# How does AC work?

Alternating current (AC) works by periodically reversing the direction of electron flow in a conductor. In an AC circuit, the voltage applied to the circuit changes polarity over time, causing the current to reverse direction accordingly. This reversal occurs at the frequency of the AC supply, typically 50 or 60 cycles per second (hertz). As the voltage alternates between positive and negative cycles, electrons in the conductor move back and forth in response to these changes in voltage. This oscillatory movement of electrons constitutes the flow of AC current.

AC current does indeed cause electrons to oscillate back and forth along the wire at the frequency of the AC supply. When the voltage is positive, electrons are pushed in one direction through the circuit. As the voltage reverses to negative, electrons are pulled in the opposite direction. This back-and-forth motion of electrons is what constitutes the flow of AC current. It’s important to note that while electrons themselves move back and forth, the energy transfer (power) in an AC circuit is in the form of alternating electric and magnetic fields propagating along the conductor, rather than the physical movement of electrons over long distances.

AC current flows back and forth in a wire due to the periodic reversal of voltage polarity applied to the circuit. When an AC voltage source is connected to a conductor, the voltage alternates between positive and negative cycles. During each half-cycle, electrons in the conductor experience a push or pull depending on the polarity of the voltage. This causes electrons to move back and forth along the wire in synchronization with the alternating voltage. As a result, current flows in one direction during the positive half-cycle and reverses direction during the negative half-cycle, continually alternating at the frequency of the AC supply.

In a wire carrying AC current, the flow of electrons oscillates due to the alternating voltage applied across the circuit. As the AC voltage alternates between positive and negative values, it creates an electric field within the conductor. This electric field exerts a force on the free electrons in the wire, causing them to accelerate back and forth along the length of the conductor. The frequency of this oscillation corresponds to the frequency of the AC supply. The actual displacement of electrons is minimal—typically only a tiny fraction of a millimeter—yet this oscillatory motion constitutes the flow of AC current through the wire.