Find critical angle for water to air.

A fish in tank sees the outside world as if it is at the vertex of a cone such that the circular base of the cone is at the surface of the water.If the depth of the fish is d and the critical angle for water-air interface is C,what is the radius of circle?

What is the critical angle for materail of refractive index sqrt 2 ?

Find the criical angle for a raay of light going from paraffin oil to air .Given that the refractive index of paraffin oil with repsect to air is 1.44.

Refractive index of glass is 1.5 find critical angle for glass.

For glass-air interface,the critical angle is C.Will the critical angle for glass-water interface be greater or less than C?

Find the critical angle for a glass-water interface,if refractive index of glass 3//2 and that of water is 4//3 .

Define critical angle for total internal reflection.