What is the main purpose of a transformer?

The main purpose of a transformer is to transfer electrical energy between circuits while also stepping up or stepping down voltage levels as necessary. This process occurs through electromagnetic induction, where an alternating current in the primary coil creates a magnetic field that induces a current in the secondary coil. The ability to change voltage levels makes transformers essential in electrical power distribution, enabling efficient transmission over long distances and safe utilization in homes and industries.

By stepping up voltage, transformers minimize energy loss during transmission, while stepping down voltage ensures that the electricity is at a usable level for devices and appliances. This is fundamental in power systems, where high transmission voltages decrease the current and reduce resistive losses over long distances.

Other options address related concepts but do not accurately reflect the core function of a transformer. While storing electrical energy is related to capacitors, converting mechanical energy to electrical energy pertains to generators, and regulating voltage levels without changing frequency is more aligned with other devices like voltage regulators, which do not encompass the main role of a transformer itself.