What term describes the bending of a wave path when crossing into a medium with a different sound velocity?

What term describes the bending of a wave path when crossing into a medium with a different sound velocity?

• A. Refraction
• B. Incidence
• C. Rarefaction
• D. Reflection

Answer: (A)

Refraction is the bending of a wave path as it crosses into a medium with a different sound velocity. When the wave enters the new medium, its speed changes, and to keep the wavefronts continuous at the boundary, the direction shifts. For acoustics, this follows Snell’s law: sin(theta_in)/c1 = sin(theta_refracted)/c2. If the second medium is faster, the ray bends away from the normal; if slower, toward the normal. This bending explains why ultrasound alters its path at interfaces between materials. The other terms describe different phenomena: incidence is the arrival at the boundary, rarefaction is a low-pressure region of a longitudinal wave, and reflection is the wave bouncing back into the original medium.

Refraction is the bending of a wave path as it crosses into a medium with a different sound velocity. When the wave enters the new medium, its speed changes, and to keep the wavefronts continuous at the boundary, the direction shifts. For acoustics, this follows Snell’s law: sin(theta_in)/c1 = sin(theta_refracted)/c2. If the second medium is faster, the ray bends away from the normal; if slower, toward the normal. This bending explains why ultrasound alters its path at interfaces between materials. The other terms describe different phenomena: incidence is the arrival at the boundary, rarefaction is a low-pressure region of a longitudinal wave, and reflection is the wave bouncing back into the original medium.