Optics Question 824
Question: The given lens is broken into A four parts and rearranged as shown. If the initial focal length is/then after rearrangement the equivalent focal length is-
Options:
A) f
B) f/2
C) f/4
D) 4f
Show Answer
Answer:
Correct Answer: B
Solution:
[b] Cutting a lens in transverse direction doubles their focal length i.e. 2f.
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 as f/2.
