Red Seal Electrician Practice
Signalling and communicationQuestion 135 of 1506

In the seven-layer model, which layer covers wire type, connector design and signal levels?

  1. Layer 1, the physical layer
  2. Layer 2, the data link layer
  3. Layer 4, the transport layer
  4. Layer 7, the application layer
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Correct answer: Layer 1, the physical layer

RS-232C only covers this first layer.

Source: Lessons in Electric Circuits IV: Digital (Kuphaldt), 14.7: Network Protocols

Practice signalling and communication

Questions last reviewed: 18 October 2026