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Activity Discussion Science & Technology How do prisms make rainbows?

  • Aruja

    May 6, 2021 at 8:35 am
    Not Helpful

    First of all what is a prism? a prism is a transparent refractive medium, which has two triangular bases and three rectangular plane surfaces. The transparent beam of light is made up of seven colours these are VIBGYOR ( V=violent, I=indigo, B=Blue, G=green, Y=yellow, O=orange, R=red ). As we know that these are the colours present in a rainbow as well. When we passes a transparent beam of light through the prism that is a transparent refractive medium, which splits that single beam of light into the seven colours this phenomenon is called dispersion of light. The process of obtaining band of seven colours obtained from the beam of light is called the spectrum of light.

    Isaac Newton was the first one to use a glass prism to obtain the spectrum of light.

    Now we can see that the spectrum that is formed through the prism it gives a figure of the rainbow. But actually a rainbow is a natural spectrum that is appeared in the sky after the rain shower. It is formed when dispersion of sunlight happens through the tiny water droplets that act as a transparent refractive medium present in the atmosphere. The sunlight refract and disperse the incident sunlight, then reflect it internally and finally, refracted again when it comes out of the raindrop which finally gives us the seven different colours which results in a actual rainbow. Spectrum of light obtained through the prism is a lab experiment to show the spectrum of light and phenomenon of dispersion.

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