Electromagnetic spectrum

3.2.4 Dispersion of light

3.3 Sound

Electromagnetic spectrum

  1. Features

    1. Electromagnetic waves are transverse waves of varying wavelengths, which gives them different properties
    2. The longer the wavelength, the lower the frequency and the lower the energy
    3. The spectrum consists of, in order of wavelength: gamma rays, x-rays, ultraviolet, infrared, microwaves and radio
    4. The speed of electromagnetic waves in a vacuum is the speed of light: 299,792,458 ms-1
    5. Monochromatic radiation is radiation of a single wavelength
  2. Application

    1. Radio waves are used in radio and television communications, with television using higher frequencies, and is able to travel around obstacles due to diffraction and reflecting off the ionosphere
    2. Microwaves are used in satellite television and telephones, as it can travel through the atmosphere
    3. Infrared radiation is used in electrical appliances, such as remote controllers for televisions and intruder alarms
    4. X-rays are used in medicine, for radiographs and radiotherapy, and security, for inspecting the interior of luggage for threats