Consider the following statements regarding the "Troposphere": 1. It contains dust particles. 2. It is devoid of water vapour. 3. It is the most important layer for biological activity. Which of the statements given above is/are correct?

The correct option is 1 and 3 only. Explanation The troposphere is the lowermost layer of the atmosphere, extending to an average height of 13 km (about 8 km at the poles and 18 km at the equator). It is the most significant layer regarding atmospheric mass, weather phenomena, and life support. - Statement 1 is correct: The troposphere contains the highest concentration of dust particles and aerosols. These solid particles are concentrated in the lower layers of the atmosphere and act as hygroscopic nuclei around which water vapour condenses to produce clouds and precipitation. - Statement 2 is incorrect: The troposphere is not devoid of water vapour. In fact, it contains approximately 99% of the atmosphere's total water vapour. The concentration of water vapour is highest near the surface and decreases rapidly with altitude. - Statement 3 is correct: This layer is the most important for biological activity. It contains the air necessary for respiration and is the site where all major weather phenomena (rainfall, fog, hailstorms, storms) occur, which directly influence the biosphere. Key Takeaway: The troposphere is the densest atmospheric layer, characterized by the presence of almost all water vapour, dust particles, and weather systems essential for life.

NCERT Class 11 Geography — Chapter 1: Composition and Structure of Atmosphere

mcqeasy

Consider the following statements regarding the "Troposphere":

It contains dust particles.
It is devoid of water vapour.
It is the most important layer for biological activity.

Which of the statements given above is/are correct?

Official previous-year question

Verified 1 Aug 2026.

Options

A1, 2 and 3
B2 only
C1 and 2 only
D1 and 3 only

Did you get this right?

Solution

The correct option is 1 and 3 only.

Explanation

The troposphere is the lowermost layer of the atmosphere, extending to an average height of 13 km (about 8 km at the poles and 18 km at the equator). It is the most significant layer regarding atmospheric mass, weather phenomena, and life support.

Statement 1 is correct: The troposphere contains the highest concentration of dust particles and aerosols. These solid particles are concentrated in the lower layers of the atmosphere and act as hygroscopic nuclei around which water vapour condenses to produce clouds and precipitation.
Statement 2 is incorrect: The troposphere is not devoid of water vapour. In fact, it contains approximately 99% of the atmosphere's total water vapour. The concentration of water vapour is highest near the surface and decreases rapidly with altitude.
Statement 3 is correct: This layer is the most important for biological activity. It contains the air necessary for respiration and is the site where all major weather phenomena (rainfall, fog, hailstorms, storms) occur, which directly influence the biosphere.

Key Takeaway: The troposphere is the densest atmospheric layer, characterized by the presence of almost all water vapour, dust particles, and weather systems essential for life.

Your note

More from Chapter 1: Composition and Structure of Atmosphere

Consider the following statements regarding the composition of the atmosphere: 1. The proportion of gases remains constant up to the highest layers of the atmosphere. 2. Nitrogen is the most abundant gas in the atmosphere. 3. Nitrogen and Oxygen make up the bulk of the atmosphere. Which of the statements given above is/are correct?

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Which of the following is the main reason for the rising volume of carbon dioxide in the atmosphere?

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Consider the following statements regarding water vapour in the atmosphere: 1. It is a variable gas that increases with altitude. 2. It accounts for less than one % of the air by volume in the dry and cold polar regions. 3. It absorbs parts of the insolation from the sun and preserves the earth’s radiated heat. Which of the statements given above is/are correct?

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With reference to the composition of the atmosphere, consider the following statements: 1. Oxygen is found in substantial quantities at heights above 120 km from the earth's surface. 2. Carbon dioxide is transparent to incoming solar radiation but opaque to outgoing terrestrial radiation. 3. Carbon dioxide and water vapour are found in uniform concentration up to the exosphere. Which of the statements given above is/are correct?

medium

Which one of the following is the most likely reason for the higher concentration of dust particles in subtropical and temperate regions compared to equatorial regions?

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The correct option is 1 and 3 only.

Explanation

Statement 1 is correct: The troposphere contains the highest concentration of dust particles and aerosols. These solid particles are concentrated in the lower layers of the atmosphere and act as hygroscopic nuclei around which water vapour condenses to produce clouds and precipitation.
Statement 2 is incorrect: The troposphere is not devoid of water vapour. In fact, it contains approximately 99% of the atmosphere's total water vapour. The concentration of water vapour is highest near the surface and decreases rapidly with altitude.
Statement 3 is correct: This layer is the most important for biological activity. It contains the air necessary for respiration and is the site where all major weather phenomena (rainfall, fog, hailstorms, storms) occur, which directly influence the biosphere.

Key Takeaway: The troposphere is the densest atmospheric layer, characterized by the presence of almost all water vapour, dust particles, and weather systems essential for life.