Which statement correctly identifies the data backbone distance for 100-ohm UTP?

Which statement correctly identifies the data backbone distance for 100-ohm UTP?

• A. 800 meters
• B. 90 meters
• C. 2000 meters
• D. 60,000 meters

Answer: (B)

When planning a copper cabling system, different parts of the network have different maximum lengths to keep signals clean and within standard limits. For 100-ohm UTP, the data backbone distance—the backbone run between telecommunications rooms—is specified as 90 meters. This limit is set so that, when you include the rest of the link (like horizontal runs and any patch cords in the work area), the total path length stays within the practical 100-meter ceiling commonly used for Ethernet. The extra 10 meters are typically consumed by patch cords and connections in the work area, so the backbone itself is capped at 90 meters. That’s why 90 meters is the correct choice. The other distances are far longer than what copper 100-ohm UTP can reliably support in standard backbone deployments.

When planning a copper cabling system, different parts of the network have different maximum lengths to keep signals clean and within standard limits. For 100-ohm UTP, the data backbone distance—the backbone run between telecommunications rooms—is specified as 90 meters. This limit is set so that, when you include the rest of the link (like horizontal runs and any patch cords in the work area), the total path length stays within the practical 100-meter ceiling commonly used for Ethernet. The extra 10 meters are typically consumed by patch cords and connections in the work area, so the backbone itself is capped at 90 meters. That’s why 90 meters is the correct choice. The other distances are far longer than what copper 100-ohm UTP can reliably support in standard backbone deployments.