Applications of EM Waves (Edexcel IGCSE Physics)

• Each region of the electromagnetic spectrum has a variety of uses and applications

Uses of EM waves

Wave Type	Uses
Radio	Broadcasting and communications
Microwaves	Cooking and satellite transmissions
Infrared	Heaters and night vision equipment
Visible light	Optical fibres and photography
Ultraviolet	Fluorescent lamps
X-rays	Observing the internal structure of objects and materials, including medical applications
Gamma rays	Sterilising food and medical equipment

Radio waves & microwaves

• Both radio waves and microwaves are used in wireless communication
• This includes:
  • Radios
  • Air traffic communication
  • Mobile phone communication
• At very high intensities microwaves are used to heat things in a microwave oven

Infrared

• Infrared is emitted by warm objects and can be detected using special cameras (thermal imaging cameras).
• Examples of the uses of infrared are:
  • Security cameras to see people in the dark
  • TV remote controls
  • Transport signals down fibre optic cables

Visible

• Visible light is the only part of the electromagnetic spectrum that the human eye can see
• It is also used in fibre optic communication

Ultraviolet

• Ultraviolet is responsible for giving you a sun tan, which is your body’s way of protecting itself against the ultraviolet
• When certain substances are exposed to ultraviolet, they absorb it and re-emit it as visible light (making them glow)
  • This process is known as fluorescence
• Fluorescence can be used to secretly mark things in special ink, such as banknotes

X-rays

• The most obvious use of x-rays is in medicine
• X-rays can pass through most body tissues but are absorbed by the denser parts of the body, such as bones

Gamma Rays