Electricity and Magnetism

5B20.35: Faraday Cage

small radio in cagelarge radio in cage
Description: Radio waves, being electromagnetic in nature, do not penetrate the metal cage because the cage acts as a vertical and horizontal polarizer.
Since radio waves do not enter the Faraday cage, the radio will loose reception.

Equipment: Setup Procedure:
  1. Tune the radio to an AM station.
  2. If using the radio with no onboard speaker, connect to an external speaker.
  3. Test to make sure the radio looses the signal when put inside the faraday cage.
Demonstration Procedure:
  1. Turn the radio on and note that it picks up the AM radio station.
  2. Place the radio inside the faraday cage and put the cover on top.
  3. Note that the radio looses the signal since E&M waves don't enter the cage.
Note: Works best with an AM station. Also, the finer the wire mesh, the better it blocks the radio waves.