What is the primary function of a transformer in an electrical system?

The primary function of a transformer in an electrical system is to modify voltage levels for efficient power transmission and distribution. Specifically, a transformer can step down voltage, which refers to reducing the voltage level while increasing the current proportionally, making it more manageable for powering devices at the end-user level.

Transformers operate on the principle of electromagnetic induction, allowing them to either increase or decrease voltage depending on the winding ratio of primary to secondary coils. In many applications, stepping down voltage is essential to ensure compatibility with residential and commercial devices that require lower voltage levels for their operation, helping to prevent potential damage from excessive voltage.

While transformers can also step up voltage, the focus in this context is on their role in providing a safe and usable voltage for consumers. Other options like controlling current flow or providing backup power do not accurately represent the fundamental purpose of a transformer. Instead, devices like circuit breakers or uninterruptible power supplies serve those specific functions.