Measuring resistance

The current through a component can be measured using an ammeter.
- This must be connected in series with the component.
- Ammeters have very low resistance so that they don’t change the current in the circuit.
The potential difference across a component can be measured using a voltmeter.
- This must be connected in parallel with the component.
- Voltmeters have very high resistances so that very little current flows through them.
The resistance of a component can be found by measuring the current through it and potential difference across it.
- A variable resistor can also be used to vary the current through the component.
- By taking potential difference readings for multiple currents, it can be determined how the resistance changes for non-ohmic conductors.

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