Refraction of Light through prism | Dispersion of Light explained | Science Experiments for kids
Light Dispersion and refraction through prism.
Have you ever noticed that diamonds sparkle in sunlight? Ever wondered why?
They sparkle and give seem to be giving out different colors.
Just like oil spilt on any surface showcases different colors.
The reason behind these phenomena is the diffraction of light.
Before we understand what refraction is let us conduct this easy and cool experiment of extracting a rainbow from white light
For this experiment, you'll need
• Prism
• White light
• And a dark room where the refraction can be clearly seen.
Procedure:
• Take the prism and keep it on the table.
• Ensure that the room is considerable dark for this light to be obvious.
• When light travels through the prism, it splits the white light in to 7 colors. These are Violet, Indigo, Blue, Green Yellow Orange and Red. They appear in the same order , just like in the rainbow.
• Observe the light ray carefully inside the prism. Notice that the light ray bends at two different points - one when the light is entering the prism and another when it leaves the prism.
Question is -why is the light being dispersed into the rainbow colors?
Explanation:
Prism is made up of glass. The seven different colors coming out of the prism constitute seven different wavelengths. Each color represents a different wavelength of light. These different wavelengths travel at different speeds in glass. This is the main reason for the formation of rainbow or spectrum when the light travels through the prism. Another point to be noted here is that the angle of refraction is different for these colors as they have different wavelength.
When light touches the surface of the prism, refraction takes place at the boundary of the prism i.e. boundary between air and glass. Then e white light is separated into its component colors - red, orange, yellow, green, blue and violet.
Refraction is the change in direction of a wave due to a change in its medium.
When these wavelengths reach the other side of the prism at different angles, refraction takes place at the surface of the prism i.e. at the boundary of the glass and prism and the angle of refraction is greater when they leave the prism.
This separation of visible light into its different colors is known as dispersion. All these colors constitute the spectrum.
The angle of refraction which a light undergoes when it travels from one medium to another medium is determined by the refractive index of the given medium.
This is the reason why the diamond sparkles in broad daylight and makes it shiny.
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