What is electrical current measured in

Nevertheless, we must be clear in stating that the electric current is measured in terms of the amount of charge passing. A useful approach to getting over the idea of measuring electric current is to encourage the pupils to picture what is happening in the wires of the circuit — so starting with a teaching model.

You might start with the rope loop referring to the amount of rope that passes by each second. Then move on to the idea of the number of charged particles passing per second.

You might well explicitly connect the length of rope passing each second to the quantity of charge passing in each second. In introducing the ammeter, emphasise that its job is to measure how many charged particles pass through that point in the circuit each second. In such a way, talking about the ammeter helps to clarify and reinforce the concept of electric current. You could almost imagine that there is a little helper inside the ammeter.

You can measure current and potential difference in circuits. They are different things and so are measured in different ways. Current is measured in amperes. The symbol for ampere is A. For example, 20 A is a bigger current than 5 A. A device called an ammeter is used to measure current. This is analogous to an increase in voltage that causes an increase in current. Now we're starting to see the relationship between voltage and current.

But there is a third factor to be considered here: the width of the hose. In this analogy, the width of the hose is the resistance. This means we need to add another term to our model:. Need Help? Mountain Time: Shopping Cart 0 items. Charged particles are almost always electrons. Atoms in a conductive material have many free electrons that travel from atom to atom and everywhere in between. The movement of these electrons is random, so there is no flow in any direction.

However, when we apply a voltage to the conductor, all free electrons move in the same direction, creating a current. The current unit is ampere. Since the load is measured in coulombs and time in seconds, one ampere is the same as a coulomb in seconds.

Ordinary matter consists of atoms composed of positively charged nuclei and negatively charged electrons surrounding them.

The proton has times the mass of the electron, but has exactly the same size charge, not negative, only positive. The main consequence of this is that the proton and electron will attract each other strongly. Two protons or two electrons strongly push each other. The most commonly used device for measuring current is ammeter. Since the SI unit that measures the electric current is amperes, the device used to measure the current is called an ammeter.

There are two types of electric currents: direct current DC and alternating current AC.