Optics Question 782
Question: A transparent cube of 15 cm edge contains a small air bubble. Its apparent depth when viewed through one face is 6 cm and when viewed through the opposite face is 4 cm. Then the refractive index of the material of the cube is
[CPMT 2004; MP PMT 2005]
Options:
A) 2.0
B) 2.5
C) 1.6
D) 1.5
Show Answer
Answer:
Correct Answer: D
Solution:
When viewed from face (1) $ \mu =\frac{u}{v}=\frac{x}{v} $
$ =\frac{x}{6} $ …..(i)
Now when viewed from face (2) $ \mu =\frac{15-x}{v}=\frac{15-x}{4} $ …..(ii)
From equation (i) and (ii) $ \mu =\frac{15-6\mu }{4} $
$ \Rightarrow \mu =1.5 $ .
