CBSE 2025 · Region 4 · Set 1 · Q10 · 1 mark
To get an image of magnification -$\displaystyle 1$ on a screen using a lens of focal length $\displaystyle 20$ cm , the object distance must be :
Official answer
From CBSE’s own marking scheme for this paper.
(C)
$\displaystyle 40$ cm
Light - Reflection and RefractionLens Formula and MagnificationApplymcqmedium
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CBSE Class 10 Science past-paper question from the 2025board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.