American Board of Opticianry (ABO) Practice Test

What happens when rays of light go from a medium of less density to a more dense medium?

1. Minifies

2. Disperses

3. Reflects

4. Slows down

The correct answer is: Slows down

A This is incorrect because minification is a decrease in size or scope, which does not occur with light rays changing medium. B: This is incorrect because dispersion is the splitting of light into its component colors, not what happens when light changes medium. C: This is incorrect because reflection is when light bounces off a surface, which is not what occurs when light enters a different medium. D: This is correct because light slows down when it enters a more dense medium due to the increased interaction with particles in the medium. This can cause the light to change direction, depending on the angle of entry, which is known as refraction.