Q. In order to obtain a real image of magnification 2 using a converging lens of focal length $20\ cm$, where should an object be placed
A) $50\ cm$
B) $30\ cm$
C) $- 50\ cm$
D) $- 30\ cm$
Explanation
(d) For real image $m = - 2$
$\therefore m = \frac{f}{u + f} \Rightarrow - 2 = \frac{f}{u + f} = \frac{20}{u + 20} \Rightarrow u = - 30\ cm$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.