NCERT Class 9 Geography — Chapter 1: Climate

mcqmedium

In the context of Indian climate, what is the significance of the 'Monsoon Trough'?

Official previous-year question

Verified 1 Aug 2026.

Options

AIt is a low-pressure area whose movement determines the spatial distribution of rainfall.
BIt is a wind system that brings winter rain.
CIt is a high-pressure belt that prevents rain.
DIt is a mountain range that blocks cold winds.

Did you get this right?

Solution

The correct option is

It is a low-pressure area whose movement determines the spatial distribution of rainfall.

Explanation

The Monsoon Trough is an elongated low-pressure area extending from the heat low over Pakistan to the head of the Bay of Bengal. It represents the northward shift of the Inter-Tropical Convergence Zone (ITCZ) over the Indian subcontinent during the summer monsoon season.

It is a high-pressure belt that prevents rain. is Incorrect: The Monsoon Trough is a region of intense low pressure, not high pressure. High-pressure systems generally inhibit cloud formation and rainfall, whereas this trough attracts moisture-laden winds.
It is a low-pressure area whose movement determines the spatial distribution of rainfall. is Correct: The position of the Monsoon Trough axis is dynamic. Its oscillation north and south determines the spatial distribution of rainfall:
- When the axis lies over the Gangetic plains, the region receives good rainfall (Active Phase).
- When the axis shifts closer to the Himalayas, rainfall ceases over the plains and increases in the foothills and Northeast India (Break Phase).
It is a wind system that brings winter rain. is Incorrect: The Monsoon Trough is associated with the Southwest Monsoon (summer rainfall), not winter rain. Winter rain in North India is typically caused by Western Disturbances.
It is a mountain range that blocks cold winds. is Incorrect: The Monsoon Trough is a meteorological phenomenon (an atmospheric pressure belt), not a physical landform or mountain range.

Key Takeaway: The periodic north-south oscillation of the Monsoon Trough axis is the primary factor governing the "active" and "break" periods of the Indian Summer Monsoon.

Your note

More from Chapter 1: Climate

Consider the following statements regarding the climatic conditions in India: 1. The climate of India is described as the 'Mediterranean' type. 2. There is a wide difference in day and night temperatures in the Thar Desert. 3. Coastal areas generally experience less contrast in temperature conditions compared to the interior. Which of the statements given above is/are correct?

medium

Which one of the following is the most likely reason for the wide difference between day and night temperatures in the Thar Desert compared to the Andaman and Nicobar Islands?

medium

With reference to the 'Climatic Controls', consider the following statements: 1. Air temperature generally increases from the equator towards the poles. 2. As one goes from the surface of the earth to higher altitudes, the atmosphere becomes less dense and temperature decreases. 3. Ocean currents have no influence on the climate of coastal areas. Which of the statements given above is/are correct?

medium

Consider the following statements regarding the factors affecting India's climate: 1. The Tropic of Cancer passes through the middle of the country. 2. The entire country lies in the tropical zone south of the Tropic of Cancer. 3. India's climate has characteristics of tropical as well as subtropical climates. Which of the statements given above is/are correct?

medium

Which of the following best explains why the Indian subcontinent experiences comparatively milder winters as compared to Central Asia?

easy

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The correct option is

It is a low-pressure area whose movement determines the spatial distribution of rainfall.

Explanation

It is a high-pressure belt that prevents rain. is Incorrect: The Monsoon Trough is a region of intense low pressure, not high pressure. High-pressure systems generally inhibit cloud formation and rainfall, whereas this trough attracts moisture-laden winds.
It is a low-pressure area whose movement determines the spatial distribution of rainfall. is Correct: The position of the Monsoon Trough axis is dynamic. Its oscillation north and south determines the spatial distribution of rainfall:
- When the axis lies over the Gangetic plains, the region receives good rainfall (Active Phase).
- When the axis shifts closer to the Himalayas, rainfall ceases over the plains and increases in the foothills and Northeast India (Break Phase).
It is a wind system that brings winter rain. is Incorrect: The Monsoon Trough is associated with the Southwest Monsoon (summer rainfall), not winter rain. Winter rain in North India is typically caused by Western Disturbances.
It is a mountain range that blocks cold winds. is Incorrect: The Monsoon Trough is a meteorological phenomenon (an atmospheric pressure belt), not a physical landform or mountain range.

Key Takeaway: The periodic north-south oscillation of the Monsoon Trough axis is the primary factor governing the "active" and "break" periods of the Indian Summer Monsoon.