Q. A double convex lens of glass of $\mu = 1.5$ has radius of curvature of each of its surface is $0.2$ $m$. The power of the lens is
A) $+ 10\ dioptres$
B) $- 10\ dioptres$
C) $- 5\ dioptres$
D) $+ 5\ dioptres$
Explanation
(d) $f = \frac{R}{2(\mu - 1)} \Rightarrow P = \frac{2(\mu - 1)}{0.2} = \frac{2(1.5 - 1)}{0.2} = + 5D$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.