Explain two activities for the formation of artificial rainbow?

Activity - I:

  1. Select a white coated wall on which the sun rays fall.
  2. Stand in front of a wall in such a way that the sun rays fall on your back.
  3. Hold a tube through which water is flowing.
  4. Place your finger to obstruct the flow of water.
  5. Water comes from small gaps between the tube and figures like a fountain.
  6. Observe the changes on wall while showering the water.

Activity - II:

  1. Take a metal tray and fill it with water.
  2. Place a mirror in water such that it makes an angles with water surface.
  3. Now focus white light on the mirror through the water.
  4. Keep a white card board sheet above the water surface as shown in figure.
  5. We may observe the colours VIBGYOR on the board.
  6. The splitting of white light into different colours (VIBGYOR) is called dispersion.
  7. So consider a white light is a collection of waves with different wavelength.
  8. Violet has shortest wavelength and red has longest wavelength.