Higher Physics

Particles and Waves - Activity 1B

Interference of microwaves

Aim - To  find the wavelength of microwaves from an interference pattern caused by reflected waves.     Instructions  - This experiment requires your computer to have a sound card and speakers installed.
The transmitter produces microwaves which are reflected from the metal reflecting plate on the right.  The reflected waves interfere with the waves transmitted from the transmitter.  The probe detects the strength of the combined waves and produces a sound which is loud at points of constructive interference and quiet at points of destructive interference. 
  • Click on the arrow to start moving the reflector from right to left.
  • Count the number of points of constuctive interference as measured by the probe.
  • Measure the distance travelled by the reflector.
  • Find the average separation between the maxima.
  • The maxima are one half wavelength apart.  Deduce the wavelength of the microwaves.
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