Question

A fish views outside from depth h inside water of refractive index n, then diameter of circle through which the outer objects become visible is??

Answer 1

After makig the figure U would get the final relation as
tanthetha = r/h
where thetha is the angle making with height h (perpendicular and the hypertenuse.)
and this angle is also the TIR angle.
Therfore from,
sinthetha = 1/u = ¾
thanthetha = 3/root(7)
and r = 36/root(7)

Answer 2

We know that in TIR CASE

Radius=H / whole root of n^2- 1

Were h is height and n is refractive index

But here we have to find diameter then in formula we have to write 2r

And then answer will be @( 2h/ whole root of n^2 -1 )@