Optics Question 765
Question: Velocity of light in glass whose refractive index with respect to air is 1.5 is $ 2\times 10^{8}m/s $ and in certain liquid the velocity of light found to be $ 2.5\times 10^{8}m/s $ . The refractive index of the liquid with respect to air is
[CPMT 1978; MP PET/PMT 1988]
Options:
A) 0.64
B) 0.80
C) 1.20
D) 1.44
Show Answer
Answer:
Correct Answer: C
Solution:
$ \mu \propto \frac{1}{v}\Rightarrow \frac{{\mu _{l}}}{{\mu _{g}}}=\frac{v _{g}}{v _{l}}\Rightarrow \frac{{\mu _{l}}}{1.5}=\frac{2\times 10^{8}}{2.5\times 10^{8}}\Rightarrow {\mu _{l}}=1.2 $
