UPSC CIVIL SERVICES EXAMINATION

PRELIMS SPECIAL

1995 - 2018

PREVIOUS YEAR QUESTIONS

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Climatology

(Humidity & Cyclones)

CHAPTER LISTING

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Unit Chapter

World Geography

Physical Geography

Geomorphology

Climatology

Oceanography

Biogeography

Social Geography

Economic Geography

Indian Geography

Physical Geography

Basics of India

Physical features

River systems

Climate

Agriculture

Vegetation and Fauna

Social Geography

Economic Geography

L4-L5

L1 – L3

CHAPTER LISTING

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L4

Chapter Topics

Climatology

Atmosphere

Temperaure & Insolation

Pressure Belts & Wind Systems

Humidity & Precipitation

Cyclones & Anti Cyclones

Major Climatic Types

L 5

Q 54-60

Q. Consider the following climatic and geographical phenomena: [2002]

1. Condensation

2. High temperature and humidity

3. Orography

4. Vertical wind

Thunder cloud development is due to which of these phenomena?

(a) 1 and 2

(b) 2, 3 and 4

(c) 1, 3 and 4

(d) 1, 2 , 3 and 4

QUESTION 54

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QUESTION 54

• The transformation of water vapour into water iscalled condensation.

• Condensation is caused by the loss of heat (latent heat ofcondensation, opposite of latent heat of vaporization).

• When moist air is cooled, it may reach a level when its capacityto hold water vapour ceases (Saturation Point = 100% RelativeHumidity = Dew Point reached). Then, the excess water vapourcondenses into liquid form.

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Condensation

• As air rises upwards, it expands as a result of fall in pressure. Thisexpansion causes air to cool.

• A dry air mass rising upwards cools at a rate of 10o C per 1000metres.

• If the air mass is moist, then it cools at a rate of about 5o C per1000 metres because the latent heat of vaporisation released bywater vapours slows down the cooling rate.

Adiabatic rate of cooling

Q. Consider the following climatic and geographical phenomena: [2002]

1. Condensation

2. High temperature and humidity

3. Orography

4. Vertical wind

Thunder cloud development is due to which of these phenomena?

(a) 1 and 2

(b) 2, 3 and 4

(c) 1, 3 and 4

(d) 1, 2 , 3 and 4

Answer: d

QUESTION 54

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Q. Assertion (A) : The surface winds spiral inwards upon the centre of the cyclone.

Reason (R) : Air descends in the centre of the cyclone.

In the context of the above two statements, which one of the following is correct?[2002]

(a) Both A and R are true and R is the correct explanation of A

(b) Both A and R are true but R is NOT a correct explanation of A

(c) A is true but R is false

(d) A is false but R is true

QUESTION 55

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QUESTION 55

• Low pressure systems surrounded by regions with relativelyhigher pressure.

• Are of two types Tropical Cyclones Extra Tropical Cyclones or Temperate cyclones

• Cyclones are strong weather systems and bring heavy rainfalland high velocity winds.

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Cyclones

Tropical Cyclone

• Tropical cyclones are violent storms that originate over oceansin tropical areas

• The low pressure at the center is responsible for the windspeeds.

• The cyclonic wind movements are anti-clockwise in the northernhemisphere and clockwise in the southern hemisphere (This isdue to Coriolis force).

Tropical Cyclones

QUESTION 55

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Tropical Cyclone

QUESTION 55

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Tropical Cyclone Prone Regions

QUESTION 55

• Dry air subsides at the centre of the cyclone inducing calm weather at the centre of the storm.• Surface winds spiral inwards upon the centre as a result of low pressure at the centre.

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Q. Assertion (A) : The surface winds spiral inwards upon the centre of the cyclone.

Reason (R) : Air descends in the centre of the cyclone.

In the context of the above two statements, which one of the following is correct?[2002]

(a) Both A and R are true and R is the correct explanation of A

(b) Both A and R are true but R is NOT a correct explanation of A

(c) A is true but R is false

(d) A is false but R is true

Answer: b

QUESTION 55

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Q.

(a) A

(b) B

(c) C

(d) D

QUESTION 56

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Which one of the areas marked as A, B, C and D in the given

figure of the cyclone, witnesses heavy torrential short

duration rainfall accompanied by thunderstorms? [1999]

QUESTION 56

Low pressure systems formed in temperateregions due to interaction of cold (polareasterlies) and warm (westerlies) air massesand front formation.

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Temperate cyclones

• Front is a three dimensional boundaryzone formed between two converging airmasses with different physicalproperties (temperature, humidity,density etc.).

• The process of formation of a front isknown as Frontogenesis, and dissipationof a front is known as Frontolysis.

Fronts

QUESTION 56

• The wind motion on both sides of the frontis parallel to the front.

• Cumulonimbus clouds are formed.Overrunning of warm air along such a frontcauses frontal precipitation.

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Stationary Front

• When a cold air mass replaces a warm airmass by advancing into it.

• Cold front moves up to twice as quickly aswarm fronts. Frontolysis begins when thewarm air mass is completely uplifted by thecold air mass.

• Severe storms can occur. During the summermonths thunderstorms are common.

Cold Front

QUESTION 56

• Frontal surface along whichactive movement of warm airover cold air takes place.

• Such fronts cause moderate togentle precipitation over alarge area, over several hours.

