When a ray of light falls on a medium, it is either absorbed, transmitted or reflected. All these three phenomena are associated with the wave nature of light. In this article, we are going to discuss the reflection of light in particular. It can be defined as the bouncing back of waves after striking with an interface of two different media. The objects that are not capable of reflecting light, are not capable of being seen.
Reflection of Light Types
Reflection of light is of two types –
Specular or Regular Reflection
When a ray of light falls on an extremely polished surface, the angle of incidence is equal to the angle reflection, made with the surface normal. Regular reflection occurs in plane mirrors.
There are three laws of reflection for a Regular reflection from a plane mirror:
a. The incident ray reflected ray and the normal to the mirror all lie on the same plane.
b. The angle of incidence is equal to the angle of reflection. Both angles are measured with respect to the surface normal.
c. The reflected ray and incident ray are on opposite sides of the normal.
Practice with: Chemistry Sample Paper and Maths Sample Paper
Diffuse or Irregular Reflection
When a ray of light falls on a surface and gets scattered at different angles in different directions then it is known as diffuse reflection. Diffuse reflection is the reason why we are able to see things around us. It is the reason for our visibility.
How do we see things?
Human eye has a biconvex lens and it performs two important functions:
- Focusing image on retina
- Refraction of light
Retina and lens work together to provide us visibility. it is obvious from the diagram that light traveling in air, strikes the surface of the cornea and the bending of light occurs. Hence, along with reflection, refraction is also an important aspect of the mechanism by which images are formed in our eyes.
The refracting ray emerging from cornea if a bit converged and falls on the lens which converges it further. When the light ray exits the lens it falls on the retina and an image is formed in an inverted manner.
Summarized Notes On Reflection Of Light
- When a light ray falls on an interface and returns back to travel in the same medium then it is known as a reflection of light.
- Specular and diffuse are two types of reflection. Specular reflection occurs through polished surfaces while diffuse reflection occurs through rough surfaces
- Diffuse reflection is the reason for our visibility.
- The objects which do not reflect light are not visible.
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