Q. A plane convex lens is made of refractive index 1.6. The radius of curvature of the curved surface is $60\ cm$. The focal length of the lens is
A) $50\ cm$
B) $100\ cm$
C) $200\ cm$
D) $400\ cm$
Explanation
(b) $f = \frac{R}{(\mu - 1)} = \frac{60}{(1.6 - 1)} = 100\ cm$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.