Optics Question 87
Question: A diverging beam of light from a point source S having divergence angle a, falls symmetrically on a glass slab as shown. The angles of incidence of the two extreme rays are equal. If the thickness of the glass slab is t and the refractive index n, then the divergence angle of the emergent beam is
[IIT-JEE (Screening) 2000]
Options:
A) Zero
B) a
C) $ {{\sin }^{-1}}(1/n) $
D) $ 2{{\sin }^{-1}}(1/n) $
Show Answer
Answer:
Correct Answer: B
Solution:
Since rays after passing through the glass slab just suffer lateral displacement hence we have angle between the emergent rays asa.
