Physics · 2025
JEE Main · 7 April 2025, Shift 1 · Q42
A lens having refractive index 1.6 has focal length of 12 cm, when it is in air. Find the focal length of the lens when it is placed in water. (Take…
A lens having refractive index $\displaystyle 1.6$ has focal length of $\displaystyle 12$ cm, when it is in air. Find the focal length of the lens when it is placed in water.
(Take refractive index of water as $\displaystyle 1.28$ )
Official answer
From NTA’s final answer key for this paper.
(2)
$\displaystyle 288$ mm
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JEE Main 2025 Physics question, with the answer from NTA’s final answer key. Where our answers come from.