What does electrical current represent in a circuit?

Electrical current in a circuit is defined as the flow of electric charge, and in most conductive materials, this charge is carried by electrons. When a voltage is applied across a conductor, such as a wire, it creates an electric field that prompts the electrons to move, resulting in a current flow.

Electrons, being negatively charged particles, are the primary carriers of electric current in metal conductors. As they move through the circuit, they transfer energy and allow devices to function, driving the operation of everything from simple light bulbs to complex electronic systems.

The other options represent fundamental particles but do not participate in the flow of electricity in typical conductive materials. Protons are found in the nucleus of an atom and do not move freely in conductors, while neutrons are also found in the nucleus and do not carry a charge. Photons are particles of light and do not contribute to electric current in circuits as they relate to electromagnetic radiation rather than the flow of electric charge. Therefore, the representation of electrical current by electrons is fundamental in understanding how circuits operate in practice.