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

• A. 2
• B. 2.5
• C. 1.6
• D. 1.5

Answer 1

Answer: (D)

1.5

Answer 2

Let real depth of the bubble from one side is $x$. Then $\mu =\frac{x}{6}=\frac{15-x}{4}$ $\therefore x =9\, cm$ Hence, $\mu =\frac{x}{6}=\frac{9}{6}$ $=1.5$