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:
- Put a plain mirror in the container slantingly as shown in Fig.5.
- Fill the container half with water..
- 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.
