- Circuits are a good way of showing the different components in an appliance.
- Each component has its own symbol and you must know the difference between them all and what they are.
- A battery consists of two or more cells connected together.
- Resistance (ohms) = potential difference (volts) / current (amperes)
- The current through a resistor at constant temperature is directly proportional to the potential difference across the resistor.
- The ammeter measures the current through an appliance. It is connected in series with the lamp so the current through them is the same.
- The voltmeter measures the potential difference across an appliance. It is connected in parallel so it measures the p.d across it.
- Electrons passing through an appliance…