📖 What is Coaxial Cable?
Coaxial cable transmits data via a central conductor surrounded by insulation and shielding, minimizing signal interference. Historically used for cable TV and 10BASE2 networks, it offers moderate bandwidth and is susceptible to signal degradation over long distances.
"Focus on its historical context and limitations. The exam often contrasts coaxial cable with modern cabling solutions like fiber optic and twisted-pair. Recognize its impedance (75 ohms) and common connectors (BNC, F-connector)."
📚 Certification: CompTIA Network+ Certification Exam (N10-009)
🔑 What are the Key Concepts of Coaxial Cable?
- ▸ Coaxial cable utilizes a central conductor and shielding to reduce electromagnetic interference, ensuring signal integrity during transmission.
- ▸ 75-ohm impedance is standard for video signals (like cable TV), while 50-ohm is used for data transmission – a common exam distinction.
- ▸ 10BASE2, an older Ethernet standard, employed coaxial cable with BNC connectors, but is rarely used in modern networks.
- ▸ Signal attenuation limits coaxial cable's practical distance; repeaters or amplifiers are needed for longer runs.
- ▸ Common connectors include BNC (older networks) and F-connectors (cable TV), and recognizing these is important for identification.
🎯 How does Coaxial Cable appear on the N10-009 Exam?
You may be asked to identify the cable type used in legacy networks, given a description of its physical characteristics and impedance.
A scenario might describe a network experiencing signal degradation over a long cable run – determine if coaxial cable is the likely culprit and suggest a solution.
Expect questions comparing and contrasting coaxial cable with twisted-pair and fiber optic cabling, focusing on bandwidth, distance, and cost.
❓ Frequently Asked Questions
Why is coaxial cable less common in modern networks?
Twisted-pair cabling offers higher bandwidth, lower cost, and easier installation. Fiber optic provides even greater bandwidth and distance capabilities, making coaxial cable largely obsolete for general networking.
What's the difference between 50-ohm and 75-ohm coaxial cable, and why does it matter?
50-ohm is typically used for data transmission, while 75-ohm is for video. Using the wrong impedance can cause signal reflections and degradation, impacting performance.
How does signal attenuation affect coaxial cable performance, and what can be done about it?
Attenuation weakens the signal over distance. Using repeaters or amplifiers boosts the signal, extending the cable's usable length, but adds complexity and cost.