How can a cable pass signal I am currently study electrostatics. And I don't get how can electrons pass signals in a cable, can somebody explain this to me specifically?(I am only twelve years old) Thank you very much!
 A: You cable consists of (at least) one conductor, usually a metal wire. In a conductor, electrons are free to move. An electrostatic field, which you must have encountered in your studies, moves electrons. So if on one end of the wire we create a suitable field, electrons along the entire conductor will be slightly pulled towards or pushed away from the end. Hardly any actual motion occurs (after all, electrons repel each other!), but a measure of this force, the potential your electric field creates at one end of the conductor, is conducted to the other end because of it. There the recipient can measure it, hence receiving information about what was done on the other end.
The only practical way to use this is to have a return path. That can be a second wire or simply the ground (earth/oceans). Then what you apply is a potential difference between two wires, which has a special name: It is a voltage. In this setup, your transmitter connects (or disconnects) a battery or other voltage source to his two wire ends, and the receiver measures this voltage.
