Potential difference (p.d.) is defined as the energy dissipated by a component in a circuit, such as a resistor, rather than the work done in moving a unit charge between two points. In contrast, electromotive force (emf) represents the work done by a source in moving a unit charge across a circuit. The distinction emphasizes that while emf is the energy supplied, p.d. reflects energy consumed. Understanding this difference is crucial for analyzing electrical circuits accurately. The clarification helps in grasping the roles of emf and p.d. in energy transfer within circuits.
