An electrical circuit is a complete route that an electric current can flow around. The main aim of this earth leakage protection device is to detect faulty earth currents and to act by cutting the electrical circuit. In anelectrical circuit a capacitor will block direct current and will pass alternating current.
An electric circuit is a path in which electrons from a voltage or current source flow. The point where those electrons enter an electrical circuit is called the "source" of electrons. The point where the electrons leave an electrical circuit is called the "return" or "earth ground".