What does the index of refraction directly measure? the angle between the incident ray and the normal line the angle between the refracted ray and the normal line the bending of light in a medium the reflection of light in a medium

The answer is The bending of light in a medium.

Explanation:

The refractive index is the dimensionless number that expresses the relationship between the speed of light in the air and the speed of light in the densest medium, that is, the refractive index directly measures the ratio of the velocity of the light in a vacuum and the speed of light in a medium. This phenomenon occurs because the light rays follow a rectilinear path, but when they pass from one means of transport to another, it is refracted, because the light has a velocity distance according to the density of the material it passes through. The refractive index has variables that affect the measurement, which are temperature, wavelength and pressure.

current flows in a wire

c. newton's third law of motion