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?

The correct option is 1 and 3 only. Explanation Insolation (Incoming Solar Radiation) is the solar energy received by the Earth's surface. The amount of insolation received at any specific point varies due to astronomical factors (Earth's orbit and rotation) and terrestrial factors (atmosphere and topography). Statement-wise Analysis: - Statement 1 is Correct: On January 3rd, the Earth is at Perihelion (closest to the Sun), and on July 4th, it is at Aphelion (farthest from the Sun). Consequently, the annual insolation received by the Earth on January 3rd is slightly more than the amount received on July 4th. - Statement 2 is Incorrect: Although there is a variation in solar output due to the changing distance between the Earth and the Sun, it does not have a drastic effect on daily weather changes. This variation is largely masked by other dominant factors such as the distribution of land and sea and atmospheric circulation. - Statement 3 is Correct: The rotation of the Earth on its axis is a primary factor causing variations in insolation. Rotation creates the cycle of day and night, determining the duration of exposure to sunlight, which directly influences the amount of energy received at the surface. Key Takeaway: While the Earth's distance from the Sun (Perihelion vs. Aphelion) causes a fluctuation in total solar energy received, its impact on surface weather is minimal compared to factors like the angle of incidence of sun rays, the length of the day, and atmospheric transparency.

With reference to the variability of… - NCERT Class 11 Geography MCQ

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

mcqmedium

With reference to the variability of insolation at the surface of the Earth, consider the following statements:

The Earth receives slightly more annual insolation on 3rd January than on 4th July.
The variation in solar output due to the Earth's distance from the Sun has a drastic effect on daily weather changes.
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?

NCERT textbook question

From NCERT Fundamentals of Physical Geography · Page 1

Options

A1, 2 and 3
B1 and 2 only
C2 only
D1 and 3 only

Did you get this right?

Solution

The correct option is 1 and 3 only.

Explanation

Insolation (Incoming Solar Radiation) is the solar energy received by the Earth's surface. The amount of insolation received at any specific point varies due to astronomical factors (Earth's orbit and rotation) and terrestrial factors (atmosphere and topography).

Statement-wise Analysis:

Statement 1 is Correct: On January 3rd, the Earth is at Perihelion (closest to the Sun), and on July 4th, it is at Aphelion (farthest from the Sun). Consequently, the annual insolation received by the Earth on January 3rd is slightly more than the amount received on July 4th.
Statement 2 is Incorrect: Although there is a variation in solar output due to the changing distance between the Earth and the Sun, it does not have a drastic effect on daily weather changes. This variation is largely masked by other dominant factors such as the distribution of land and sea and atmospheric circulation.
Statement 3 is Correct: The rotation of the Earth on its axis is a primary factor causing variations in insolation. Rotation creates the cycle of day and night, determining the duration of exposure to sunlight, which directly influences the amount of energy received at the surface.

Key Takeaway:
While the Earth's distance from the Sun (Perihelion vs. Aphelion) causes a fluctuation in total solar energy received, its impact on surface weather is minimal compared to factors like the angle of incidence of sun rays, the length of the day, and atmospheric transparency.

Your note

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

Consider the following statements regarding the insolation received at the Earth's surface: 1. Generally, at the same latitude, insolation is more over the continent than over the oceans. 2. In winter, the middle and higher latitudes receive more radiation than in summer. 3. The subtropical deserts receive more insolation than the equator. Which of the statements given above is/are correct?

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Which of the following is a characteristic of the isotherms in the Southern Hemisphere?

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With reference to the specific heat of land and water, consider the following statements: 1. The variation in temperature over the sea is much greater compared to land. 2. Land heats up and cools down more quickly than the sea. 3. Places near the sea experience extreme temperature variations. Which of the statements given above is/are correct?

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Which of the following is defined as "the energy needed to raise the temperature of one gram of substance by one Celsius"?

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In the context of the heat budget, what percentage of incoming solar radiation is reflected back to space before reaching the earth's surface?

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