Florida Teacher Certification Examinations (FTCE) Subject Area Practice Test

The bending of a wave when it enters a medium at a different speed is known as?

1. Diffraction

2. Reflection

3. Refraction

4. Dispersion

The correct answer is: Refraction

The bending of a wave when it transitions into a medium where its speed differs is known as refraction. This phenomenon occurs because waves travel at varying speeds in different materials, leading to changes in direction as the wavefronts enter a new medium at an angle. For instance, when light moves from air (a less dense medium) to water (a denser medium), it slows down and bends towards the normal line, which is an imaginary line perpendicular to the surface at the point of entry. This bending effect is important in various applications, such as lenses in optics and the behavior of waves as they travel from one medium to another, ensuring that the concept of refraction is fundamental to understanding wave behavior in physics. The other options involve different wave behaviors: diffraction pertains to the spreading of waves when they encounter obstacles or openings, reflection involves the bouncing back of waves when they hit a barrier, and dispersion refers to the separation of waves based on their frequencies, often seen in prisms when white light splits into its component colors. These concepts, while related to wave mechanics, do not describe the bending of waves as they enter a different medium.