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For a concave mirror of focal… (Class 12 Physics 2023, Q9)

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PhysicsCBSE Class 12 · Board exam 2023, set 55/1/1 · 1 mark · MCQ

CBSE Class 12 Physics 2023: question 9

Set in the CBSE Class 12 board exam of 2023, paper 55/1/1, section A, question 9, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q9 · 1 mark · MCQRay Optics and Optical Instruments

For a concave mirror of focal length 'f', the minimum distance between the object and its real image is :

  1. (A)zero
  2. (B)f
  3. (C)2f
  4. (D)4f

Source: official question paper from cbse.gov.in (PDF). See it in the full 2023 board paper, set 55/1/1.

Hints

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

Hint 1

Where does the image form when the object is at C?

Hint 2

At C, the object and image coincide.

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. When the object is placed at the centre of curvature (2f), the real image is formed at the same point.

    ½ mark

  2. So the minimum distance between the object and its real image is zero. This is option (A).

    ½ mark

Answer: Zero, option (A)

Where the marks are

  • Object at C gives the image at C, so the distance is zero (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Ray Optics and Optical Instruments, one at a time, marked against the answer key and marking points.Back to the full paper2023 board paper, set 55/1/1: 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.