Critical Angle
The angle of incidence in denser medium for which the angle of refraction in the rarer medium is 90 degree, is called critical angle c of the medium.
Total internal Reflection
Total internal reflection is the optical phenomenon which is defined as the complete reflection of any light within denser medium such as glass or water after striking to the surface back into the medium. It is demonstrated by the figures below;



- Light must travel through denser medium
- Angle of incidence should be greater than the critical angle
Examples of Total Internal Reflection
- 1. Mirage
- 2. Brilliancy of Diamond
- 3. Optical fibers which use light for telecommunication
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