Final answer:
An isolation transformer has no direct electrical connection between the primary and secondary windings. It puts a large resistance between the original voltage source and the device being operated, preventing a complete circuit between them.
Step-by-step explanation:
An isolation transformer has no direct electrical connection between the primary and secondary windings. It is designed to put a large resistance between the original voltage source and the device being operated, preventing a complete circuit between them. This safety feature protects the user from electric shock because the current flow is negligible through the high-resistance material between the transformer coils, through the wire, the person, and back through the earth.