Ohio Assessment for Educators (OAE) Integrated Science (024) Practice Exam

According to Snell's Law, what happens to the speed of light in a medium when the angle of incidence is smaller?

1. The speed of light decreases

2. The speed of light becomes infinite

3. The speed of light increases

4. The speed of light remains constant

The correct answer is: The speed of light increases

According to Snell's Law, the relationship between the angles of incidence and refraction when light passes from one medium to another is directly tied to the speeds of light in those media. When the angle of incidence decreases, it means the light is entering the medium more directly, which typically can lead to an increase in the speed of light within the medium if transitioning from a less optically dense material to a more optically dense one. In simpler terms, as the angle of incidence becomes smaller, the refraction effect—the bending of light—becomes less pronounced. In this scenario, light generally travels faster in the medium compared to scenarios where the angle of incidence is greater. Therefore, the correct answer points out that the speed of light increases as the angle of incidence decreases, aligning with the principles of wave behavior and the changes in light's velocity in different media described by Snell's Law.