ARRL Technician Practice Exam

Why should the outer jacket of coaxial cable be resistant to ultraviolet light?

1. Ultraviolet light can damage the jacket and allow water to enter the cable

2. It enhances the cable's electrical conductivity

3. It prevents the cable from becoming too rigid

4. It improves the signal quality

The correct answer is: Ultraviolet light can damage the jacket and allow water to enter the cable

The outer jacket of coaxial cable is designed to be resistant to ultraviolet (UV) light primarily to protect the integrity of the cable. When coaxial cable is installed outdoors, it is exposed to varying environmental conditions, including UV radiation from sunlight. If the outer jacket is not resistant to UV light, prolonged exposure can lead to the degradation of the jacket material. This degradation can create cracks or other points of entry that allow moisture to penetrate the cable, potentially leading to performance issues, short circuits, or even complete failure of the cable. By ensuring that the outer jacket is UV resistant, manufacturers help to extend the life of the coaxial cable and maintain its functionality, especially in outdoor applications. The other options—enhancing electrical conductivity, preventing rigidity, and improving signal quality—do not specifically relate to the purpose of UV resistance of the outer jacket; rather, they pertain to other aspects of cable design and performance. Thus, the correct choice highlights the importance of environmental protection against UV damage in maintaining the durability and reliability of the cable.