What happens to refraction when the angle of incidence lies on the normal line?
When the angle of incidence lies on the normal line, refraction does not occur. This is because refraction is the bending of light as it passes from one medium to another, causing a change in direction. However, if the angle of incidence is such that it lies along the normal line (i.e., it is zero degrees), the light ray will simply continue traveling in a straight line without bending.
To understand this conceptually, it helps to know that the angle of incidence is measured relative to the normal line, which is perpendicular to the boundary between two different media. When the light ray approaches the boundary at a zero-degree angle, it is effectively parallel to the normal line. Since refraction occurs due to the change in speed of light across the boundary, when the angle of incidence is zero degrees, there is no change in speed or direction, leading to the absence of refraction.
To determine the behavior of light when the angle of incidence lies on the normal line, you can use Snell's law, which mathematically describes the relationship between the angles of incidence and refraction. Snell's law states that the ratio of the sines of the angles of incidence and refraction is equal to the ratio of the speeds of light in the two media. However, when the angle of incidence is zero degrees, the sine of the angle of incidence is also zero, making the equation meaningless in this specific case.
Therefore, when the angle of incidence lies on the normal line, refraction does not occur, and the light simply continues undisturbed along its original path.