Which of the following is NOT a characteristic of a digital signal?

• A. It has two states on and off.
• B. It is discrete.
• C. It is represented by a continuous range of voltages.
• D. It is a series of squares with high and low states.

Answer: (C)

Digital signals are defined by discrete levels that encode information in distinct states, usually seen as abrupt on/off transitions. They use specific voltage levels and change in steps, which creates square-shaped patterns with clear high and low states. An analog signal, on the other hand, carries information through a continuous range of voltages that can vary smoothly over time. That smooth, continuous range is what makes analog signals different from digital. So the statement describing a continuous range of voltages is not a digital characteristic. The other descriptions—two states on and off, being discrete, and appearing as a series of squares with high and low states—fit digital signals.