NIOS Class 10 Science Activity 15.6 Light Energy

This activity demonstrates how a prism splits sunlight into seven colours, forming a spectrum.

Dispersion of Light Through A Prism

Light Energy Activity

This activity is based on the NIOS Class 10 Science and Technology (212) Chapter 15: Light Energy, Module 4.

Aim

 To study the phenomena of Dispersion of Light

Materials Used

   1. Cardboard box

   2.  Whitepaper

   3. Glass prism

   4.  Knife

   5.  Light source (sunlight)

Procedure

We take an empty cardboard box and make a rectangular opening on its cover. We paste a sheet of transparent white paper over this opening.

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 On the opposite side of the box, we cut a thin slit using a knife. We place a prism on a block inside the box in the path of light and turn the slit side towards the sunlight so that sunlight enters the box through the slit. We observe the transparent white paper.

Observation

We see coloured strips appear on the transparent white paper. There are seven colours – violet, indigo, blue, green, yellow, orange, and red.

Explanation

Sunlight is made up of seven different colours. When sunlight passes through a prism, each colour bends at a different angle due to refraction.

Violet colour deviates maximum and red colour deviates minimum.

These seven colours - violet, indigo, blue, green, yellow, orange, and red (VIBGYOR) form a strip on the screen, and this colourful strip is called the spectrum.

The phenomenon of splitting of white light into seven colours is called dispersion of light.

Conclusion

 This activity proves that sunlight is made up of seven colours. The activity also explains the ‘Dispersion of light’.

Frequently Asked Questions

   1. What is the dispersion of light?

Answer – The splitting of white light into seven colours when it passes through a prism is called dispersion.

   2. Which colour bends the most in the prism?

Answer - Violet

   3. Which colour deviates the least in the prism?

Answer – Red

   4. What is VIBGYOR?

Answer – The band of seven colours on the screen.

   5. Who discovered that sunlight is made up of seven colours?

Answer – Isaac Newton