Question

a ray of light is incident at 60° on glass air interface .what will be the light ray ?

Answer 1

The light ray will undergo refraction (the ray will divert from its path).
Here if the light travels from glass to air , the light may get reflected back to the glass when the angle of incidence is greater than the critical angle.

The critical angle can be found out in this case by taking refractive index of glass = 1.5
Then critical angle c is given by

sin c = (1/refractive index of glass)
sin c= (1/ 1.5)
Then c=41.1 °

Since 60° is larger than this angle, the light ray gets reflected back .