Total Internal Reflection
Suppose an interface XY separates a rarer medium (a) i.e; air from a denser medium (b) say water shown in fig. below. Explanation- " O" is a point object in the denser medium. A ray of light starting from "O" & incident normally along OA on XY passes straight along AB. Another ray incident along OA1 deviates away from normal and is refracted along A1B1. Clearly, angle of refraction is greater than the angle of incidence & if increase (talking about angle of refraction) with increase in angle of incidence; for a particular value of i=C, the critical angle, the incident ray OA2 is refracted at 90 degree & goes along interface, along A2B2. When i＞C as for the incident ray OA3, the ray goes along A3B3 as if it is reflected from interface XY. This phenomenon is called Total Internal Reflection. Thus we may define, total internal reflection is the phenomenon of reflection of light into a denser medium from an interface of this...
