Question

Explain two activities for the formation of artificial rainbow.

Answer 1

Activity - I:

1. Fill a glass with water
2. Place the glass on a table in front of a sunny window.
3. Place a sheet of paper on the floor. It could be any light color. White might be best, but try any color you prefer.
4. Wet the window with hot water.
5. Adjust the glass and the paper until you see a rainbow

Activity - II:

1. Take a tray and fill with water.
   
2. Place a mirror in water such that it makes an angle with the water surface.
   
3. Now focus white light on the mirror through the water.
   
4. Keep a white cardboard sheet above the water surface.
   
5. We may observe the colors VIBGYOR on the board.
   

The splitting of white light into different colors (VIBGYOR) is called dispersion. So a white light is a collection of waves with different wavelengths. Violet has the shortest wavelength and red has the longest wavelength.