Which type of cable has a minimum bend radius of 4 times its diameter?

Which type of cable has a minimum bend radius of 4 times its diameter?

• A. Backbone cable
• B. High-performance four-pair cable
• C. Optical Fiber cable
• D. Coaxial cable

Answer: (B)

Bend radius is how tightly you can curve a cable without harming its signal integrity. For high‑performance four‑pair copper cables used in fast Ethernet, the specification calls for a minimum bend radius of 4 times the cable diameter. This relatively tight but controlled bend helps keep the conductor geometry stable and preserves the cable’s impedance, reducing crosstalk and loss at high frequencies. Fiber optic cables, on the other hand, need much larger bend radii (often around 10x the diameter) because tight bends can cause significant attenuation in the glass. Coaxial and backbone cables typically follow different guidelines and usually don’t use this 4x rule for four‑pair copper. So the type that matches a minimum bend radius of 4 times its diameter is the high‑performance four‑pair copper cable.

Bend radius is how tightly you can curve a cable without harming its signal integrity. For high‑performance four‑pair copper cables used in fast Ethernet, the specification calls for a minimum bend radius of 4 times the cable diameter. This relatively tight but controlled bend helps keep the conductor geometry stable and preserves the cable’s impedance, reducing crosstalk and loss at high frequencies.

Fiber optic cables, on the other hand, need much larger bend radii (often around 10x the diameter) because tight bends can cause significant attenuation in the glass. Coaxial and backbone cables typically follow different guidelines and usually don’t use this 4x rule for four‑pair copper. So the type that matches a minimum bend radius of 4 times its diameter is the high‑performance four‑pair copper cable.