CBSE 2025 · Region 2 · Set 1 · Q12 · 1 mark
An object is placed at a distance of $\displaystyle 30$ cm from the pole of a concave mirror. If its real and inverted image is formed at $\displaystyle 60$ cm in front of the mirror, the focal length of the mirror is :
Official answer
From CBSE’s own marking scheme for this paper.
(B)
-$\displaystyle 20$ cm
Light - Reflection and RefractionSign Convention, Mirror 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.