Which phenomenon describes the bending of a wave as it passes from one medium into another with a different speed?

Which phenomenon describes the bending of a wave as it passes from one medium into another with a different speed?

• A. Attenuation
• B. Refraction
• C. Diffraction
• D. Scattering

Answer: (B)

Refraction is the bending of a wave as it crosses a boundary into a medium where its speed is different. When the wavefront hits the boundary at an angle, portions of the wave enter the second medium at different speeds, causing the direction of travel to change. This change in direction follows Snell’s law: the ratio of speeds (or the corresponding refractive indices) determines how much the path bends. If the second medium is slower, the refracted wave tilts toward the normal; if faster, it tilts away from the normal. A familiar example is light entering water from air, which slows down and bends toward the normal. Attenuation describes a decrease in amplitude, not bending. Diffraction is the bending of waves around obstacles or through openings. Scattering is the redirection of waves by irregularities or particles.

Refraction is the bending of a wave as it crosses a boundary into a medium where its speed is different. When the wavefront hits the boundary at an angle, portions of the wave enter the second medium at different speeds, causing the direction of travel to change. This change in direction follows Snell’s law: the ratio of speeds (or the corresponding refractive indices) determines how much the path bends. If the second medium is slower, the refracted wave tilts toward the normal; if faster, it tilts away from the normal. A familiar example is light entering water from air, which slows down and bends toward the normal.

Attenuation describes a decrease in amplitude, not bending. Diffraction is the bending of waves around obstacles or through openings. Scattering is the redirection of waves by irregularities or particles.