Q. The sun’s diameter is $1.4 \times 10^{9}m$ and its distance from the earth is $10^{11}m$. The diameter of its image, formed by a convex lens of focal length $2m$ will be
A) $0.7\ cm$
B) $1.4\ cm$
C) $2.8\ cm$
D) Zero ($i.e.$ point image)
Explanation
(c) $\theta = \frac{AB}{10^{11}} = \frac{A^{'}B'}{2} \Rightarrow A^{'}B^{'} = \frac{2 \times 1.4 \times 10^{9}}{10^{11}} = 2.8\ cm$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.