We can define an electric current as the flow rate of an electric charge past a certain point. This sort of current exists when we have a net flow of electric charges within a particular region. When we look at an electric circuit, we can see that the charge itself is carried by none other than electrons. The electrons move through the wire; this action can also be performed by ions within an electrolyte, or even a mixture of electrons and ions (this usually happens in an ionized gas like plasma)
The international unit measure of the electric current is known as the ampere. This refers to the electric charge flow across a certain surface, the rate being one coulomb a second. The current is measures with an ammeter.
Within an electric current, there are also charged particles that move about. These are known as charge carriers. When it comes to metals, one electron or more are loosely bound to their atoms. This leaves them to move about freely, therefore making the metal able to conduct electricity.
With this information, one might naturally ask just how many electrons are present in an electric current.
Electric current is what it is – a continuous flow of electrons which cannot be quantified unless you count them at a specific point they are passing by. An electric bulb can serve this purpose. In a 60-watt light bulb, for example, about 30,00,00,00,00,00,00,00,000 (3 followed by 18 zeros) electrons a second flow past any point in the wires to the bulb filament. However, their speed of travel is only a few centimeters every second.
We can also look at the fact that one coulomb is equal to 1/1.602 × 10^-19 = 6.24 × 10^18 electrons. Hence, an electric current that measures one ampere is equal to a single coulomb of electric charge that passes a certain point within a circuit in a second. This means that the current of one ampere will be 6.242 × 10^18 electrons moving past this point in a single second.
More About Electrons
The electrons that carry an electric charge through the wires are also called mobile electrons. Each electric circuit has an electric field direction, which is where the positive test charges go. The negatively charged electrons, on the other hand, go in the opposite direction from the electric field. The charge carriers are electrons when we’re talking about metal wires, though charge carriers for different circuits might be negative and positive charges that travel in opposite paths.
One traditional convention of physics is that positive charges are the only charge carriers. This was envisioned by Benjamin Franklin, who was responsible for extensively conducting research in the subjects of both current and static electricity. The direction of electric currents, then, is usually established in the direction of positive charges. Even if electrons move in the opposite manner, this convention remains in use for most of the world.