Which of the following is not a function of a transformer?

A transformer is primarily used to transfer electrical energy between two or more circuits through electromagnetic induction. One of its essential functions is changing voltage levels, which allows it to step up (increase) or step down (decrease) the voltage for efficient power transfer across the electrical grid or for various electrical devices.

Transformers also transform current levels as a part of their operation. According to the principle of conservation of energy, if the voltage is increased, the current must decrease, and vice versa, given that the power (voltage multiplied by current) remains relatively constant (ignoring losses). Therefore, changing current levels is inherently related to the transformer’s role in adjusting voltage levels.

Modifying impedance is another function of transformers, particularly in applications like matching the impedance of different components in a circuit to optimize power transfer and reduce reflections in transmission lines.

Generating electricity, however, is not a function of a transformer. Transformers do not create electrical energy; they simply convert energy from one voltage level to another. This distinction is crucial in understanding the role and limitations of transformers in electrical systems.