Which of the following factors is/are responsible for the variations in insolation received at the surface of the Earth? 1. The angle of inclination of the sun’s rays 2. The transparency of the atmosphere 3. The configuration of land in terms of its aspect 4. The revolution of the Earth around the Sun has no influence on insolation variations Select the correct answer using the code given below:

Correct Option The correct option is 1, 2 and 3 only. Explanation Insolation (Incoming Solar Radiation) is the solar energy received by the Earth. The amount of insolation reaching the Earth's surface is not uniform; it varies spatially and temporally due to astronomical and geographical factors that influence the intensity and duration of sunlight. Statement-wise Analysis - Statement 1 is Correct: The angle of inclination of the sun’s rays determines the intensity of insolation. Vertical rays (high angle) cover a smaller surface area, resulting in higher energy concentration. Oblique rays (low angle) spread over a larger area, reducing energy intensity. Additionally, oblique rays traverse a thicker layer of the atmosphere, leading to greater absorption and scattering. - Statement 2 is Correct: The transparency of the atmosphere affects the transmission of solar radiation. Factors such as cloud cover, water vapor, and dust particles reflect, absorb, or scatter incoming solar radiation. For example, thick cloud cover significantly reduces the amount of insolation reaching the ground. - Statement 3 is Correct: The configuration of land, specifically its aspect (the direction a slope faces), influences insolation. In the Northern Hemisphere, south-facing slopes receive more direct sunlight and are warmer than north-facing slopes, which may remain in shadow or receive oblique rays. - Statement 4 is Incorrect: The revolution of the Earth around the Sun, combined with the tilt of the Earth's axis, is the primary cause of the seasons and the variation in the length of day and night. These variations directly influence the total amount of insolation received at different latitudes at different times of the year. Therefore, revolution does have a significant influence on insolation variations. Key Takeaway Key Takeaway: The primary factors affecting insolation at the Earth's surface include the rotation of the Earth, the angle of incidence of the sun’s rays, the duration of the day, the transparency of the atmosphere, and the configuration of the land (aspect). The Earth's revolution is a fundamental driver of seasonal insolation variations.

NCERT Class 11 Geography — Chapter 2: Solar radiation, heat balance and temperature

mcqeasy

Which of the following factors is/are responsible for the variations in insolation received at the surface of the Earth?

The angle of inclination of the sun’s rays
The transparency of the atmosphere
The configuration of land in terms of its aspect
The revolution of the Earth around the Sun has no influence on insolation variations

Select the correct answer using the code given below:

Official previous-year question

Verified 1 Aug 2026.

Options

A2, 3 and 4 only
B1, 2 and 3 only
C1 and 4 only
D1, 2, 3 and 4

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Solution

Correct Option

The correct option is 1, 2 and 3 only.

Explanation

Insolation (Incoming Solar Radiation) is the solar energy received by the Earth. The amount of insolation reaching the Earth's surface is not uniform; it varies spatially and temporally due to astronomical and geographical factors that influence the intensity and duration of sunlight.

Statement-wise Analysis

Statement 1 is Correct: The angle of inclination of the sun’s rays determines the intensity of insolation. Vertical rays (high angle) cover a smaller surface area, resulting in higher energy concentration. Oblique rays (low angle) spread over a larger area, reducing energy intensity. Additionally, oblique rays traverse a thicker layer of the atmosphere, leading to greater absorption and scattering.
Statement 2 is Correct: The transparency of the atmosphere affects the transmission of solar radiation. Factors such as cloud cover, water vapor, and dust particles reflect, absorb, or scatter incoming solar radiation. For example, thick cloud cover significantly reduces the amount of insolation reaching the ground.
Statement 3 is Correct: The configuration of land, specifically its aspect (the direction a slope faces), influences insolation. In the Northern Hemisphere, south-facing slopes receive more direct sunlight and are warmer than north-facing slopes, which may remain in shadow or receive oblique rays.
Statement 4 is Incorrect: The revolution of the Earth around the Sun, combined with the tilt of the Earth's axis, is the primary cause of the seasons and the variation in the length of day and night. These variations directly influence the total amount of insolation received at different latitudes at different times of the year. Therefore, revolution does have a significant influence on insolation variations.

Key Takeaway

Key Takeaway: The primary factors affecting insolation at the Earth's surface include the rotation of the Earth, the angle of incidence of the sun’s rays, the duration of the day, the transparency of the atmosphere, and the configuration of the land (aspect). The Earth's revolution is a fundamental driver of seasonal insolation variations.

Your note

More from Chapter 2: Solar radiation, heat balance and temperature

Which of the following best explains why the annual insolation received on 3rd January is slightly more than on 4th July?

easy

Consider the following data regarding the Heat Budget of the Earth: 1. 35 units are reflected back from the top of the clouds. 2. 14 units are absorbed within the atmosphere. 3. 51 units are absorbed by the earth’s surface. Which of the statements given above is/are correct?

hard

With reference to the heating of the atmosphere, consider the following statements: 1. Conduction is the process where heat is transferred through horizontal movement of air. 2. Convection is the process of vertical heating of the atmosphere. 3. Advection has no role in the diurnal variation of daily weather in middle latitudes. Which of the statements given above is/are correct?

medium

With reference to the variability of insolation at the surface of the Earth, consider the following statements: 1. The Earth receives slightly more annual insolation on 3rd January than on 4th July. 2. The variation in solar output due to the Earth's distance from the Sun has a drastic effect on daily weather changes. 3. The rotation of the Earth on its axis is one of the factors causing variations in insolation. Which of the statements given above is/are correct?

medium

Consider the following statements regarding the passage of solar radiation through the atmosphere: 1. The atmosphere is largely transparent to short wave solar radiation. 2. Water vapour and ozone in the troposphere are completely transparent to near infrared radiation. 3. The blue colour of the sky is a result of the absorption of light by water vapour. Which of the statements given above is/are correct?

medium

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Correct Option

The correct option is 1, 2 and 3 only.

Explanation

Statement-wise Analysis

Statement 1 is Correct: The angle of inclination of the sun’s rays determines the intensity of insolation. Vertical rays (high angle) cover a smaller surface area, resulting in higher energy concentration. Oblique rays (low angle) spread over a larger area, reducing energy intensity. Additionally, oblique rays traverse a thicker layer of the atmosphere, leading to greater absorption and scattering.
Statement 2 is Correct: The transparency of the atmosphere affects the transmission of solar radiation. Factors such as cloud cover, water vapor, and dust particles reflect, absorb, or scatter incoming solar radiation. For example, thick cloud cover significantly reduces the amount of insolation reaching the ground.
Statement 3 is Correct: The configuration of land, specifically its aspect (the direction a slope faces), influences insolation. In the Northern Hemisphere, south-facing slopes receive more direct sunlight and are warmer than north-facing slopes, which may remain in shadow or receive oblique rays.
Statement 4 is Incorrect: The revolution of the Earth around the Sun, combined with the tilt of the Earth's axis, is the primary cause of the seasons and the variation in the length of day and night. These variations directly influence the total amount of insolation received at different latitudes at different times of the year. Therefore, revolution does have a significant influence on insolation variations.