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Answer the following. (Class 10 Science 2023, Q31)

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ScienceCBSE Class 10 · Board exam 2023, set 31/5/1 · 3 marks · Short answer

CBSE Class 10 Science 2023: question 31

Set in the CBSE Class 10 board exam of 2023, paper 31/5/1, section C, question 31, for 3 marks. Try it first; the hints and our step-by-step solution are below.

Q31 · 3 marks · Short answerThe Human Eye and the Colourful World

Answer the following.

  1. (a)

    State one important function of the following parts of the human eye : (i) Retina (ii) Pupil

    0 marks
  2. (b)

    State the role of ciliary muscles in focussing objects at varying distances from the eye.

    0 marks

Source: official question paper from cbse.gov.in (PDF). See it in the full 2023 board paper, set 31/5/1.

Hints

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

Hint 1

In a camera, which part does the job of the retina?

Hint 2

How does the eye cope with bright and dim light?

Hint 3

To see near objects the lens must become thicker. Which muscles do that?

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. (a)(i) Retina: it acts as a light-sensitive screen on which the image is formed. Its light-sensitive cells send signals to the brain through the optic nerve.

    1 mark

  2. (ii) Pupil: it regulates and controls the amount of light entering the eye. The iris adjusts its size.

    1 mark

  3. (b) Ciliary muscles relax or contract to change the curvature (thickness) of the eye lens, and hence its focal length. This lets the eye focus both near and distant objects on the retina (power of accommodation).

    1 mark

Answer: (a) Retina: light-sensitive screen where the image forms; Pupil: controls the amount of light entering the eye; (b) ciliary muscles change the curvature and so the focal length of the eye lens

Where the marks are

  • Function of retina (1 mark)
  • Function of pupil (1 mark)
  • Ciliary muscles change lens curvature and focal length to focus objects at different distances (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 31/5/1: 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.