periphery

(c) Weather is usually stormy

(d) Air flow is counterclockwise in Northern Hemisphere

Answer: (b) Winds blow from centre to periphery

Explanation: An anticyclone is a high pressure system where air diverges (flows outward) from the centre to the periphery. (a): Incorrect. Anticyclone is HIGH pressure (opposite of cyclone which is low pressure). (b): Correct. In an anticyclone, air flows outward from the high pressure centre toward lower pressure at the periphery. (c): Incorrect. Anticyclones bring calm, clear, fair weather: not storms. Cyclones bring stormy weather. (d): Incorrect. In the Northern Hemisphere, anticyclones rotate CLOCKWISE (air diverges to the right due to Coriolis). Counterclockwise is how cyclones rotate in NH. Concept Tested: Anticyclone: high pressure; air diverges from centre; fair weather; clockwise in NH (not counterclockwise)

NDA 2015-II

Q. 12. A tropical cyclone is characterised by which one of the following?

(a) Anti-clockwise winds in the Southern Hemisphere

(b) Anti-clockwise winds in the Northern Hemisphere

(c) Clockwise winds in the Northern Hemisphere

(d) Anti-clockwise winds in both hemispheres

Answer: (b) Anti-clockwise winds in the Northern Hemisphere

Explanation: Tropical cyclones rotate anticlockwise in the Northern Hemisphere due to the Coriolis force deflecting winds to the right: air converging into the low pressure centre spirals anticlockwise. In the Southern Hemisphere, cyclones rotate clockwise (Coriolis deflects to the left there). So tropical cyclones do NOT rotate anticlockwise in both hemispheres: only in the Northern Hemisphere. Concept Tested: Tropical cyclone rotation: anticlockwise in Northern Hemisphere; clockwise in Southern Hemisphere

NDA 2015-I

Q. 13. The Coriolis effect deflects winds to the:

(a) Left in the Northern Hemisphere

(b) Right in the Northern Hemisphere

(c) Right in the Southern Hemisphere

(d) Same direction in both hemispheres

Answer: (b) Right in the Northern Hemisphere

Explanation: The Coriolis effect is caused by Earth’s rotation. It deflects moving objects: To the RIGHT in the Northern Hemisphere. To the LEFT in the Southern Hemisphere. This deflection affects winds, ocean currents, and any moving fluid or object over large distances. In the NH: cyclones spiral anticlockwise (wind turns right as it flows inward); anticyclones spiral clockwise. In the SH: cyclones spiral clockwise; anticyclones spiral anticlockwise. Concept Tested: Coriolis effect: deflects winds to the RIGHT in Northern Hemisphere; to the left in Southern Hemisphere

NDA 2014-II

Q. 14. Which of the following characteristics belong to tropical cyclones?

1. They have no fronts.

2. The vertical extent of the clouds is not limited to the lower troposphere.

3. They have a warm core.

Select the correct answer using the code given below:

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

Answer: (d) 1, 2 and 3

Explanation: Tropical cyclones (hurricanes/typhoons) have all three characteristics: Statement 1 (No fronts): Correct. Unlike temperate (extratropical) cyclones, tropical cyclones do NOT have warm fronts or cold fronts. They form entirely within a warm, moist tropical air mass. Statement 2 (Clouds extend high into troposphere): Correct. Cumulonimbus clouds in tropical cyclones can extend through the entire troposphere: from near surface to the tropopause (~15 km in tropics). Statement 3 (Warm core): Correct. Tropical cyclones are warm-core systems: they derive energy from the warm ocean surface and the latent heat released during condensation. The centre of the storm is warmer than the surrounding environment. Concept Tested: Tropical cyclone characteristics: no fronts, deep cloud towers, warm core; all three correct

NDA 2013-II

Q. 15. Which of the following conditions leads to Frontal or Cyclonic rainfall?

(a) A warm and cold air mass meet each other

(b) Air rises due to intense heating

(c) Air is forced up a mountain barrier

(d) Cold air mass meets another cold air mass

Answer: (a) A warm and cold air mass meet each other

Explanation: Frontal (cyclonic) rainfall occurs at the boundary where a warm air mass and a cold air mass meet. The warmer, less dense air rises above the cooler, denser air. As the warm air rises, it cools, condenses, and precipitates: producing continuous, widespread rainfall over large areas. This type of rainfall is characteristic of temperate regions: particularly in Western Europe, Eastern USA, and the mid-latitudes where polar and tropical air masses interact. Concept Tested: Frontal/cyclonic rainfall: warm and cold air masses meet; warm air rises, cools, condenses; widespread steady rain

★ JOVIK Exam Insight Three types of rainfall for NDA: 1. Convectional: intense heating → air rises → thunderstorms. In equatorial/tropical regions. 2. Orographic (Relief): moist air forced up mountain → windward rain, leeward shadow. 3. Frontal (Cyclonic): warm + cold air mass meet → warm air rises → widespread steady rain. In temperate regions.

