CBSE 2026 · Region 4 · Set 1 · Q15 · 1 mark
Assertion (A) : When a convex lens made of glass is immersed in water, its converging power increases.
Reason (R) : The focal length of a lens depends only on the radii of curvature of its two faces.
Official answer
From CBSE’s own marking scheme for this paper.
(D)
Both Assertion (A) and Reason (R) are false.
Ray Optics and Optical InstrumentsRefraction at Spherical Surfaces and by LensesAnalyseassertion_reasonmedium
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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.