Refraction of light

• Refraction is the bending when light travels from one medium to another due to the change in speed of the ray of light.

  
• • The emergent ray is parallel to the incident ray only if the sides of the glass are parallel)
  • i = angle of incidence, r = angle of refraction

  
• Light put in at one end is totally internally reflected until it comes out the other end.

  
• • Application: Optical Fibres
  • Used in communications: signals are coded and sent along the fiber as pulses of laser light
  • Used in medicine: an endoscope, an instrument used by surgeons to look inside the body; contains a long bundle of optic fibers.