I have seen the solution of this question but I did not und

Last updated: 6/26/2023

I have seen the solution of this question but I did not und erstand how and why have we used the concept of TIR her e How do we know that the angle is more than the critica angle and the angle of refraction is 90 6 A fish looking up through the water sees that the outside world is contained in a circular horizon if the refractive index of water is of the circle in centimeter is and the fish is 12 cm below the surface of water the radius