Which of the following is true regarding vertical antennas?

Vertical antennas are designed to radiate radio frequency energy in a way that typically produces a vertical polarization. In this context, the electric field generated by the antenna is oriented in a direction that is perpendicular to the Earth's surface. This characteristic is fundamental to how vertical antennas function and interact with the surrounding environment.

The orientation of the electric field is significant because it affects how signals propagate and how they can be received by other antennas. When vertical antennas are used, their primary radiation pattern typically has the strongest emissions at a broad angle to the ground, which is beneficial for communicating over long distances, especially in urban areas where obstacles may scatter signals.

Further, the specific mention of the magnetic field being perpendicular to the Earth is not correct as the overall radiation pattern of a vertical antenna consists of both electric and magnetic fields, which are at right angles to each other, but the correct description of the electric field’s orientation confirms the behavior we expect from vertical antennas. This is crucial for understanding antenna design and function in radio communication.