ISA Utility Specialist Practice Exam

The primary function of a transformer is to raise or lower voltage through induction. This is accomplished by utilizing two sets of coils, known as the primary and secondary windings, which are wound around a core. When alternating current passes through the primary winding, it creates a magnetic field that induces a voltage in the secondary winding. Depending on the turns ratio of the windings, the transformer can increase (step-up) or decrease (step-down) the voltage while maintaining the same power level (ignoring losses).

This voltage transformation is essential for effective long-distance electrical transmission and distribution, where high voltages are needed to reduce energy losses, and lower voltages are required for safe usage in homes and businesses. The ability to change voltage levels without altering the frequency is a fundamental characteristic that defines the operational purpose of transformers in electrical systems.