Optics Question 700
Question: If the focal length of a double convex lens for red light is $ f _{R}, $ its focal length for the violet light is
[EAMCET 2005]
Options:
A) $ f _{R} $
B) Greater than $ f _{R} $
C) Less than $ f _{R} $
D) $ 2f _{R} $
Show Answer
Answer:
Correct Answer: C
Solution:
$ f\propto \frac{1}{\mu -1} $ and $ \mu \propto \frac{1}{\lambda } $ .