Optics Question 824
The given lens is broken into four parts and rearranged as shown. If the initial focal length is, then after rearrangement the equivalent focal length is-
Options:
f
f/2
f/4
4f
Show Answer
Answer:
Correct Answer: B
Solution:
Cutting a lens in transverse direction halves their focal length i.e. f/2.
Using the formula of equivalent focal length, $ \frac{1}{f}=\frac{1}{f _{1}}+\frac{1}{f _{2}}+\frac{1}{f _{3}}+\frac{1}{f _{4}} $
We get equivalent focal length at f/2.
BETA
