What is the primary role of negative electrical charges in a circuit?

The primary role of negative electrical charges in a circuit is to facilitate the flow of current. In an electrical circuit, current is defined as the flow of electric charge, which is typically carried by electrons. Electrons carry a negative charge and their movement through the conductive material creates an electric current.

In a circuit, when a voltage is applied, it creates an electric field that forces these negatively charged electrons to move, thus creating a flow of current. This flow, or current, is essential for powering devices and allowing electrical energy to be used effectively.

The roles of heat production, insulation, and resistance are related to electrical circuits but do not directly define the primary function of negative charges. Heat may result from the current flow due to resistance in conductors but is a byproduct rather than a primary role. Insulating wires is about preventing current from leaking, while increasing resistance is related to controlling the flow of current, rather than facilitating it.