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Warm Front

• A process by which the coldfront of a rotating low-pressuresystem catches up the warmfront, so that the warm airbetween them is forcedupwards.

Occluded Front

QUESTION 56

Low pressure systems formed in temperateregions due to interaction of cold (polareasterlies) and warm (westerlies) air massesand front formation.

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Temperate cyclones

• Front is a three dimensional boundaryzone formed between two converging airmasses with different physicalproperties (temperature, humidity,density etc.).

• The process of formation of a front isknown as Frontogenesis, and dissipationof a front is known as Frontolysis.

Fronts

Q.

(a) A

(b) B

(c) C

(d) D

Answer: d

QUESTION 56

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Which one of the areas marked as A, B, C and D in the given

figure of the cyclone, witnesses heavy torrential short

duration rainfall accompanied by thunderstorms? [1999]

Q. Willy is : [1995]

(a) a type of tree grown in temperate regions

(b) a wind that blows in a desert

(c) a tropical cyclone of the north-west Australia

(d) a kind of common fish found near Laccadives Islands

QUESTION 57

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QUESTION 57

• Known by different names in differentnames in different parts of the world: West Pacific: Typhoon Atlantic Ocean: Hurricane Indian Ocean: Cyclone Western Australia: Willy

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Tropical Cyclones

Q. Willy is : [1995]

(a) a type of tree grown in temperate regions

(b) a wind that blows in a desert

(c) a tropical cyclone of the north-west Australia

(d) a kind of common fish found near Laccadives Islands

Answer: c

QUESTION 57

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Q. Sun's halo is produced by the refraction of light in: [2002]

(a) water vapour in Stratus clouds

(b) ice crystals in Cirro-Cumulus clouds

(c) ice crystals in Cirrus clouds

(d) dust particles in Stratus clouds

QUESTION 58

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QUESTION 58

Cloud is a mass of minute water droplets or tinycrystals of ice formed by the condensation of thewater vapour in free air at considerable elevations.

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Clouds

• Cirrus: Formed at higher altitudes ( 8 – 12 km);Thin, white in color, composed of ice crystals &gives feathery appearance.

• Cumulus: Looks like a cotton wool, have flat base;Exist in patches, formed at 4-7 km

• Stratus: Occurs in form of sheet of layers,covering almost all the sky; Generally formed dueto loss of heat or mixing of air masses at differenttemp.

• Nimbus: Black & grey color clouds, formed nearearth surface; Extremely dense & opaque to sunrays

Types of Clouds

QUESTION 57

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Q. Sun's halo is produced by the refraction of light in: [2002]

(a) water vapour in Stratus clouds

(b) ice crystals in Cirro-Cumulus clouds

(c) ice crystals in Cirrus clouds

(d) dust particles in Stratus clouds

Answer: c

QUESTION 58

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Q. For short-term climatic predictions, which one of the following events, detected in the last

decade, is associated with occasional weak monsoon rains in the Indian sub-continent? [2002]

(a) La Nina

(b) Movement of Jet Stream

(c) El Nino. and Southern Oscillations

(d) Greenhouse effect at global level

QUESTION 59

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QUESTION 59

El Niño is the name given to occasional development of warm ocean surface waters along the coast of Ecuador& Peru.

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El NIno

QUESTION 59

• El Nino and Indian monsoon are inversely related.• The most prominent droughts in India – six of them – since 1871 have been El Nino droughts, including the

recent ones in 2002 and 2009.• El Nino directly impacts India’s agrarian economy as it tends to lower the production of summer crops such as

rice, sugarcane, cotton and oilseeds.• The ultimate impact is seen in the form of high inflation and low gross domestic product growth as

agriculture contributes around 14 per cent to the Indian economy.

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El Nino & Monsoon

• This phenomenon is just the opposite of El Niño. In some years, the trade winds can become extremelystrong and an abnormal accumulation of cold water can occur in the central and eastern Pacific. This eventis called a La Niña.

• La Niña results in abnormally heavy monsoons in India and SE Asia, wet winter in Eastern Africa & Australia,and drought in southern United States & South America.

La Nina

Q. For short-term climatic predictions, which one of the following events, detected in the last

decade, is associated with occasional weak monsoon rains in the Indian sub-continent? [2002]

(a) La Nina

(b) Movement of Jet Stream

(c) El Nino. and Southern Oscillations

(d) Greenhouse effect at global level

Answer: c

QUESTION 59

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Q. In the South Atlantic and South-Eastern Pacific regions in tropical latitudes, cyclone does

not originate. What is the reason? [2015 - I]

(a) Sea surface temperatures are low

(b) Inter-Tropical Convergence Zone seldom occurs

(c) Coriolis force is too weak

(d) Absence of land in those regions

QUESTION 60

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QUESTION 59

• Sea surface temperatures are low.• Very high wind shear• Presence of cold ocean currents.

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Why no tropical cyclones in South Atlantic and South eastern Pacific ?

Q. In the South Atlantic and South-Eastern Pacific regions in tropical latitudes, cyclone does

not originate. What is the reason? [2015 - I]

(a) Sea surface temperatures are low

(b) Inter-Tropical Convergence Zone seldom occurs

(c) Coriolis force is too weak

(d) Absence of land in those regions

Answer: a

QUESTION 60

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