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What is scattering of light… (Class 10 Science 2023, Q24b)

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ScienceCBSE Class 10 · Board exam 2023, set 31/2/1 · 2 marks · Very short answer

CBSE Class 10 Science 2023: question 24(b)

Set in the CBSE Class 10 board exam of 2023, paper 31/2/1, section B, question 24(b), for 2 marks. Try it first; the hints and our step-by-step solution are below.

Q24(b) · 2 marks · Very short answerThe Human Eye and the Colourful World

What is scattering of light ? Why does the clear sky appear blue ?

Source: official question paper from cbse.gov.in (PDF). See it in the full 2023 board paper, set 31/2/1.

Hints

Open one hint at a time and try again before the next.

Hint 1

Think about what happens to a beam of light when it hits tiny particles in its path.

Hint 2

Compare the wavelengths of blue and red light. Which one is scattered more by very small particles?

Step-by-step solution

Each step shows the marks it earns, as an examiner would award them. Checked by an independent re-solve from the question paper.

  1. Scattering of light: When light strikes very small particles, such as molecules of air or fine dust and colloidal particles, its direction of travel changes and it spreads out in different directions. This change of direction is called scattering of light.

    1 mark

  2. Blue sky: Air molecules and other fine particles in the atmosphere are smaller than the wavelength of visible light. They scatter light of shorter wavelength (blue) much more strongly than light of longer wavelength (red). This scattered blue light enters our eyes from all directions, so the clear sky looks blue.

    1 mark

Answer: Scattering is the change in direction of light by small particles; the sky looks blue because fine air particles scatter blue (short wavelength) light more than red.

Where the marks are

  • Correct definition of scattering of light (1 mark)
  • Explains that fine particles scatter shorter-wavelength blue light more than red (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from The Human Eye and the Colourful World, one at a time, marked against the answer key and marking points.Back to the full paper2023 board paper, set 31/2/1: every question, by section.

The question is transcribed from the official paper; figures are described in words. The solution, hints and chapter tag are ours. Spotted an error? Write tosupport@questionbuddy.in.