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In I/GCSE Physics, it belongs to core physic. The details of electric circuits will be discussed in the following.

Circuits

- When electric charges move in a wire, we say that an
**electric current**flows in the wire. It's like the way a current of water flows in a river. - For an electric current to flow, we need two things:

- something to make the electricity flow, such as a battery or power pack
- a complete path for the current to flow in. This is called an
**electric circuit**.

Voltage

- 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.
- Voltage is measured using a voltmeter.

Resistance

- Resistance is measured in ohms. It can be calculated from the potential difference across a component and the current flowing through it. The total resistance of a series circuit is the sum of the resistances of the components in the circuit.
- An electric current flows when electrons move through a conductor. The moving electrons can collide with the atoms of the conductor. This makes it more difficult for the current to flow, and causes resistance.

That's all!