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Physics · 2026 · 1 mark
CBSE 2026 · Region 1 · Set 2 · Q5
A concave lens of focal length 40 cm is coaxially in contact with two convex lenses, each of focal length 20 cm, on each side. The focal length of…
A concave lens of focal length $\displaystyle 40$ cm is coaxially in contact with two convex lenses, each of focal length $\displaystyle 20$ cm, on each side. The focal length of the combination is
Official answer
(D)
$\displaystyle \frac{40}{3} \mathrm{~cm}$
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CBSE Class 12 Physics past-paper question from the 2026 board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.