Are a transformer's primary winding and secondary winding connected together?

In the context of transformers, the primary winding and secondary winding are not directly connected together. Instead, they operate through electromagnetic induction. When an alternating current flows through the primary winding, it creates a magnetic field that induces a voltage in the secondary winding. This means that the energy transfer between the primary and secondary sides occurs without a physical connection, reinforcing the principle of isolation between the two windings.

This isolation helps in providing safety and separation of different voltage levels, allowing transformers to step voltages up or down as required without direct electrical connection. The primary and secondary sides can operate at different voltage levels and are typically contained within the same transformer housing, but they maintain unique circuit paths.

The incorrect options suggest either a direct connection, indirect connection, or specificity to step-down transformers, which misrepresent the fundamental operation of how transformers work. Thus, understanding the principle of electromagnetic induction clarifies that the correct response is that the primary and secondary windings are indeed not connected.