Question

The reflection of light from a smooth surface is called
(a) diffused reflection
(b) regular reflection
(c) dispersion
(d) spectrum

Answer 1

Answer:

(b) regular reflection

Answer 2

Explanation:

Diffuse reflection is the reflection of light from a surface such that an incident ray is reflected at many angles, rather than at just one angle as in the case of specular reflection. An illuminated ideal diffuse reflecting surface will have equal luminance from all directions in the hemisphere surrounding the surface, i.e. Lambertian reflectance. A surface built from a non-absorbing powder such as plaster, or from fibres such as paper, or from a polycrystalline material such as white marble, reflects light diffusely with great efficiency. Many common materials exhibit a mixture of specular and diffuse reflection.

When a beam of light falls at a particular angle onto a very smooth opaque surface, almost the whole light will be reflected from the interface along a narrow set of directions. The surface would be judged as very glossy as shown in Fig. 2.2a. At certain viewing angles on the surface, an observer can view the reflected images of the surroundings. The interface of a very rough surface will tend to reflect light at many different angles, because the light meets the surface at