Nonspecular reflection or scattering occurs when the interface is small. Which choice best matches this description?

• A. Specular reflection
• B. Nonspecular reflection or scattering
• C. Absorption
• D. Refraction

Answer: (B)

Light interaction at a boundary depends on how smooth the surface is at the scale of the light’s wavelength. When the interface is smooth enough, incident light reflects in a single direction, with the angle of incidence equal to the angle of reflection—this is specular reflection. If the boundary has small-scale roughness or irregularities, different tiny patches reflect light in different directions, so the reflected light spreads out instead of following a single mirror-like path. That diffuse or nonspecular reflection is what happens when the interface is small/rough relative to the wavelength. Absorption means the light energy is taken up by the material, not reflected, and refraction is the bending of light as it enters a medium with a different refractive index. So the description best matches nonspecular reflection or scattering.