Question

Total internal reflection is the complete reflection of a light ray _____.

Answer 1

B- Back into it's original medium.
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Answer 2

Answer: (B). Total internal reflection is the complete reflection of a light ray back into its original medium.

Explanation:

Reflection: The reflection will, when the incidence angle will make between $0^{\circ}$ and $90^{\circ}$.

In the reflection, the light ray moves one medium to another medium.

Total internal reflection: The total internal reflection will, when the incidence angle is greater than the critical angle.

In the total reflection, The light ray comes back into the original medium after reflection.

Critical angle: Critical angle permits the ray of light to be reflected back in the medium n₁ and it does not refract into the medium n₂.  

Hence, Total internal reflection is the complete reflection of a light ray back into its original medium.