Final answer:
An isolation transformer isolates appliances from high voltage by introducing high resistance between coils, reducing the risk of electric shock, while large circuit breakers use insulating gas to manage high voltage and current.
Step-by-step explanation:
An isolation transformer is an induction-based safety device that isolates an appliance from the high voltage of the original source, by placing a large resistance between them. This large resistance is due to the high-resistance material between the transformer coils, preventing a complete circuit and significantly reducing the risk of electric shock. In the case that someone touches only one of the transformer's output wires without grounding, the potential for current to flow through the person is very low, because the current would have to travel through a path with substantial resistance to complete a circuit.
Large circuit breakers designed for high voltage and current use insulating gas and gas jets to prevent and extinguish sparks that could maintain current flow during an interruption. This is particularly important in AC power systems, where the current drops to zero 120 times per second, offering frequent opportunities to quench any arcs.