The direction of light rays changes when they reflect from a surface, travel from one transparent medium into another or travel through a medium whose composition is continuously changing. When light travels through the different medium two phenomena happen. They are reflection and refraction. Let us now discuss what is the difference between reflection and refraction.
What is Reflection?
When a ray of light comes back into the same medium after striking the surface of another medium then the phenomenon is called reflection of light. In other words, reflection is the bouncing back of the light rays from a surface in the same medium.
What is Refraction?
The change of direction and speed of light as it enters from one medium to another is termed as the refraction of light. Examples of refraction are lenses, prism, telescope.
Difference between Reflection and Refraction in tabular form
The important difference between reflection and refraction:
|Description||Reflection is the bouncing back of light when it strikes a smooth surface.||Refraction is the bending of light rays when it travels from one medium to another.|
|Nature Of Surface||Generally occurs on shinny surfaces that only allow rebounding of light without permitting penetration through it.||This occurs in transparent surfaces that allow bending of the ray to a different medium.|
|Types||There are two forms of reflection, they are, Regular reflection (Specular reflection) and Diffused reflection.||There is a single form of refraction.|
|Occurrence||Occurs in mirrors.||Occurs in lenses.|
|Behaviour Of Light||In this process, light bounces back and returns back in the same direction.||In this process, light changes path i.e travels from one medium to another.|
|Speed Of Light||When a light ray strikes the boundary of a shiny surface the speed of light ray does not vary.||The speed of light varies with the medium in which the ray undergoes bending.|
|Medium Of Light Propagation||The medium in which light propagates remains the same.||The medium of propagation gets changed.|
|The angle of Reflection And Angle of Incidence||The angle of reflection and angle of incidence is the same in the case of reflection.||In refraction, the angle of reflection and angle of incidence are not the same.|
As we have seen the difference between reflection and refraction, let us now discuss some more details regarding reflection and refraction.
In simple terms, reflection implies the rebounding of light, sound, heat, or another object back to the source, without absorbing it. It changes the direction of the beam of light when it falls on the plane so that the ray goes back to the medium, in which it is generated.
The law of reflection says:
- The angle of incidence is identical to the angle of reflection.
- The ray of incidence, the ray of reflection, and the normal drawn at the point of incidence, to the mirror, occurs on the same plane.
Reflection can be of two types:
Regular reflection: Regular reflection is also termed as specular reflection, which occurs when the beam of light falls on a regular, polished, and smooth plane.
Irregular reflection: Irregular reflection also termed as diffuse reflection, which occurs when the beam of light falls on the rough surface and reflects light in various directions.
Refraction is the phenomenon of light, in which the wave is diverted when it passes diagonally through the interface between two media of different densities. It refers to the shift in direction and speed of the beam of light waves, because of the change in the transmission medium.
The Refractive index is the ratio of the angle of incidence to the angle of refraction. It determines the speed of a ray of light in the new medium. This implies that denser the medium the slow is the speed of light, and vice versa.
The law of refraction states that:
- The ratio of the sine of the angle of incidence and the sine of the angle of refraction is constant in any two given medium.
- The incident ray, the refracted ray and normal ray at the interface of any two given medium, all lie in the same plane.
There are various phenomena, which are based on refraction such as the apparent bending of an object that is partially submerged in water, and the mirages observed in a hot, sandy desert. The refraction of visible light is also an important characteristic of lenses that enables them to focus a beam of light onto a single point.
FAQs about Refraction and Reflection:
Q1. What do you understand by the power of a lens?
Answer: The power of the lens is the ability of a lens to converge or diverge light rays.
Q2. Which kind of mirrors is in use in the headlights of vehicles and why?
Answer. In headlights, Concave mirrors are in use to get the parallel beam of light.