Signalling and communicationQuestion 118 of 1506

What advantage does a digital signal have over an analog signal when electrical noise is present?

  1. It needs no wiring at all to carry the signal to the remote display
  2. It uses less power than any analog signal that is sent
  3. It cannot be affected by any interference of any size
  4. A very large interference is needed to turn an off signal into an on signal
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Correct answer: A very large interference is needed to turn an off signal into an on signal

Digital signals are either fully on or fully off.

Source: Lessons in Electric Circuits IV: Digital (Kuphaldt), 14.1: Introduction to Digital Communication

Practice signalling and communication

Questions last reviewed: 18 October 2026