With reference to the rainbow, consider the following statements: 1. It appears usually after rain when the Sun is low in the sky. 2. It is seen as a straight band of white light in the sky. 3. One can see a rainbow only when one's back is towards the Sun. Which of the statements given above is/are correct?

The correct option is (c). Explanation A rainbow is a natural spectrum produced by the dispersion of sunlight by tiny water droplets present in the atmosphere. This phenomenon results from a combination of refraction, dispersion, and internal reflection of light. Statement-wise Analysis: - Statement 1 is Correct: A rainbow is typically observed after rainfall when water droplets remain suspended in the atmosphere. For a rainbow to be visible to an observer on the ground, the Sun must be low in the sky (specifically, at an altitude of less than 42°). If the Sun is higher than this angle, the rainbow forms below the horizon and is not visible. - Statement 2 is Incorrect: A rainbow is not a straight band of white light. It appears as a circular arc (or a complete circle if viewed from a high altitude, such as an airplane). Furthermore, it is not white; it consists of a spectrum of colors (VIBGYOR) caused by the dispersion of white sunlight into its constituent wavelengths. - Statement 3 is Correct: The geometry of rainbow formation dictates that the observer must be positioned between the Sun and the rain. Sunlight enters the droplets from behind the observer, undergoes internal reflection within the droplets, and is directed back toward the observer's eyes. Therefore, one can only see a rainbow when one's back is towards the Sun. Key Takeaway: A rainbow is formed by the refraction, dispersion, and internal reflection of sunlight in water droplets and is visible only when the Sun is behind the observer and the water droplets are in front.

With reference to the rainbow, consider the… - NCERT Class 7 Science MCQ

NCERT Class 7 Science — Chapter 2: Light

mcqmedium

With reference to the rainbow, consider the following statements:

It appears usually after rain when the Sun is low in the sky.
It is seen as a straight band of white light in the sky.
One can see a rainbow only when one's back is towards the Sun.

Which of the statements given above is/are correct?

NCERT textbook question

From NCERT Science - class 7 · Page 135

Options

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

Did you get this right?

Solution

The correct option is (c).

Explanation

A rainbow is a natural spectrum produced by the dispersion of sunlight by tiny water droplets present in the atmosphere. This phenomenon results from a combination of refraction, dispersion, and internal reflection of light.

Statement-wise Analysis:

Statement 1 is Correct: A rainbow is typically observed after rainfall when water droplets remain suspended in the atmosphere. For a rainbow to be visible to an observer on the ground, the Sun must be low in the sky (specifically, at an altitude of less than 42°). If the Sun is higher than this angle, the rainbow forms below the horizon and is not visible.
Statement 2 is Incorrect: A rainbow is not a straight band of white light. It appears as a circular arc (or a complete circle if viewed from a high altitude, such as an airplane). Furthermore, it is not white; it consists of a spectrum of colors (VIBGYOR) caused by the dispersion of white sunlight into its constituent wavelengths.
Statement 3 is Correct: The geometry of rainbow formation dictates that the observer must be positioned between the Sun and the rain. Sunlight enters the droplets from behind the observer, undergoes internal reflection within the droplets, and is directed back toward the observer's eyes. Therefore, one can only see a rainbow when one's back is towards the Sun.

Key Takeaway: A rainbow is formed by the refraction, dispersion, and internal reflection of sunlight in water droplets and is visible only when the Sun is behind the observer and the water droplets are in front.

Your note

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