Albert Teen YOU ARE LEARNING:  Measuring Current  # Measuring Current ### Measuring Current

Electric current is the flow of charge in a circuit, measured in amps. We can measure current using an ammeter.

Which one of these options is the most precise description of what electric current is? Which of the following is the correct unit for measuring electric current? Which of these pieces of equipment do you think we use to measure the electric current in a circuit? The electric current is the flow of charge in a circuit. We measure the current in amps. We use an ammeter to do that.

1

This image shows where in a circuit we would insert an ammeter to measure the electric current. We would not insert it where the voltmeter is inserted, because if we did that ...

A) the ammeter would not measure the whole electric current. B) the ammeter would measure more electric current than there is. C) there would be no space for us to insert the voltmeter.  2

We would insert an ammeter "in series", not "in parallel" like the voltmeter, because...

we want all of the electric current flowing through the ammeter. This will not happen if it is inserted in parallel. Does it matter at all of an ammeter introduces resistance into the circuit? An ammeter measures the flow of charge in a circuit. It has to be connected in series. If it is connected in parallel, it will not measure all the flow of charge in the circuit.

It also needs to introduce only very low resistance into the circuit. If it introduced high resistance, this would prevent a lot of the electric current flowing around the circuit, and that would pretty much defeat the point of using the ammeter to measure it.