Optics Question 617
Question: A plano convex lens is made of glass of refractive index 1.5. The radius of curvature of its convex surface is R. Its focal length is
[RPET 2003]
Options:
A) R/ 2
B) R
C) 2R
D) 1.5 R
Show Answer
Answer:
Correct Answer: C
Solution:
$ f=\frac{R}{(\mu -1)}=\frac{R}{(1.5-1)}=2R $