Ham Amateur Radio Technician Practice Exam 2025 - Free Technician Practice Questions and Study Guide

The approximate open-circuit voltage from a fully illuminated silicon photovoltaic cell is around 0.5 VDC. This value arises from the semiconductor properties of silicon used in solar cells, where the built-in potential created by the p-n junction typically results in this voltage being produced when the cell is exposed to sunlight and operating under open-circuit conditions.

When no current flows out of the photovoltaic cell (open-circuit condition), it produces a voltage due to the separation of charge carriers (electrons and holes) generated by the absorbed light energy. This phenomenon is a fundamental principle of photovoltaic technology.

While other options suggest voltages that may be associated with different types of cells or specific conditions, the value of approximately 0.5 VDC is a standard output for silicon solar cells under ideal illumination. This is important for understanding how solar energy systems are designed and how silicon cells fit into the broader context of renewable energy technologies.