Climate & Monsoon — Set 4

Correct Answer: B. Bay of Bengal

• **Bay of Bengal** = the primary moisture source for Meghalaya's heavy rainfall, as the SW monsoon's Bay branch is forced upward by the Khasi, Garo, and Jaintia hills. • **Garo, Khasi, Jaintia hills orographic lift** — these hills force Bay of Bengal moisture upward, creating the world-record rainfall at Cherrapunji and Mawsynram. • 💡 Wrong-option analysis: Indian Ocean: too general; Bay of Bengal is the specific moisture source; Arabian Sea: provides moisture to western India, not Meghalaya; Pacific Ocean: far away, no direct contribution to Indian rainfall.

Correct Answer: C. North-East to South-West

• **North-East to South-West** = the direction of winter monsoon winds in India, blowing from cold land toward the warm sea. • **North-East Trade Winds** — these dry winds blow from the cold Indian landmass to the sea, bringing rain only to Tamil Nadu after crossing the Bay of Bengal. • 💡 Wrong-option analysis: SW to NE: this is the summer monsoon direction; West to East: not the standard winter wind direction; South to North: opposite of actual winter wind direction.

Correct Answer: C. Tahiti and Darwin

• **Tahiti and Darwin** = the two locations between which the Southern Oscillation pressure seesaw occurs, linked to El Nino (ENSO). • **ENSO (El Nino Southern Oscillation)** — the combined phenomenon where Pacific ocean temperatures and atmospheric pressure changes interact to affect global weather. • 💡 Wrong-option analysis: Tokyo and Sydney: random cities, not the defined ENSO measurement points; Mumbai and Chennai: Indian cities, not the SO measurement locations; Delhi and Kolkata: Indian inland cities, irrelevant to Southern Oscillation.

Correct Answer: C. Bordoisila

• **Bordoisila** = the local Assamese name for violent pre-monsoon thunderstorms in spring, equivalent to West Bengal's Nor'westers/Kalbaisakhi. • **Spring season (March-April)** — the timing of Bordoisila storms that aid tea cultivation in Assam. • 💡 Wrong-option analysis: Mango Showers: Karnataka/Kerala phenomenon for mango ripening; Loo: hot dry winds of North India, not a storm; Kalbaisakhi: same type of storm but in West Bengal, not Assam.

Correct Answer: A. Punjab

• **Punjab** = the first state from which the monsoon begins to retreat, typically by early September, then moves southward over 2 months. • **Early September withdrawal** — the standard timing for the monsoon's first retreat from Punjab/Rajasthan in North India. • 💡 Wrong-option analysis: Odisha: on the eastern coast, monsoon retreats from here later; Tamil Nadu: last to see monsoon retreat because it gets NE monsoon rain; Kerala: one of the last states monsoon leaves, in late November.

Correct Answer: C. Due to the presence of the Indian Peninsula

• **Indian Peninsula's triangular shape** = divides the incoming SW Monsoon into the Arabian Sea branch (west coast) and Bay of Bengal branch (east/northeast). • **Two branches cover different zones** — Arabian Sea branch covers western India; Bay of Bengal branch covers eastern India and moves westward along Ganga plains. • 💡 Wrong-option analysis: Earth's rotation: affects the Coriolis force on winds but doesn't split monsoon into two named branches; Aravalli range: runs parallel to winds, doesn't split monsoon; High pressure over Tibet: affects monsoon intensity, not its division into two branches.

Correct Answer: B. Meghalaya

• **Meghalaya** = home to both Mawsynram (world's wettest) and Cherrapunji, both on the southern slopes of the Khasi Hills. • **Southern slopes of Khasi Hills** — the specific location that traps Bay of Bengal monsoon clouds, generating world-record rainfall. • 💡 Wrong-option analysis: Arunachal Pradesh: receives heavy rain but Cherrapunji/Mawsynram are not there; Assam: neighbour to Meghalaya, also very wet but not home to these places; Nagaland: northeastern state, not where these places are.

Correct Answer: C. October

• **October** = the transition month from the hot-rainy season to dry-winter conditions, when 'October Heat' phenomenon occurs. • **October Heat phenomenon** — the humid, hot weather in October as monsoon retreats but moisture lingers in the soil and atmosphere. • 💡 Wrong-option analysis: June: marks the onset of monsoon, transition from summer to rains; March: transition from winter to summer (pre-monsoon); December: deep winter, no monsoon transition.

Correct Answer: C. Wheat

• **Wheat** = Rabi crop that benefits most from Western Disturbance winter rain, which provides critical moisture during the growing phase. • **Punjab and Haryana** — the two states where Western Disturbance rain is most critical for high wheat yields. • 💡 Wrong-option analysis: Cotton: a Kharif crop needing SW monsoon summer rain; Jute: a Kharif crop needing abundant monsoon rain in eastern India; Rice: a Kharif crop needing SW monsoon rain, not winter rain.

Correct Answer: B. 100 to 120 days

• **100 to 120 days** = the average duration of the monsoon season in India, from early June to mid-September. • **June to mid-September** — the standard monsoon window, varying slightly across different parts of the country. • 💡 Wrong-option analysis: 150 to 180 days: too long for the monsoon season; 200 to 220 days: nearly seven months, greatly overestimates the duration; 50 to 80 days: too short; the monsoon typically lasts about four months.