question_answer

A fish looking up through the water sees the outside world, contained in a circular horizon. If the refractive index of water is 4/3 and the fish is 12 cm below the water surface, the radius of this circle (in cm) is     AIEEE  Solved  Paper-2005

A) \[36\sqrt{7}\]     

B)                        \[\frac{36}{\sqrt{7}}\]   

C)        \[36\sqrt{5}\]            

D)        \[4\sqrt{5}\]

Correct Answer: B

Solution :

                The situation is shown in figure. By Snell's law, where,is critical angle, or