A step-down transformer's secondary winding is connected to what?

In a step-down transformer, the secondary winding is specifically designed to reduce voltage from the primary side to a lower voltage on the secondary side. This lower voltage allows the electrical energy produced by the transformer to be more suitable for the devices or systems that consume it, known as the load. By connecting the secondary winding directly to the load, the transformer fulfills its primary purpose of voltage regulation, ensuring that the equipment receives the appropriate voltage required for optimal operation.

Additionally, when considering the other options, the ground typically serves as a safety measure and is not a direct connection for power transfer in the context of how transformers work. The power source would be connected to the primary winding of the transformer, not the secondary. Connecting to another transformer is not the intended function of the secondary winding in a step-down configuration; this winding is meant to directly supply power to a load situated downstream in the electrical system.