Final answer:
The law of reflection states that for oblique incidence, the angle of incidence equals the angle of reflection relative to the normal, and both rays along with the normal lie in the same plane, leading to specular reflection from smooth surfaces and diffuse reflection from rough surfaces.
Step-by-step explanation:
Physical Principles of Reflection with Oblique Incidence
Reflection with oblique incidence involves two key physical principles:
The law of reflection, which states that the angle of incidence is equal to the angle of reflection (θ¹ = θ¹). These angles are measured relative to the normal, which is the line perpendicular to the surface where the light ray strikes.
Specular reflection where the incident and reflected rays, along with the normal, all lie in the same plane. This principle explains the predictable nature of reflection from smooth surfaces, which allows us to observe clear images in mirrors and use reflective devices in various applications.
On smooth surfaces like mirrors, this law results in a predictable reflection direction, enabling the creation of images and the usage of reflective optical instruments. In contrast, rough surfaces scatter light in many directions due to the variance in angles at each point of the surface, leading to diffuse reflection, which does not produce clear images but spreads light over larger areas.