1) Find the maximum refracting angle which a crown glass prism (1.52 refractive index) may have if sodium light is to pass through it with two refractions and no reflection? What deviation will be caused? 2) A beam of light strikes a water surface (refractive index 1.33) abd some of it is reflected by the surface and some is refracted. Find the angle of incidence of the beam of light if it is found that the refracted and the reflected rays are at right angle to each other. I have no idea what to do!! I tried limiting Theta 1 and 2 in Snell's law but no luck! Any help would be greatly recieved.