NDA 2013-I

Q. 16. Orographic rainfall occurs when moist air:

(a) Rises over a mountain range

(b) Moves from a cold sea surface to a warm land surface

(c) Converges along a front

(d) Rises due to heating of the ground

Answer: (a) Rises over a mountain range

Explanation: Orographic (or relief) rainfall occurs when moisture-laden air is forced to rise up a mountain barrier (an orographic barrier). As the air rises: 1. It expands and cools (adiabatically). 2. Temperature drops to the dew point, and water vapour condenses. 3. Cloud forms and precipitation falls on the windward (uphill) side. The leeward side (the rain shadow) receives very little rainfall. Examples: Western Ghats (Western India), Western slopes of Rockies, Western Alps, Windward sides of Himalayas. Concept Tested: Orographic rainfall: moist air forced upward by mountain barrier; precipitation on windward side; rain shadow on leeward side

NDA 2012-II

Q. 17. Horse Latitudes are associated with:

(a) Subtropical High

(b) Equatorial Low

(c) Sub-polar Low

(d) Polar High

Answer: (a) Subtropical High

Explanation: Horse Latitudes are calm, low-wind belts found at approximately 30°N and 30°S: the subtropical high pressure zones. In these belts, air descends (subsides) from aloft, creating high surface pressure and clear skies. There are no significant surface winds. The origin of the name: sailing ships carrying horses from Europe to the Americas would sometimes become becalmed in these latitudes for long periods. Short of food and water, sailors allegedly threw horses overboard. Concept Tested: Horse Latitudes: subtropical high pressure (~30°N and 30°S); calm winds due to descending air; clear skies

NDA 2012-I

Q. 18. Convectional rainfall is associated with:

(a) Temperate regions

(b) Polar regions

(c) Equatorial or Tropical regions

(d) Tropical deserts

Answer: (c) Equatorial or Tropical regions

Explanation: Convectional rainfall is caused by intense solar heating of the surface, which causes surface air to heat up, rise rapidly, cool, and condense: producing towering cumulonimbus clouds and heavy, brief thunderstorms. It is most prevalent in equatorial and tropical regions (including monsoon regions), where solar heating is intense throughout the year. The tropical rainforests receive most of their rainfall this way: daily afternoon thunderstorms are characteristic. Temperature regions receive more frontal/cyclonic rainfall. Polar regions receive very little precipitation overall. Concept Tested: Convectional rainfall: from intense solar heating causing rising air; most common in equatorial/tropical regions

NDA 2011-II

Q. 19. Consider the following statements:

1. In Northern Hemisphere, cyclones rotate anticlockwise.

2. In Southern Hemisphere, anticyclones rotate anticlockwise.

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Answer: (c) Both 1 and 2

Explanation: Statement 1: Correct. In the Northern Hemisphere, Coriolis force deflects winds to the right. Air flows into a low pressure centre (cyclone): spiralling anticlockwise (counterclockwise) as it converges inward. Statement 2: Correct. In the Southern Hemisphere, Coriolis force deflects winds to the left. Air flows outward from a high pressure centre (anticyclone): spiralling anticlockwise in the SH (opposite to the NH where anticyclones are clockwise). Concept Tested: Cyclone rotation: anticlockwise in NH; anticyclone rotation: anticlockwise in SH; due to Coriolis

NDA 2011-I

Q. 20. Consider the following statements:

1. Tropical cyclone has its eye in the centre with calm conditions.

2. Tropical cyclone has wind speeds of over 120 km/h in the eye wall.

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Answer: (c) Both 1 and 2

Explanation: Statement 1: Correct. The eye of a tropical cyclone is the calm, clear central region of the storm. Within the eye, winds are light and skies may be partly clear. Statement 2: Correct. The eye wall is the ring of towering cumulonimbus clouds immediately surrounding the eye. It is where the most destructive winds occur: typically exceeding 120 km/h (and often much higher in major cyclones). Concept Tested: Tropical cyclone structure: eye (calm centre) and eye wall (highest winds, typically 120+ km/h)

