Which Connector Fits a Two-Pair Data Cable?

220-1201 By islever Editorial Last updated

Summarize basic cable types and their connectors, features, and purposes

Short answer

A Terminate the two-pair data cable with an RJ11 connector.

Question

A technician needs to replace the connector on a data cable that uses two pairs of wires. Which of the following connectors should the technician use?
  1. RJ11 Correct Answer
  2. F-type
  3. ST
  4. Molex

Key Takeaways

The question tests cable-to-connector matching by wire-pair count, and the trap is picking a connector that carries a different signal type (coax, fiber, or power) rather than a two-pair copper line.

This Core 1 question asks which connector terminates a data cable with two pairs (four) wires. The correct choice is the RJ11 connector, the standard modular plug for telephone-style two-pair cabling, while F-type, ST, and Molex serve entirely different media.

Common mistake: Learners often choose F-type because it appears on network-adjacent equipment, but F-type terminates coaxial cable with a single center conductor and shield, not two twisted pairs.

Expert Analysis

Why the Answer Is Correct

RJ11 is a small modular connector that seats four or six conductors, which matches a cable built with two wire pairs — the classic telephone/DSL wiring scheme. Because the question specifies exactly two pairs, RJ11 is the only listed connector designed to terminate that copper configuration, and it locks into the same modular jack used in analog phone and modem lines. A technician re-terminating such a cable would crimp a new RJ11 plug onto the sorted pair colors.

Why the Other Options Are Wrong

F-type is a threaded coaxial connector used for cable internet and CATV, carrying a single center conductor plus shielding rather than two pairs. ST (straight-tip) is a bayonet-style fiber-optic connector that terminates glass, not copper pairs. Molex is a legacy 4-pin peripheral power connector inside a computer chassis and has no role in data cabling.

Community Comment Notes

A commenter summarized the reasoning directly: "493. A — RJ11" with the note that "Two pairs/four wires commonly points to RJ11 telephone-style cabling." That matches the wire-count logic in the question, so the community reasoning and this analysis agree on option A.

Exam Strategy

Anchor on physical characteristics: count pairs or conductors, then match the connector family — modular copper (RJ11/RJ45), coaxial (F-type/BNC), fiber (ST/SC/LC), or power (Molex). Eliminate any connector that terminates a different media type before considering wire counts.

Frequently Asked Questions

Why isn't F-type the right connector for a two-pair data cable?

F-type is a coaxial connector with a single center conductor and shield, so it cannot terminate two twisted pairs of wires.

How many wires does an RJ11 connector support?

RJ11 seats four or six conductors, which covers the two-pair (four-wire) cabling described in the question.

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Discussion 2 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 2

  1. Afie 👍 1 Answered A
    RJ11 is a telephone/data connector that commonly uses two pairs of wires (4 wires). F-type is used for coaxial cable (cable TV/internet). ST is a fiber-optic connector. Molex is a power connector used inside computers.
  2. acf9805 👍 1 Answered A
    493. A — RJ11 🧸 Two pairs/four wires commonly points to RJ11 telephone-style cabling. ☎️

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