How is electric current defined?

Electric current is defined as the flow of electrons in a circuit. In electrical circuits, electrons move from areas of higher electrical potential to areas of lower electrical potential, creating what we refer to as electric current. This movement of charge carriers (electrons) is what allows electric power to be transmitted and utilized in various devices and systems. The definition encompasses not only the movement of the electrons themselves but also highlights the fundamental concept that current is a flow, typically measured in amperes.

The concept of electric current is foundational to the study of electricity and electrical engineering, as it describes how electricity is harnessed to perform work. This movement of electrons can be understood in terms of how it generates magnetic fields, creates voltage, and involves the transfer of energy in the form of electrical work.

Other options describe related but distinct concepts. The pressure that drives electrons can be thought of in terms of voltage or electromotive force, which are not direct definitions of current. Similarly, the flow of protons does not pertain to electric current, as protons are generally fixed within atomic nuclei and do not flow within conductors. Lastly, measurement of resistance is a separate concept relating to how much a material opposes the flow of current, rather than defining what current actually is