What is the primary purpose of a transformer in electrical systems?

The primary purpose of a transformer in electrical systems is to change the voltage level of an electrical supply. Transformers operate on the principle of electromagnetic induction and are designed to either step up (increase) or step down (decrease) voltage levels in a circuit. This voltage adjustment is crucial for efficient power transmission over long distances, as higher voltages reduce current and minimize energy loss due to resistive heating in wires.

Transformers are widely used in power distribution systems and various electrical devices to ensure that the voltage levels match the requirements of different applications, maintaining the operation and safety of electrical systems. For example, high voltage generated in power plants can be safely transmitted through transformers to lower voltage levels suitable for residential or commercial usage.

In contrast, increasing the current in a circuit is not a function of transformers but rather relates to the characteristics of the load and the power supply. Transformer's main function is not to convert AC to DC; that process requires a rectifier. Measuring electrical output pertains to metering devices, not transformers. Therefore, changing the voltage level accurately defines the primary role of a transformer within electrical systems.