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An object is placed at a… (Class 10 Science 2024, Q24)

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ScienceCBSE Class 10 · Board exam 2024, set 31/1/1 · 2 marks · Very short answer

CBSE Class 10 Science 2024: question 24

Set in the CBSE Class 10 board exam of 2024, paper 31/1/1, section B, question 24, for 2 marks. Try it first; the hints and our step-by-step solution are below.

Q24 · 2 marks · Very short answerLight – Reflection and Refraction

An object is placed at a distance of 10 cm from a convex mirror of focal length 15 cm. Find the position of the image formed by the mirror.

Source: official question paper from cbse.gov.in (PDF). See it in the full 2024 board paper, set 31/1/1.

Hints

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

Hint 1

Use the New Cartesian sign convention: an object in front means u is negative; a convex mirror has positive f.

Hint 2

Apply and interpret the sign of v.

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. Given cm and cm (convex mirror). Mirror formula: .

    ½ mark

  2. ½ mark

  3. cm. The image is formed 6 cm behind the mirror; it is virtual and erect.

    1 mark

Answer: v = +6 cm, i.e. 6 cm behind the mirror (virtual, erect)

Where the marks are

  • Correct sign convention and mirror formula (½ mark)
  • Correct substitution (½ mark)
  • v = +6 cm, behind the mirror (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Light – Reflection and Refraction, one at a time, marked against the answer key and marking points.Back to the full paper2024 board paper, set 31/1/1: 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.