What defines the angle created by a ray of light after refraction relative to the normal?

The angle created by a ray of light after it passes through a medium and is bent due to the change in its speed is known as the angle of refraction. This angle is measured from the normal line, which is an imaginary line perpendicular to the surface at the point of incidence where light enters a new medium.

The angle of incidence, on the other hand, refers to the angle formed by the incoming ray of light and the normal before the light refracts. The refraction index quantifies how much a medium can bend light, but it does not define the angle directly. Light divergence refers to the spreading of light rays from a point and is not relevant to the angles created during refraction.

Therefore, the angle of refraction is the correct choice as it specifically addresses the angle formed after the light has been refracted, providing a clear relationship to the normal at the boundary of the two media.