NASCLA Accredited Commercial General ContractorMechanical, Electrical, Plumbing (MEP)Hard

During the installation of a new data network in a commercial office, a contractor needs to ensure that the cabling infrastructure supports high-speed data transmission and is resistant to electromagnetic interference (EMI). Which type of twisted-pair cable would be most appropriate for this application?

  1. AUnshielded Twisted Pair (UTP) Category 5e
  2. BFiber Optic Cable Multimode
  3. CShielded Twisted Pair (STP) Category 6A
  4. DCoaxial Cable RG-6
Show answer & explanation

Correct answer: C. Shielded Twisted Pair (STP) Category 6A

Shielded Twisted Pair (STP) Category 6A cables offer superior performance for high-speed data (up to 10 Gigabit Ethernet) and excellent resistance to EMI due to their shielding, making them ideal for environments where EMI is a concern.

Why the other options are wrong

  • A. UTP Cat5e is less resistant to EMI and supports slower speeds (1 Gigabit Ethernet) than Cat6A.
  • B. Fiber optic cable is excellent for speed and EMI resistance but is not a 'twisted-pair' cable and is generally more expensive for horizontal runs within an office.
  • D. Coaxial cable is typically used for video or older network technologies, not modern high-speed data networks.

Shielded Twisted Pair (STP) Cable

A type of twisted-pair cable that includes an outer metallic foil or braid shield to protect the internal wire pairs from electromagnetic interference (EMI) and crosstalk, enhancing data integrity and speed.

  • Offers excellent EMI resistance.
  • Supports higher data rates over longer distances.
  • More expensive and harder to install than UTP.
  • Requires proper grounding for shielding to be effective.

Memory trick: Shielded Twists Stop Static, Speeding Data Safely.

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