Sunday, 3 March 2013

3.12 explain some of the uses of electromagnetic radiations

  • radio waves: broadcasting and communications
    • Vibrations carry sound
  • microwaves: cooking and satellite transmissions
    • Vibrations create heat.
  • infra-red: heaters and night vision equipment
    • Vibrations create heat, cameras can detect where it is high and low to see by heat.
  • visible light: optical fibres and photography
    • Light reflected down tube to send signals, or onto film to take photos.
  • ultraviolet: fluorescent lamps
    • A coating inside the bulb will absorb UV light and re-emit it as visable light.
  • x-rays: observing the internal structure of objects and materials and medical applications
    • They pass through skin and soft tissue but reflect hard structures like bone.
  • gamma rays: sterilising food and medical equipment


  1. microwaves used for cooking foods because water molecules in the food absorb the microwaves and become very hot, food therefore cooks throughout - thought this could be added, since the specification said 'explain' :)

  2. gamma rays are sometimes used to kill tumours and cancerous cells in special cases. I thought you could add that in.

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