Question

The focal length of a plane convex glass lens is 50 cm. Find the radius of curvature of its curved surface ($\mu$ of glass$=1.5$)

Answer 1

Given,

$\mu =1.5$

$f=+50cm$

From lens maker formula

$\frac{1}{f}=(\mu -1)(\frac{1}{R_1}-\frac{1}{R_2})$

$\frac{1}{50cm}=(1.5-1)(\frac{1}{R}-\frac{1}{-R})=\frac{2\times 0.5}{R}$

$R=2\times 0.5\times 50=50cm$

The radius of curvature is $50cm.$