A plano convex lens is made of refractive index 1.6. The radius of curvature of the curved surface i

Question

A plano convex lens is made of refractive index 1.6. The radius of curvature of the curved surface is 60 cm . The focal length of the lens is\

Professor PC Thomas Classes · Answer

(b) : $R_{1}=+\infty, R_{2}=-60 \mathrm{~cm}$ 
$ \frac{1}{f}=(\mu-1)\left(\frac{1}{R_{1}}-\frac{1}{R_{2}}ight)=(1.6-1)\left(\frac{1}{\infty}-\frac{1}{-60}ight) $
 or $f=100 \mathrm{~cm}$\