Snell's law describes the physics of which phenomenon?

Snell's law describes the physics of which phenomenon?

• A. Reflection
• B. Refraction
• C. Scattering
• D. Absorption

Answer: (B)

Snell's law describes how a wave bends when it crosses a boundary between two media that have different propagation speeds. It ties the incident and refracted angles to the speeds (or refractive indices) of the two media, through the relationship n1 sin(theta1) = n2 sin(theta2). This means the beam will bend toward the normal when entering a slower medium and away from the normal when entering a faster medium, with the exact bend dictated by how much the speed changes. In ultrasound, this explains why beams change direction at tissue interfaces where speeds of sound differ, affecting the path and focusing of the image. The other phenomena aren’t about this boundary-driven bending: reflection is a bounce with the angle of incidence equal to the angle of reflection, while scattering and absorption involve deflection by particles or energy loss, not the refraction across a boundary.

Snell's law describes how a wave bends when it crosses a boundary between two media that have different propagation speeds. It ties the incident and refracted angles to the speeds (or refractive indices) of the two media, through the relationship n1 sin(theta1) = n2 sin(theta2). This means the beam will bend toward the normal when entering a slower medium and away from the normal when entering a faster medium, with the exact bend dictated by how much the speed changes. In ultrasound, this explains why beams change direction at tissue interfaces where speeds of sound differ, affecting the path and focusing of the image. The other phenomena aren’t about this boundary-driven bending: reflection is a bounce with the angle of incidence equal to the angle of reflection, while scattering and absorption involve deflection by particles or energy loss, not the refraction across a boundary.