Which phenomenon occurs when a wave changes direction due to incidence with a boundary?

Which phenomenon occurs when a wave changes direction due to incidence with a boundary?

• A. Refraction
• B. Scattering
• C. Diffraction
• D. Specular reflection

Answer: (A)

Refraction is the bending of a wave’s path when it crosses into a different medium and its speed changes at the boundary. The change in speed as the wave enters the new medium causes the direction to bend, described by Snell’s law (n1 sin θ1 = n2 sin θ2). For example, light slows down when entering water from air and turns toward the normal; it speeds up and bends away from the normal when going from water back into air. This is different from specular reflection, where the wave bounces off the boundary without entering the other medium, or from scattering and diffraction, which involve spreading in various directions due to interactions with particles or obstacles. The scenario specifically involves crossing into another medium and changing direction because of that speed change, so refraction is the correct phenomenon.

Refraction is the bending of a wave’s path when it crosses into a different medium and its speed changes at the boundary. The change in speed as the wave enters the new medium causes the direction to bend, described by Snell’s law (n1 sin θ1 = n2 sin θ2). For example, light slows down when entering water from air and turns toward the normal; it speeds up and bends away from the normal when going from water back into air. This is different from specular reflection, where the wave bounces off the boundary without entering the other medium, or from scattering and diffraction, which involve spreading in various directions due to interactions with particles or obstacles. The scenario specifically involves crossing into another medium and changing direction because of that speed change, so refraction is the correct phenomenon.