Which of the following causes failure of coaxial cables?

• A. Moisture contamination
• B. Excessive voltage
• C. Improper installation
• D. Thermal expansion

Answer: (A)

Moisture contamination can lead to the failure of coaxial cables because coaxial cables are designed to operate in a relatively stable environment. When moisture infiltrates the cable, it can cause several issues including signal degradation and corrosion of the conductors. This moisture can disrupt the insulation properties of the cable, leading to increased attenuation, shorts, or even complete failure of the cable over time. Additionally, moisture can mix with any contaminants already present in the cable, exacerbating the problem.

Excessive voltage, improper installation, and thermal expansion can also lead to issues with coaxial cables but are typically not as direct in causing failure as moisture contamination. For example, excessive voltage can lead to insulation breakdown, while improper installation can leave the cable susceptible to physical damage. Thermal expansion can affect the physical integrity of the cable but usually does not compromise its overall function unless combined with other factors. Therefore, moisture contamination stands out as a primary and frequent cause of failure in coaxial cables.