Optics Question 445
Question: Critical angle of glass is $ {\theta _{1}} $ and that of water is $ {\theta _{2}} $ . The critical angle for water and glass surface would be $ ({\mu _{g}}=3/2,{\mu _{w}}=4/3) $
Options:
A) Less than $ {\theta _{2}} $
B) Between $ {\theta _{1}} $ and $ {\theta _{2}} $
C) Greater than $ {\theta _{2}} $
D) Less than $ {\theta _{1}} $
Show Answer
Answer:
Correct Answer: C
Solution:
[c] $ \sin {\theta _{1}}=\frac{1}{{\mu _{g}}} $
and $ \sin {\theta _{2}}=\frac{1}{{\mu _{w}}} $
Since $ {\mu _{g}}>{\mu _{w,}}{\theta _{1}}<{\theta _{2}} $
Critical angle $ \theta $ between glass and water will be given by $ \sin \theta =\frac{{\mu _{w}}}{{\mu _{g}}} $ Or $ \theta >{\theta _{2}} $
