What is the purpose of a step-up transformer?

The function of a step-up transformer is to increase the voltage from the primary coil to the secondary coil. This increase in voltage is achieved through the turns ratio of the transformer, meaning that there are more turns of wire in the secondary coil compared to the primary coil. As a result, when alternating current (AC) passes through the primary coil, it creates a magnetic field that induces a higher voltage in the secondary coil due to this greater number of turns.

In electrical systems, step-up transformers are commonly used in applications where electricity needs to be transmitted over long distances. Elevating the voltage reduces current in the transmission lines, which minimizes energy losses that occur due to resistance in the wires. Therefore, the primary role of a step-up transformer is vital for efficient power distribution.

While other options provide functions related to electrical systems, they do not align with the primary purpose of a step-up transformer. For instance, converting AC to DC refers to the role of rectifiers, while decreasing voltage describes the function of a step-down transformer. Maintaining constant voltage relates to voltage regulators, which stabilize output despite variations in input or load conditions.