An AC circuit is an electrical circuit that uses alternating current, where the flow of electric charge periodically reverses direction. This type of current is commonly found in household power supplies, allowing appliances to operate efficiently. The voltage in an AC circuit also varies sinusoidally, which means it oscillates in a wave-like pattern. In an AC circuit, components such as resistors, capacitors, and inductors can be used to control the flow of electricity. These components affect how the circuit behaves, including its impedance, which is the total opposition to current flow. Understanding AC circuits is essential for electrical engineering and various applications in everyday life.