In electrical circuits, the movement of electric current is not the movement of individual electrons traveling at nearly the speed of light. Instead, it is the propagation of electromagnetic waves or signals through the conductive medium, such as wires.
The speed at which electric current travels in a wire is determined by the properties of the medium and the way in which the electromagnetic waves propagate. In general, the speed of electric current is slower than the speed of light in a vacuum due to several factors:
Interaction with the medium: When an electric current flows through a conductor, it interacts with the atoms or molecules of the material. These interactions cause delays and collisions, which slow down the propagation of the electromagnetic wave. In materials with higher resistance, such as metals, there are more collisions and interactions, resulting in slower propagation speeds.
Signal velocity: The speed at which electromagnetic signals propagate in a medium is governed by the velocity of the electric and magnetic fields. This velocity is determined by the properties of the material, such as its permittivity and permeability. In most conductive materials, including metals, the signal velocity is slower than the speed of light due to the influence of these material properties.
It's important to note that the speed of electric current in a wire is not determined by the individual electron speed. Electrons themselves actually move relatively slowly in a current-carrying wire, drifting at an average speed called the drift velocity. The drift velocity is typically much slower than the speed of light, even in conductive materials. However, when an electric field is applied to a circuit, it creates a chain reaction that results in the propagation of an electromagnetic wave through the conductive medium at speeds that depend on the factors mentioned above.
In summary, the speed of electric current in wires is determined by the properties of the medium and the interactions between the electric current and the conducting material. While the speed of electric current is typically slower than the speed of light, it is still fast enough for practical applications, allowing for the transmission of electrical signals and energy over long distances in a relatively short amount of time.