Optics Question 756
Question: The ratio of thickness of plates of two transparent mediums A and B is 6 : 4. If light takes equal time in passing through them, then refractive index of B with respect to A will be
[UPSEAT 1999]
Options:
A) 1.4
B) 1.5
C) 1.75
D) 1.33
Show Answer
Answer:
Correct Answer: B
Solution:
Time taken by light to travel distance x through a medium of refractive index $ \mu $ is
$ t=\frac{\mu x}{c}\Rightarrow \frac{{\mu _{B}}}{{\mu _{A}}}=\frac{x _{A}}{x _{B}}=\frac{6}{4}\Rightarrow _{A}{\mu _{B}}=\frac{3}{2}=1.5 $
