Measuring current and voltage
You need to know how to measure the current that flows through a component in a circuit and the voltage across it.
Measuring current
Current is measured in amperes. Amperes is often abbreviated to amps or A. The current flowing through a component in a circuit is measured using an ammeter. The ammeter can be placed anywhere in the circuit. Remember that the current is the same in all parts of a series circuit.
Voltage
A voltage (or The potential difference (or voltage) of a supply is a measure of the energy given to the charge carriers in a circuit. Units = volts (V). This is the voltage between two points that makes an electric current flow between them.) across an electrical component, such as a lamp, is needed to make a current flow through it. Cells or batteries often provide the voltage needed.
Measuring voltage
Voltage is measured in volts, often abbreviated to V.
The voltage across a component in a circuit is measured using a voltmeter.
The voltmeter must be connected in parallel with the component.