After completion of this lesson, student must be able to:

  • Define refraction.
  • Explain the refraction.
  • Describe the nature of the electromagnetic spectrum.
  • Describe dispersion of light.
  • Describe the practical uses of electromagnetic spectrum.



Light is a form of energy which produces the sensation of sight. When a light rays travels from rarer to a denser medium, it bends towards the normal. This note gives us the information about light and refraction of light.

Causes of Refraction of Light

The change in speed of light when it passes from one medium to another is the cause of the refraction of light. This note gives us further information about causes of refraction of light.

Electromagnetic Waves

Electromagnetic waves are the waves which carry energy by the variations of electric and magnetic fields. Infrared radiation, visible light, and ultraviolet radiation are examples of Electromagnetic waves. This note provides information about electromagnetic waves.