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QJEEM24Ph75c1: JEE Main 2024 Physics - Class 12 JEEM24Ph75c1 Solution: In an experiment to measure the focal length of a convex lens,…

In an experiment to measure the focal length (f)(f) of a convex lens, the magnitude of object distance (x)(x) and the image distance (y)(y) are measured with reference to the focal point of the lens. The yy - xx plot is shown in figure.

The focal length of the lens is ________ cm\mathrm{cm} .

JEE Main 2024 (Online) 30th January Evening Shift Physics - Geometrical Optics Question 34 English

Step-by-Step Verified Solution

amp;1f+20−1−(f+20)=1famp;2f+20=1ff=20 cm\begin{aligned}& \frac{1}{f+20}-\frac{1}{-(f+20)}=\frac{1}{f} \\& \frac{2}{f+20}=\frac{1}{f} \quad f=20 \mathrm{~cm}\end{aligned}

Or x1x2=f2\mathrm{x}_1 \mathrm{x}_2=\mathrm{f}^2 gives f=20 cm\mathrm{f}=20 \mathrm{~cm}

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