What is the primary function of a step-up transformer?

A step-up transformer is designed to increase the voltage of an alternating current (AC) electrical signal while decreasing the current proportionally. The primary function of this type of transformer is based on Faraday's law of electromagnetic induction, which dictates that when an AC voltage is applied to the primary winding of the transformer, it creates a magnetic field, inducing a higher voltage in the secondary winding when the number of coils in the secondary winding is greater than in the primary winding.

This increase in voltage is essential in various applications, such as power transmission over long distances where high voltage is needed to reduce energy losses that occur due to resistance in the wires. By stepping up the voltage, the current is reduced, allowing for more efficient transmission of electrical power. The concept is fundamental to understanding how transformers operate and plays a critical role in the design of electrical systems.