Which of the following determines ground losses for a ground-mounted vertical antenna operating on HF?

For a ground-mounted vertical antenna, the earth itself completes the electrical circuit by acting as the return path for the antenna's near-field currents. The amount of energy lost as heat during this process is directly determined by the soil conductivity. Highly conductive soils, such as saltwater marshes or rich, damp farmland, present very little electrical resistance, resulting in low ground losses. Conversely, poor conductors like dry sand or rocky terrain create high resistance and significantly reduce antenna efficiency. While factors like the standing wave ratio or take-off angle are important for overall station performance, they do not dictate the physical ohmic losses occurring within the earth beneath the antenna.