1. Tardigrade
  2. Question
  3. Physics
  4. The power of a biconvex lens is 10 dioptre and the radius of curvature of each surface is 10 cm. Then the refractive index of the material of the lens is,

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. The power of a biconvex lens is $10$ dioptre and the radius of curvature of each surface is $10\, cm$. Then the refractive index of the material of the lens is,

NEETNEET 2020Ray Optics and Optical Instruments

Solution:

$P=\frac{100}{f}$
$\Rightarrow f=\frac{100}{P}$
$=\frac{100}{10}=10\,cm$
$f=\frac{R}{2(\mu-1)}$ (for equiconvex lens)
$10=\frac{10}{2(\mu-1)}$
$(\mu-1)=\frac{1}{2}$
$\Rightarrow \mu=\frac{1}{2}+1$
$=\frac{3}{2}$