The angle of reflection is:

The angle of reflection is:

• A. Equal to the angle of incidence
• B. Dependent on the couplant used
• C. Dependent on the frequency used
• D. Equal to the angle of refraction

Answer: (A)

The angle of reflection equals the angle of incidence. When a sound wave hits a smooth boundary, the reflected wave leaves at the same angle as the incoming wave, measured relative to the surface normal. This symmetry comes from how wavefronts behave at interfaces and holds in the ideal case regardless of the couplant or the frequency. The couplant affects how much energy is transmitted or reflected and how well the wave couples, but not the direction of the reflected beam. The angle of refraction describes the transmitted wave in the second medium, which follows Snell’s law and is a different concept from the reflected ray.

The angle of reflection equals the angle of incidence. When a sound wave hits a smooth boundary, the reflected wave leaves at the same angle as the incoming wave, measured relative to the surface normal. This symmetry comes from how wavefronts behave at interfaces and holds in the ideal case regardless of the couplant or the frequency. The couplant affects how much energy is transmitted or reflected and how well the wave couples, but not the direction of the reflected beam. The angle of refraction describes the transmitted wave in the second medium, which follows Snell’s law and is a different concept from the reflected ray.