What is the main purpose of a transformer in electrical circuits?

The main purpose of a transformer in electrical circuits is to change the voltage level of an alternating current (AC) signal. Transformers operate on the principle of electromagnetic induction and are typically used to either step up (increase) or step down (decrease) the voltage of an AC signal while maintaining the same frequency. This voltage alteration is essential in power transmission and distribution systems, allowing efficient transport of electricity over large distances. When the voltage is increased, less current flows through the transmission lines, minimizing energy losses due to resistance.

While there are various electrical devices with distinct roles, such as converting AC to DC, reducing power consumption, or acting as safety devices, these are not the primary functions of a transformer. The transformer's role is crucial in adapting voltage levels for different applications, enabling devices to operate correctly and safely within their specified voltage ranges.