ARRL Technician Practice Exam

Which of the following is a common use of coaxial cable?

1. Carrying RF signals between a radio and antenna

2. Transmitting data in telephone lines

3. Connecting computers to network switches

4. Powering remote devices

The correct answer is: Carrying RF signals between a radio and antenna

Coaxial cable is widely used in radio communications, specifically for carrying radio frequency (RF) signals between a radio transceiver and an antenna. This is due to its design, which includes an inner conductor surrounded by a dielectric insulator and an outer conductive shield. This construction provides excellent shielding against external interference and maintains a consistent impedance, which is critical for efficient signal transmission and minimizing loss. Using coaxial cable for RF signals allows for reduced signal degradation over distance compared to other types of cables, making it ideal for applications in amateur radio, television broadcasting, and various communication systems. The ability to effectively transmit and receive signals while minimizing noise is what makes coaxial cable the preferred choice for connecting radios to antennas. The other options refer to different technologies and cable types. For instance, telephone lines typically utilize twisted pair cables rather than coaxial cables for transmitting data. Similarly, connecting computers to network switches often involves Ethernet cables, which also do not employ the coaxial design. Finally, powering remote devices is usually accomplished through specific power cables or networking standards such as Power over Ethernet (PoE), rather than using coaxial cable, which is intended primarily for signal transmission.