Q 12-09-226JEE MainJEE Main 2025 (2 Apr, Shift 2)Easy
Two identical objects are placed in front of a convex mirror and a concave mirror having same radii of curvature of $12\ \text{cm}$, at the same distance of $18\ \text{cm}$ from the respective mirrors. The ratio of sizes of the images formed by the convex mirror and by the concave mirror is:
Answer: (A) $1/2$
$|f| = 6\ \text{cm}$, $u = -18\ \text{cm}$. For a mirror, $m = \dfrac{f}{f - u}$.
Convex ($f = +6$): $m_1 = \dfrac{6}{6 + 18} = \dfrac14$.
Concave ($f = -6$): $m_2 = \dfrac{-6}{-6 + 18} = -\dfrac12$.
$$\frac{|m_1|}{|m_2|} = \frac{1/4}{1/2} = \frac12$$
Solution by Sreeraj P, M.Sc Physics