Make your own Water prism.

Make your own Water prism. A prism is a transparent object that separates light into individual beams

Difficulty Level:

Elementary/Secondary

Concept: Dispersion of light, Spectrum, Prism

Introduction:

We can see a clear spectrum projected on a wall using a plane mirror and water in a vessel instead of a prism.

Materials:

a water container (Tupperware), a plain mirror, water, a wood stick/ruler

Procedure:

1. Put a plain mirror in the container slantingly as shown in Fig.5.
2. Fill the container half with water..
3. Put the container in the sunshine and adjust the lean of the mirror so that you can see a clear spectrum on the wall of the room

The stick is used to adjust the quantity of incident sunlight and get a clear spectrum.

Science of Prism:

A beam of white light like sunlight is split into seven colors of spectrum after being passed through a prism. This is because the refraction index for glass depends on the light color (=wavelength). The refraction index for violet light is a little larger than that for red light as shown in Fig.3. Fig.3 Spectrum made by prism In case of water prism, the combination of water and mirror works as a prism and make a spectrum on the wall of the room clearly as shown in Fig.4.