<P> In a conductive material, the moving charged particles which constitute the electric current are called charge carriers . In metals, which make up the wires and other conductors in most electrical circuits, the positively charged atomic nuclei are held in a fixed position, and the negatively charged electrons are free to move, carrying their charge from one place to another . In other materials, notably the semiconductors, the charge carriers can be positive or negative, depending on the dopant used . Positive and negative charge carriers may even be present at the same time, as happens in an electrolyte in an electrochemical cell . </P> <P> A flow of positive charges gives the same electric current, and has the same effect in a circuit, as an equal flow of negative charges in the opposite direction . Since current can be the flow of either positive or negative charges, or both, a convention is needed for the direction of current that is independent of the type of charge carriers . The direction of conventional current is arbitrarily defined as the same direction as positive charges flow . </P> <P> The consequence of this convention is that electrons, the charge carriers in metal wires and most other parts of electric circuits, flow in the opposite direction of conventional current flow in an electrical circuit . </P> <P> Since the current in a wire or component can flow in either direction, when a variable I is defined to represent that current, the direction representing positive current must be specified, usually by an arrow on the circuit schematic diagram . This is called the reference direction of current I . If the current flows in the opposite direction, the variable I has a negative value . </P>

What is the actual direction of electric current