AQA A-level Physics Series circuits
This page covers the following topics:
In a series circuit, the current at any point will be equal. As more lamps are added to a circuit, their brightness will decrease as less current will flow through them, although the current in the circuit will still be the same everywhere. If a component in a series circuit breaks, the circuit will become an open one and current will not flow.
In a series circuit, the total potential difference is equal to the sum of the potential differences across each component of the circuit. This is usually equal to the voltage of the cell or battery of the circuit.
The total resistance in the circuit will be the sum of all the individual resistances of the components.
All equations for the current, potential difference and resistance in a series circuit can be used together for calculations.
A variable resistor is connected in series with a cell and a fixed resistor of resistance 12 Ω. Given that the total resistance of the circuit is 20 Ω, calculate the resistance of the variable resistor.
A battery is connected in series with a resistor of resistance 15 Ω and a second resistance of unknown value. Given that the total resistance in the circuit is 22 Ω, calculate the unknown resistance.
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