Question

Total internal reflection can occur:

1,When a light ray strikes a surface parallel to the normal
2,When light moves into a material where it will travel with a slower speed
3,When the refracted ray bends toward the normal
4,When light travels from a material with higher refractive index into a material with lower refractive index

Answer 1

4.........................

Answer 2

Total internal reflection can occur : in option 4....