Why does current flow in a circuit?

Current flows in a circuit primarily due to differences in electric potential. When there is a voltage difference between two points in a circuit, it creates an electric field that pushes charge carriers, such as electrons, from the area of higher potential to the area of lower potential. This movement of charge carriers constitutes electric current.

In the context of cathodic protection systems, this principle is essential for understanding how protective currents are applied to mitigate corrosion. The varying potentials in the metals involved can significantly influence how current flows through the circuit, thereby affecting the effectiveness of corrosion protection strategies. Therefore, recognizing the role of potential difference is crucial in applications related to electrical circuits and cathodic protection methodologies.