CBSE 2026 · Region 3 · Set 2 · Q3 · 1 mark
An equiconvex lens of focal length $\displaystyle 15$ cm is cut into two equal plano-convex halves. The focal length of each half will be :(A)$\displaystyle 30$ cm(B)$\displaystyle 20$ cm(C)$\displaystyle 15$ cm(D)$\displaystyle 7 \cdot 5$ cm
An equiconvex lens of focal length $\displaystyle 15$ cm is cut into two equal plano-convex halves. The focal length of each half will be :
(A)
$\displaystyle 30$ cm
(B)
$\displaystyle 20$ cm
(C)
$\displaystyle 15$ cm
(D)
$\displaystyle 7 \cdot 5$ cm
Official answer
From CBSE’s own marking scheme for this paper.
(A)
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CBSE Class 12 Physics past-paper question from the 2026board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.