Question

A fish is located at a depth of 80cm in a pond. If refractive index of water is 1.33. Find the area of the surface of water through which it can see the outside world.

Answer 1

Given: Actual depth of bulb d1=0.8m

The refractive index of water is μ=1.33

Circle's radius, R=2AC

We know that,

μ=sinisin90∘

⇒i=48.75∘

Now, in the ΔOBC,

tan i=OBOC=d1R⇒R=0.91m

Area,

πR2=π×(0.91)2=2.61m2