Q61 (CDS-I/2003) Geography › World Physical Geography › Atmospheric pressure winds Answer Verified

Assertion(A): Tropical cyclones do not develop very close to the Equator. Reason (R) : A weak coriolis effect retards the development of circular air motion.

Both A and R are individually true and R is the correct explanation of A

Both A and R are individually true but R is not the correct explanation of A

A is true but R is false

A is false but R is true

Result

Your answer: — · Correct: A

Explanation

Assertion (A) is true because tropical cyclones rarely form within 0° to 5° latitude of the Equator [3]. Reason (R) correctly explains this phenomenon: the Coriolis force is zero at the Equator and increases with latitude [2]. A strong Coriolis force is a necessary condition for cyclogenesis as it deflects inward-moving winds, creating the spiraling motion required for a cyclonic vortex [5]. Near the Equator, the weak or absent Coriolis effect prevents this rotation; instead, air flows directly into low-pressure areas, filling them rather than allowing them to intensify into organized storms [4]. Consequently, the lack of sufficient rotational force retards the development of circular air motion, making the Reason a valid explanation for the Assertion [3].

Sources

[3] INDIA PHYSICAL ENVIRONMENT, Geography Class XI (NCERT 2025 ed.) > Chapter 6: Natural Hazards and Disasters > Tropical Cyclone > p. 60
[1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 26: Tropical Cyclones > Coriolis Force > p. 356
[2] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 9: Atmospheric Circulation and Weather Systems > Coriolis Force > p. 79
[4] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 23: Pressure Systems and Wind System > Why Tropical Cyclones Do Not Form At The Equator? > p. 309
[5] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 23: Pressure Systems and Wind System > Why Tropical Cyclones Do Not Form At The Equator? > p. 310

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Assertion(A): Tropical cyclones do not develop very close to the Equator. Reason (R) : A weak coriolis effect retards the development of circular air motion.

Explanation

SIMILAR QUESTIONS

Assertion (A) : In temperate cyclones winds below from the periphery towards its centre. Reason (R) : There is high pressure in the centre of temperate cyclone.

Assertion (A) : The surface winds spiral inwards upon the centre of the cyclone. Reason (R) : Air descends in the centre of the cyclone.

Hurricanes rarely form or move within 5 degrees of the equator, because

In the South Atlantic and South-Eastern Pacific regions in tropical latitudes, cyclone does not originate. What is the reason?

Assertion (A): The salinity of oceans is relatively higher near the equator than at other regions. Reason (R): Equator region has heavy rainfall, high relative humidity and calm air.