Question

if the radius of curvature of the convex surface is 10cm and focal length of the lens 30 cm then the refractive index of a material of a plano convex lens is

Answer 1

Let $R_{1}\ and\ R_{2}$ are the radius of curvature of the convex surface and plane surface of the planoconvex lens.

As per the question $R_{1}=\ 10\ cm$

                                 $R_{2}=$ ∞

The focal length of the lens [f] = 30 cm.

From Lens maker's formula we know that-

                                  $\frac{1}{f} =[\mu -1][\frac{1}{R_{1}}- \frac{1}{R_{2}}]$

                                  $\frac{1}{30} =[\mu -1] [\frac{1}{10} -\frac{1}{\infty}]$

                                  $\frac{1}{30}=[\mu -1] \frac{1}{10}$

                                  $\frac{1}{3}= [\mu-1]$

                                  $\mu=\frac{1}{3} +1$

                                  $\mu =\frac{4}{3}$

Hence, the refractive index of the planoconvex lens is $\frac{4}{3}$

                                 

Answer 2

Answer:

IHOPE ANSWER IS CORRECT