Measuring current and voltage
Current is measured using an ammeter.
To measure the current flowing through a component in a circuit, an ammeter is always connected in series with the component.
Key points
When measuring current:
- current is measured in amperes, A;
- the current flowing through a component in a circuit is measured using an ammeter;
- the ammeter must be connected in series with the component.
There is a The potential difference across a cell, electrical supply or electrical component. It is measured in volts (V). (or potential difference) across an electrical component when an electric current flows through it.
Key point
Measuring The potential difference (or voltage) of a supply is a measure of the energy given to the charge carriers in a circuit. The unit this is measured with is volts (V). (voltage)
- voltage is measured in volts, V;
- the voltage across a component in a circuit is measured using a voltmeter;
- the voltmeter must be connected in parallel with the component.