Question

What is meant by total internal reflection ? Explain with a neat diagram and write

any two applications of total internal reflection.
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Answer 1

Answer:

In general, total internal reflection takes place at the boundary between two transparent media when a ray of light in a medium of higher index of refraction approaches the other medium at an angle of incidence greater than the critical angle. For a water-air surface the critical angle is 48.5°. Because indices of refraction depend on wavelength, the critical angle (and hence the angle of total internal reflection) will vary slightly with wavelength and, therefore, with colour. At all angles less than the critical angle, both refraction and reflection occur in varying proportions.

Answer 2

Answer:

The word "total" in "total internal reflection" is used in the following sense: all of the light that could possibly propagate away from this surface is reflected, and none is refracted.

1. fibre broadband internet sends computer information coded as pulses of light along underground optical fibres;
2. doctors can look at the inside of their patients using an endoscope - a long tube which guides light into the patient and then guides the reflected light back out to give an image;