This experiment shows how a cell phone, can lose it's connection by being wrapped in aluminum paper and when trying to call it, nothing happens. But why does this happen? Lets see: It is known that cell phones send and recieve information by radiocommunication and these are transmitted from the phone to the nearest base station (Switching centre) and the signal recieved is sent by this Switching centre to the cell phone with a slightly different frequency Illustration 1: Example of a telephone switching center connecting 2 cell phones Besides this, these are coverage areas of the operators called cells, where in each one there is a base station, has an amplitude to emit and receive information. It is understood that a mobile device moves or changes its position around to the cell tower, the magnetic flux passing through the antenna also changes due to the variation in angle and distance. This magnetic flux variation creates an electric movement induced in the antenna of the device. Ilustración 2: Example of a mobile phone base. “Lost Call” When in the experiment the cell phone has the aluminum foil placed around, it acts as a "Faraday cage", this is a structure designed to block the entry or exit of electromagnetic fields, where electromagnetic waves are prevented from entering the interior of the object, since aluminum is induced, causing the magnetic field to interfere with the original (electromagnetic field that would go to the cell phone). When the aluminum foil has the electrons located on the external surface, an electric field is produced that cancels the external field, causing them to reach a field value equal to zero inside the cage, making their magnetic flux zero. The electromotive force in the cell phone, generated by its antenna and the cell phone network, is affected by the aluminum foil. The cell phone's electromotive force is used to amplify and process the electromagnetic signals that receives and to transmit the signal it emits. By wrapping your cell phone in aluminum foil, you are partially or completely blocking electromagnetic waves from reaching the antenna, which decreases the antenna's ability to generate adequate electromotive force and process signals. As a result, the mobile phone signal is weakened or cut off.
