# Voltage

is a measure of the difference in electrical energy between two parts of a circuit. The bigger the difference in energy, the bigger the voltage.

Voltage is measured in volts. The symbol for volts is $$V$$. For example, $$230V$$ is a bigger voltage than $$12V$$.

## Measuring voltage

Voltage is measured using a . Some types of voltmeter have a pointer on a dial, but most have a digital readout. To measure the voltage across a in a circuit, you must connect the voltmeter in with it.

Circuit with cell, lamp and voltmeter. The voltmeter is connected in parallel to the lamp

You can measure the voltage across a cell or . The more cells, the bigger the voltage.

Two circuits with different voltages