Question

___ is an optical illusion observed in a hot region due to total internal reflection.

Answer 1

Mirage is an optical illusion observed in a hot region due to total internal reflection. As the land gets heated faster than the surrounding air, the atmosphere contains layers of air at different temperatures and thus different densities. The light coming from a distant object such as a tree undergoes multiple refractions due to the difference in optical densities of the layers. After a series of refractions, the incident angle becomes equal to the critical angle resulting in total internal reflection. The reflected light again undergoes multiple refractions. To an observer the rays appear to be coming from a point below the actual image, giving the perception of a mirror image formed in a water body.