Q. The radius of curvature of convex surface of a thin plano-convex lens is 15 $cm$ and refractive index of its material is 1.6. The power of the lens will be
A) $+ 1\ D$
B) $- 2\ D$
C) $+ 3\ D$
D) $+ 4\ D$
Explanation
(d) $f = \frac{R}{(\mu - 1)} = \frac{15}{(1.6 - 1)} = 25\ cm$
$\therefore P = \frac{100}{f} = \frac{100}{25} = + 4D$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.