Which transformation type would decrease voltage from a high level to a lower level?

A step-down transformer is specifically designed to reduce voltage from a higher level to a lower level. It achieves this by having a primary winding with more turns of wire than the secondary winding. When an alternating current flows through the primary winding, it creates a magnetic field that induces a smaller voltage in the secondary winding. This ability to decrease voltage makes step-down transformers essential in electrical distribution systems, where high voltage needs to be lowered for safe use in homes and businesses.

In contrast, a step-up transformer increases voltage, making it unsuitable for decreasing voltage. Smart transformers refer to advanced units equipped with technology for managing power flows and enhancing efficiency but do not inherently denote a reduction in voltage. An autotransformer may also adjust voltage levels; however, it operates differently and can step up or step down voltage depending on how it is configured, making it less clear-cut for this specific function of reducing voltage compared to the definitive function of a step-down transformer.