ARRL Technician Practice Exam

Which of the following is true regarding vertical antennas?

1. The electric field is parallel to the Earth

2. The electric field is perpendicular to the Earth

3. They are primarily used for long-distance communication

4. They only operate at low frequencies

The correct answer is: The electric field is perpendicular to the Earth

Vertical antennas are designed in such a way that their radiating elements are oriented vertically, which results in the electric field being perpendicular to the Earth. This configuration allows for efficient radiation and reception of radio signals. The vertical orientation of the antenna helps to create a radiation pattern that can effectively propagate radio waves, especially at angles that are beneficial for communication over varying distances. This characteristic is particularly useful for certain types of communication, such as VHF and UHF, as well as for working with ground wave propagation, where effective communication can be achieved with low angles of radiation. The perpendicular electric field also contributes to stronger performance in specific applications and makes vertical antennas popular among amateur radio operators for various uses. While other aspects, such as operational frequency (not limited to low frequencies) and usage for long-distance communication (more effective for certain configurations and conditions), are relevant to antenna design and use, they do not specifically define the essential electrical phenomenon of how vertical antennas function regarding their electric field orientation relative to the Earth’s surface.