Q. The magnifying power of a simple microscope is 6. The focal length of its lens in $metres$ will be, if least distance of distinct vision is $25\ cm$
A) $0.05$
B) $0.06$
C) $0.25$
D) $0.12$
Explanation
(a) $m = 1 + \frac{D}{f} \Rightarrow 6 = 1 + \frac{25}{f} \Rightarrow f = 5\ cm = 0.05\ m$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.