What is the function of a transformer?

The function of a transformer is to increase or decrease voltage levels in an electrical system. This process is achieved through electromagnetic induction, where the transformer converts electrical energy from one voltage level to another while keeping the frequency constant.

Transformers have two windings: the primary winding connected to the source voltage and the secondary winding which delivers the transformed voltage to the load. The turns ratio—meaning the number of coils in the primary compared to the secondary—determines whether the voltage is stepped up or stepped down. This capability is essential in various applications, such as stepping up voltage for long-distance transmission, which reduces losses due to resistance in wires, or stepping down voltage for safe use in homes and businesses.

While other options include measuring current, switching circuits on and off, or reducing energy loss, these functions are performed by different devices or systems in an electrical network and are not the primary purpose of a transformer. Thus, the focus remains clearly on the voltage transformation capability that defines a transformer’s role in electrical systems.