Q 12-09-190JEE MainJEE Main 2020 (5 Sep, Shift 1)Medium
For a concave lens of focal length $f$, the relation between object and image distance $u$ and $v$, respectively, from its pole can best be represented by ($u = v$ is the reference line):
Answer: (A) Graph (A)
With magnitudes, $\dfrac1{|v|} = \dfrac1{|u|} + \dfrac1{|f|}$, so $|v| = \dfrac{|u||f|}{|u| + |f|}$.
Hence $|v| < |u|$ always (curve below the line $u = v$), $|v| \approx |u|$ for very small $u$ (tangent to $u = v$ at the origin), and $|v| \to |f|$ as $u \to \infty$, increasing steadily without overshooting. Graph (A) shows this.
Solution by Sreeraj P, M.Sc Physics