What force causes electrons to flow through a conductor?

The correct choice is electromotive force (EMF), which is the fundamental concept that causes electrons to move through a conductor. EMF refers to the voltage generated by a power source, such as a battery or generator, which creates a potential difference in an electrical circuit. This potential difference pushes the electrons, which are charge carriers in the conductor, facilitating their flow.

When EMF is applied across a conductor, it establishes an electric field that exerts a force on the electrons, compelling them to drift towards the positive terminal. The flow of electrons constitutes an electric current.

Voltage and EMF are closely related terms, but while voltage refers specifically to the potential difference between two points in a circuit, EMF encompasses the overall voltage produced by a source, which includes consideration of internal resistance and other factors within the source itself.

Resistance is a property of the conductor that opposes the flow of electrons, and power is the rate at which work is done or energy is converted in a circuit, but neither of these directly causes the electron flow. Understanding EMF is crucial for grasping how current operates in electrical systems.