Question

A fish looking upwards through the water seeing 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 surface,the radius of this circle in cm is

Answer 1

Using snell's law

sin(i) sin(r)=μ2 μ1

r=90° ;sin(r) =1 & μ2=1

sini=143=34

tani=3√7

; radius=36√7 better written as 36√77
Hope it will help you