Question

Differentiate between regular and diffused reflection. Does diffused reflection mean the failure of laws of reflection?

Answer 1

Hint: Laws of reflection are universal. Both the reflections defer because of the surface quality. Regular reflection happens on smooth surfaces. Diffused reflection happens on rough surfaces. Diffused reflection can be thought of as multiple regular reflections.

Complete step by step answer:
If a bunch of parallel light beam incidents on the surface and the reflected beams are parallel, then it is called a regular reflection. The following figure shows regular reflection.

However, if the reflected beams are not parallel, then the reflection is considered to be a diffused reflection. The following figure shows the diffused reflection.

Another difference between regular and diffused reflection is the intensity of the reflected beam. As the light waves are diffused into different directions, the intensity of the light beam is always less than the incident beam.
The laws of reflection are universal laws, and diffused reflection does not mean that the laws of reflection are not working. The prime reason behind this phenomenon is that the irregular surface area of the reflecting surface. When the surface area is not smooth, the light beam reflects at different angles and the reflected light rays are diffused into different directions. That is why shiny objects often are smooth as well.
We need to consider the microscopic changes of the surface area to incorporate the effects of laws of reflection. As a result, we can say that the diffused reflection does not mean the failure of the laws of reflection. It is simply because of the uneven surface area of the reflecting material.

Note:
We need to know the definition of the fundamental laws to tackle this type of question with ease. In the optics, we only consider the regular reflection for the sake of simplicity. Dealing with diffused reflection is not possible because it incorporates the microscopic changes on the surface. Optics deals with ideal refractive or reflective materials. As a result, we can apply the laws of reflection easily.