Calculate changes in energy when a system is changed by work done as current flows.

Electrical transfer questions use circuit quantities to track work done as current flows. In the Energy stores and systems subtopic, the transfer often links power and time, E = Pt, or charge and potential difference where that relationship is being used. The important distinction is that the energy pathway is electrical: a battery or power supply transfers energy to a component, which may then warm, move, or emit light. Good answers identify the electrical store and the receiving store before calculating the energy transferred.