Michigan Test for Teacher Certification (MTTC) Secondary Integrated Science Practice test

What is the phenomenon called that results in the bending of a wave when it passes through a boundary?

1. Refraction

2. Diffraction

3. Transmission

4. Reflection

The correct answer is: Diffraction

The phenomenon that results in the bending of a wave as it passes through a boundary is known as refraction. This occurs because waves travel at different speeds in different media. When a wave, such as light, moves from one medium to another—say, from air to water—its speed changes and causes the direction of the wave to change, resulting in bending. This change can be quantitatively described by Snell's Law, which relates the angles of incidence and refraction to the indices of refraction of the two media involved. In contrast, diffraction refers to the bending of waves around obstacles and the spreading out of waves when they pass through small openings. Transmission is the passing of waves through a medium without being absorbed or reflected, while reflection involves the bouncing back of a wave when it encounters a boundary. Each of these processes describes a different interaction of waves with their environments, but only refraction specifically pertains to the bending as waves transition between different media.