The condition required for total internal reflection to take place is:

1. light ray passes from a rarer to denser medium
2. light ray passes from a denser to rarer medium
3. angle of incidence is less than critical angle
4. none of the above

light ray passes from a denser to rarer medium

Reason — The two necessary conditions for total internal reflection are —

1. The light must travel from a denser medium to a rarer medium.
2. The angle of incidence must be greater than the critical angle for the pair of media.