Physics · 2021
JEE Main · 17 March 2021, Shift 1 · Q13
The thickness at the centre of a plano convex lens is 3 mm and the diameter is 6 cm. If the speed of light in the material of the lens is 2 × 10^8…
The thickness at the centre of a plano convex lens is $\displaystyle 3$ mm and the diameter is $\displaystyle 6$ cm. If the speed of light in the material of the lens is $\displaystyle 2 \times 10^8 \mathrm{~ms}^{-1}$. The focal length of the lens is
\_\_\_\_.
Official answer
(1)
$\displaystyle 30$ cm
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JEE Main 2021 Physics question, with the answer from NTA’s final answer key. Where our answers come from.