ARRL Technician Practice Exam

What impact does signal polarity have in communication between stations?

1. It determines the frequency used

2. It affects the strength of received signals

3. It determines the type of equipment needed

4. It has no impact

The correct answer is: It affects the strength of received signals

The impact of signal polarity in communication between stations is significant because it does affect the strength of received signals. In radio communications, the polarity of a transmitted signal refers to the orientation of its electric field. For instance, signals can have vertical or horizontal polarization. When a transmitter's signal is polarized in one direction and the receiving antenna is oriented in a different direction, there can be a considerable reduction in the effective power of the received signal. This is due to the mismatch in polarization, which can lead to poorer antenna efficiency—meaning that the receiving antenna will not capture the signal as effectively. In contrast, when both transmitter and receiver use the same polarization, it allows for maximum signal strength and effective communication. Thus, understanding and properly matching the polarities of the transmitting and receiving equipment is crucial for optimizing communication quality and minimizing signal loss. The other options do not accurately reflect the influence of signal polarity. While frequency and equipment type can be essential considerations in communications, they are not directly governed by polarity. Additionally, saying that polarity has no impact overlooks its vital role in signal reception and quality.