Student Login

Home›Chapters›Ray Optics PYQs›Spherical Surfaces & Thin Lenses›Question 94

JEE Main 2019 (10 Apr, Shift 2) · Spherical Surfaces & Thin Lenses

Spherical Surfaces & Thin Lenses question from JEE Main 2019 (10 Apr, Shift 2)

Q94JEE Main 2019 · 10 APR · SHIFT 2Medium

Spherical Surfaces & Thin Lenses

The graph shows how the magnification m produced by a thin lens varies with image distance v. What is the focal length of the lens used?

Show answer and solution

Answer: (d)

For a lens $m = \frac{f - v}{f}$ , so $|m|$ varies linearly with $v$ with slope $\frac{1}{f}$ .
From the graph, slope $= \frac{c}{b}$ .
$\frac{1}{f} = \frac{c}{b} \Rightarrow f = \frac{b}{c}$
So the answer is (d) $\frac{b}{c}$ .

Report a mistake

More questions on Spherical Surfaces & Thin Lenses

The refractive index of the material of a concave lens is μ. It is immersed in a medium…JEE Main 2014 (12 Apr, Shift 1)
A thin convex lens made from crown glass (μ = 3/2) has focal length f. When it is…JEE Main 2014
An object is located in a fixed position in front of a screen, Sharp image is obtained on…JEE Main 2014 (11 Apr, Shift 1)
Diameter of a plano-convex lens is 6 cm and thickness at the center is 3 mm. If speed of…JEE Main 2013
The image of an illuminated square is obtained on a screen with the help of a converging…JEE Main 2013 (22 Apr, Shift 1)
When a biconvex lens of glass having refractive index 1.47 is dipped in a liquid, it acts…NEET 2012 (AIPMT, Prelims)
A converging beam of rays is incident on a diverging lens. Having passed through the lens…NEET 2011 (AIPMT, Mains)
A biconvex lens has a radius of curvature of magnitude 20 cm. Which one of the following…NEET 2011 (AIPMT, Prelims)