Optics Question 734
Question: Refractive index of glass is $ \frac{3}{2} $ and refractive index of water is $ \frac{4}{3} $ . If the speed of light in glass is $ 2.00\times 10^{8} $ m/s, the speed in water will be
[MP PMT 1994; RPMT 1997]
Options:
A) $ 2.67\times 10^{8} $ m/s
B) $ 2.25\times 10^{8} $ m/s
C) $ 1.78\times 10^{8} $ m/s
D) $ 1.50\times 10^{8} $ m/s
Show Answer
Answer:
Correct Answer: B
Solution:
$ \mu \propto \frac{1}{v}\Rightarrow \frac{{\mu _{g}}}{{\mu _{w}}}=\frac{v _{w}}{v _{g}}\Rightarrow \frac{3/2}{4/3}=\frac{v _{w}}{2\times 10^{8}} $
$ \Rightarrow v _{w}=2.25\times 10^{8}m/s $
