Optics Question 723
Question: If $ _{i}{\mu _{j}} $ represents refractive index when a light ray goes from medium i to medium j, then the product $ _{2}{\mu _{1}}\times _{3}{\mu _{2}}\times _{4}{\mu _{3}} $ is equal to
[CBSE PMT 1990]
Options:
A) $ _{3}{\mu _{1}} $
B) $ _{3}{\mu _{2}} $
C) $ \frac{1}{ _{1}{\mu _{4}}} $
D) $ _{4}{\mu _{2}} $
Show Answer
Answer:
Correct Answer: C
Solution:
$ _{2}{\mu _{1}}{\times _{3}}{\mu _{2}}{\times _{4}}{\mu _{3}}=\frac{{\mu _{1}}}{{\mu _{2}}}\times \frac{{\mu _{2}}}{{\mu _{3}}}\times \frac{{\mu _{3}}}{{\mu _{4}}}=\frac{{\mu _{1}}}{{\mu _{4}}}{= _{4}}{\mu _{1}}=\frac{1}{ _{1}{\mu _{4}}} $