What is the primary function of an autotransformer?

The primary function of an autotransformer is voltage transformation. An autotransformer operates using the principle of electromagnetic induction and has a single winding that serves as both the primary and secondary winding. This design allows it to efficiently change the voltage levels in an electrical circuit.

In an autotransformer, a portion of the winding is common to both the input and output, which makes it different from conventional transformers that have separate primary and secondary windings. By tapping into different points on the winding, an autotransformer can step up or step down voltage to the desired level, making it an effective and efficient solution for applications that require voltage adjustments.

Other options like current restriction, power generation, and signal amplification do not align with the primary role of an autotransformer. While an autotransformer does affect current indirectly due to the changes in voltage, its main purpose clearly revolves around altering voltage levels to meet specific requirements in various applications.