Optics Question 605
Question: Focal length of a convex lens will be maximum for
[MP PMT 1994]
Options:
A) Blue light
B) Yellow light
C) Green light
D) Red light
Show Answer
Answer:
Correct Answer: D
Solution:
$ f\propto \frac{1}{(\mu -1)} $ and $ \mu \propto \frac{1}{\lambda } $ . Hence $ f\propto \lambda $ and $ {\lambda _{r}}>{\lambda _{v}} $