Which term describes the behavior when the surface is smooth and large relative to wavelength?

Which term describes the behavior when the surface is smooth and large relative to wavelength?

• A. Scattering
• B. Specular reflection
• C. Diffraction
• D. Refraction

Answer: (B)

When a surface is smooth and large relative to the wavelength, reflection is specular, like a mirror. The incident waves reflect in a single, well-defined direction because the surface behaves almost like a flat plane, so the angle of incidence equals the angle of reflection and the phase across the surface is nearly uniform. If the surface were rough on the scale of the wavelength, the reflected energy would scatter in many directions (diffuse reflection). Diffraction would occur when the size of an object or aperture is comparable to the wavelength, causing bending and spreading, and refraction involves bending as light enters a different medium due to a change in speed, not the surface smoothness. So the described behavior is specular reflection.

When a surface is smooth and large relative to the wavelength, reflection is specular, like a mirror. The incident waves reflect in a single, well-defined direction because the surface behaves almost like a flat plane, so the angle of incidence equals the angle of reflection and the phase across the surface is nearly uniform. If the surface were rough on the scale of the wavelength, the reflected energy would scatter in many directions (diffuse reflection). Diffraction would occur when the size of an object or aperture is comparable to the wavelength, causing bending and spreading, and refraction involves bending as light enters a different medium due to a change in speed, not the surface smoothness. So the described behavior is specular reflection.