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Communication using cables

Total internal reflection

This video shows how total internal reflection works, and demonstrates how it can be used to make a coin appear invisible from a certain angle. This behaviour of light waves is crucial to fibre optic technology in the real world.

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Key learning points:

  • Light travels down an optical fibre by total internal reflection.
  • Optical fibres are used in telecommunication to carry information over large distances.
  • A laser beam should never be directed towards eyes as it can damage eyesight.


A picture of wave reflection.

Class Clips

Video clip explaining the principle of reflection with lasers and water waves


Wave refraction

Class Clips

Video clip demonstrating total internal reflection


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Tombstone Timeout

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