Which of the following cable types is MOST commonly used for Ethernet networks in an office?
Cat5e supports Gigabit Ethernet and is widely used.
Why this answer
Cat5e (Category 5 enhanced) is the most common twisted-pair copper cable used in office Ethernet networks because it supports speeds up to 1 Gbps (1000BASE-T) over distances up to 100 meters, and it is backward-compatible with older 10/100 Mbps standards. Its widespread adoption, low cost, and ease of termination make it the default choice for structured cabling in modern office environments.
Exam trap
The trap here is that candidates often confuse 'most common for office Ethernet' with 'highest performance,' leading them to choose fiber optic (B) instead of recognizing that Cat5e is the practical, cost-effective standard for everyday office desktop connections.
How to eliminate wrong answers
Option A is wrong because coaxial cable (e.g., RG-6 or RG-59) is primarily used for cable television, broadband internet (DOCSIS), or legacy 10BASE2/10BASE5 Ethernet, not for modern office Ethernet networks. Option B is wrong because fiber optic cable, while capable of much higher speeds and longer distances, is more expensive and fragile to terminate, making it less common for general office desktop connections; it is typically reserved for backbone or data center links. Option C is wrong because USB (Universal Serial Bus) is a peripheral interface for connecting devices like keyboards, mice, and external storage, not a standard for Ethernet networking; while USB-to-Ethernet adapters exist, the cable itself is not used for Ethernet networks.