Question

explain total internal reflection in case of optical fiber with neat sketch.​

Answer 1

Answer:

When an oblique ray of light travels from optically denser medium to an optically rarer medium, it bends away from the normal at the surface separating the two media.

Explanation:

∙ According to Snells law, the angle of refraction increases with the increase in the angle of incidence. The figure below shows refraction between two media.

∙ As shown in the figure above, the rays AB2​ and AB3​ originating from Point A of the source undergoes partial refraction and partial reflection.

∙ The refracted ray for the incident ray AB4​ travels along the surface separating the two media. So, its angle of refraction is 90∘.

∙ When a ray of light travels from the denser medium to the rarer medium, the angle of incidence for which the angle of refraction is 90∘ is known as the critical angle.

∙ When the angle of incidence exceeds the critical angle, the ray is totally internally reflected. This is the phenomenon of total internal reflection.

Hope you understand.

For better understanding look at the diagram given below.