Physics · Geometrical Optics

JEE Main 2024 — 30 January, Shift 1 — Question 50

The distance between object and its two times magnified real image as produced by a convex lens is 45 cm . The focal length of the lens used is $\_\_\_\_\_\_$ cm .

Answer: 10

Numerical answer — enter this value.

Step-by-step solution

$\frac{v}{u}=-2$

$v=-2 u \ldots(\mathbf{( i )}$

$v-u=45$ $\Rightarrow u=-15 \mathrm{~cm}$

$v=30 \mathrm{~cm}$

$\frac{1}{f}=\frac{1}{v}-\frac{1}{u}$

$f=+10 \mathrm{~cm}$

Answer key and solution verified before publishing.

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Exam: JEE Main 2024
Paper: 30 January, Shift 1
Subject: Physics
Chapter: Geometrical Optics
Topic: Lenses and Their Combinations, Silvering of Lens