3.1 - Cables and connectors

CompTIA A+ Core 1 objective 3.1 covers identifying cables and connectors. HDMI carries both video and audio digitally and is standard on modern displays. USB Type-C is a small reversible connector that can carry data, video and power on many devices. RJ45 is the connector used to plug a wired network cable into a PC. You should also know USB speeds - for example, USB 3.2 Gen 2 offers roughly 10 Gbps - and recognise DisplayPort, Thunderbolt and legacy connectors. Expect scenario questions that describe a need - carry video and audio, a reversible do-everything port, wired networking, a given speed - and ask which cable or connector matches, or ask you to identify one from a description. Being able to name a connector from a photo is a common Core 1 task.

Memory hook
Video + audio, digital = HDMI. Reversible data/video/power = USB-C. Wired network plug = RJ45. ~10 Gbps USB = USB 3.2 Gen 2.

Practice questions

1. What is the maximum data rate of USB 2.0?

  • 12 Mbps
  • 100 Mbps
  • 480 Mbps (correct answer)
  • 5 Gbps

USB 2.0 (High Speed) tops out at 480 Mbps. USB 3.0/3.2 Gen 1 is 5 Gbps and higher.

2. Which device lets one keyboard, monitor and mouse control multiple computers?

  • Docking station
  • Hub
  • KVM switch (correct answer)
  • Repeater

A KVM (Keyboard, Video, Mouse) switch shares one set of peripherals across several PCs.

3. A monitor is described as 2560x1440 @ 144 Hz. What does 144 Hz refer to?

  • The screen's overall pixel density
  • The color bit depth of the display panel
  • The refresh rate in frames per second (correct answer)
  • The panel's gray-to-gray response time

Refresh rate is how many times per second the screen redraws; 144 Hz = up to 144 fps, smoother motion.

4. Which cable carries digital video AND audio over a single connector?

  • VGA
  • HDMI (correct answer)
  • PS/2
  • RJ45

HDMI (and DisplayPort) carry digital video and audio together. VGA is analog video only.

5. Which interface allows hot-swappable EXTERNAL drives at SATA speeds?

  • PS/2
  • eSATA (correct answer)
  • VGA
  • PCIe

eSATA extends SATA to external, hot-swappable drives. (USB and Thunderbolt are common alternatives.)

6. Which interface supports daisy-chaining displays and high-speed data, often using a USB-C connector?

  • A legacy VGA video connector
  • A Thunderbolt interface (correct answer)
  • A legacy PS/2 connector
  • A telephone RJ11 connector

Thunderbolt 3/4 (USB-C) carries data, video (DisplayPort) and power, and supports daisy-chaining devices.

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