NDA 2010-I

Q. 21. Trade winds are associated with:

(a) Equatorial Low and Polar High

(b) Polar High and Sub-polar Low

(c) Subtropical High and Equatorial Low

(d) Sub-polar Low and Subtropical High

Answer: (c) Subtropical High and Equatorial Low

Explanation: Trade winds blow from the subtropical high pressure belts (~30°N and 30°S) towards the equatorial low pressure belt (ITCZ). In the Northern Hemisphere, the Coriolis force deflects them to the right: making them blow from the NE (Northeast Trade Winds). In the Southern Hemisphere, they are deflected to the left: making them blow from the SE (Southeast Trade Winds). Trade winds are consistent, reliable, and were historically used by merchants (hence “trade” winds). Concept Tested: Trade winds: blow from Subtropical High to Equatorial Low; NE trades in NH, SE trades in SH

NDA 2009-II

Q. 22. ‘Doldrums’ are associated with:

(a) Polar High

(b) Subtropical High

(c) Sub-polar Low

(d) Equatorial Low

Answer: (d) Equatorial Low

Explanation: The Doldrums is the zone of equatorial low pressure (ITCZ: Intertropical Convergence Zone) near the equator, roughly between 5°N and 5°S. In this belt, the trade winds from both hemispheres converge, warm moist air rises (convection), and there are very light or calm surface winds. Sailors historically feared this zone because their sailing ships could be becalmed for days. It is also called the “equatorial calm” and is associated with high humidity, frequent thunderstorms, and variable light winds. Concept Tested: Doldrums: equatorial low pressure zone; calm winds; convergence of trade winds; ITCZ region

★ JOVIK Exam Insight Pressure belts and associated wind zones for NDA: Equatorial Low (0°) → Doldrums (calm, rising air, ITCZ). Subtropical High (~30°) → Horse Latitudes (calm, subsiding air). Sub-polar Low (~60°) → Frontal zone; storms; temperate cyclones. Polar High (~90°) → Polar Easterlies blow from poles. Between Subtropical High and Equatorial Low → Trade winds. Between Subtropical High and Sub-polar Low → Westerlies.

NDA 2009-I

Q. 23. ‘Roaring Forties’ refers to:

(a) Trade winds near Equator

(b) Westerlies in the Southern Hemisphere

(c) Polar Easterlies

(d) Monsoon winds

Answer: (b) Westerlies in the Southern Hemisphere

Explanation: “Roaring Forties” refers to the strong, persistent westerly winds in the Southern Hemisphere between approximately 40°S and 50°S. The Southern Ocean in this zone is largely unobstructed by land, allowing the westerlies to blow with great force. Similar zones: “Furious Fifties” (~50°S–60°S) and “Screaming Sixties” (~60°S–70°S). The terms originated from the experiences of sailors in the 18th and 19th centuries who used these winds to sail from Europe to Asia via the Cape of Good Hope. Concept Tested: Roaring Forties: strong Southern Hemisphere westerly winds in 40°–50°S latitudes; unobstructed by land

NDA 2008-I

Q. 24. The Westerlies are:

(a) Winds blowing from Subtropical High towards Sub-polar Low

(b) Winds blowing from Sub-polar Low towards Subtropical High

(c) Winds blowing from Tropical High towards Equatorial Low

(d) Winds blowing from Polar High towards Sub-polar Low

Answer: (a) Winds blowing from Subtropical High towards Sub-polar Low

Explanation: The Westerlies (or prevailing westerlies) are surface winds blowing from the subtropical high pressure belts (~30°N and 30°S) towards the sub-polar low pressure belts (~60°N and 60°S). Due to the Coriolis effect, they are deflected to the right in the Northern Hemisphere (blow from SW) and to the left in the Southern Hemisphere (blow from NW in reverse). The name “Westerlies” refers to their origin (they come FROM the west). The Westerlies in the Southern Hemisphere between 40°S and 60°S are the famous “Roaring Forties,” “Furious Fifties,” and “Screaming Sixties.” Concept Tested: Westerlies: blow from Subtropical High to Sub-polar Low; Coriolis deflects them; produce temperate weather systems

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