Question

What Is Critical Angle?

Answer 1

Critical Angle:

1. The critical angle is the angle of incidence to which the angle of refraction is equivalent to $90°$.
2. When light enters a denser media from such a comparably rarer medium, the orientation of light changes as well as the light beam bending towards the normal.
3. Absolute internal reflection is the complete reflection of such a light beam from the surrounding medium directly into a fluid medium as well as glasses.
4. This only happens whenever a light beam would be in a dense medium as well as approaches a much less dense media, whenever the light ray's angle of incidence is larger than the critical angle.

Therefore, it is the angle of incidence where the light refracts along the boundary between the two mediums.