Q. If the focal length of a double convex lens for red light is $f_{R},$ its focal length for the violet light is
A) $f_{R}$
B) Greater than $f_{R}$
C) Less than $f_{R}$
D) $2\ f_{R}$
Explanation
(c) $f \propto \frac{1}{\mu - 1}$ and $\mu \propto \frac{1}{\lambda}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.