Supercharge Your Skills: Ace the 2025 Electronic Technician Apprentice Exam with Confidence!

The correct choice identifies the fundamental principle of how a transformer operates to increase voltage. A transformer consists of two coils of wire, known as the primary and secondary coils, wrapped around a core. When an alternating current (AC) flows through the primary coil, it creates a magnetic field that induces a voltage in the secondary coil.

To increase the voltage in the secondary coil, the transformer must have more turns of wire in the secondary coil compared to the primary coil. This relationship is described by the transformer equation, which states that the voltage across the coils is proportional to the ratio of their turns. Therefore, if the secondary coil has more turns, it will produce a higher voltage output as the magnetic field strength generated by the primary coil induces a higher voltage in the secondary coil due to this additional number of turns.

This method of utilizing the turns ratio is essential for transformers to effectively step up voltage levels for various applications in electrical systems, such as in power distribution.