When an open circuit to earth ground is detected, the G.F.I. device immediately opens the voltage source to the device. G.F.I. devices are similar to circuit breakers but are designed to protect humans rather than circuit components.
A circuit diagram or wiring diagram uses symbols to represent parts of a circuit.
One way to make this topic more accessible is to use analogies (Lakoff and Johnson 2008). Analogies are examples which possess similar features, or work in a comparable manner, to the ideas that you wish to teach (Harrison and Coll 2007). They offer an excellent method of visualising difficult and unfamiliar concepts, or ideas that can not be directly seen.
Electric circuits are different than electronic circuits.