Electricity

Electricity covers circuit symbols and diagrams, current, potential difference and resistance, series and parallel circuits, the IV characteristics of components, domestic electricity, power and the National Grid.

Series and parallel circuits are the foundation, and the rules differ in ways students routinely confuse: current is the same throughout a series circuit but splits in parallel, while potential difference splits in series and is the same across parallel branches. Getting these the wrong way round is the single most common error in the unit. IV graphs reward recognising the shape for a resistor, a filament lamp and a diode, and being able to explain each. Calculations use a small set of equations that must be known precisely. Two required practicals sit here, on resistance and on IV characteristics.