Which of the following best represents the flow of electric current?

The flow of electric current is best represented by the movement of electrons through a conductor. In conductive materials, such as metals, it is the negatively charged electrons that are free to move and create a current when a voltage is applied.

When discussing current, we often refer to the flow of electric charge; in most conductors, especially in metallic wires, it is the electrons that are responsible for this flow. The conventional direction of current is defined as the flow of positive charge, which is opposite to the direction in which electrons actually move. However, in practical terms, it is the movement of electrons that produces the detectable flow of current.

The other choices do not accurately depict electric current. Positive charge carriers may be relevant in certain contexts, such as in electrolytes or in semiconductor physics, but they do not dominate the typical conductive flow seen in metals. Static charges refer to stationary charges that can build up on surfaces but do not constitute a current since there is no movement. Magnetic fields crossing lines instead relate to electromagnetic induction and do not represent current flow directly. Hence, the movement of electrons through a conductor is the most accurate representation of electric current in this scenario.