A-level Current Electricity
Resistivity, potential dividers and EMF — AQA A-level current electricity (§3.5.1).
The full AQA A-level current-electricity section: charge and current from first principles, resistivity and how conduction changes with temperature, superconductivity, the circuit laws with energy and power, the potential divider as a sensing circuit, and EMF with internal resistance — including both required practicals.
Charge, current and potential difference
The fundamentals, from first principles up to the I–V characteristics.
Resistivity and conduction
Resistivity, its required practical, temperature effects and superconductivity.
Circuits, energy and power
Combining resistors and cells, conservation laws, and power.
Potential dividers, EMF and internal resistance
The potential divider as a sensor, and real cells with internal resistance.