Most people think that electrons move very fast, speed of light, inside of an electrical circuit. But guess what?! They don't. Electrons move about a meter and a half per hour or .4cm per second! The reason then that things in electrical circuits are instant is because of the effect of the energy. Imagine that you had a pipe with ball bearing in it going from california to florida. If the pipe was full and you pull another ball bearing in it, then one would instantly pop out on the other side. But how fast are they moving? Pretty slow.