What kind of wave does an oscilloscope produce?

• A. a DC square wave
• B. a DC sine wave
• C. an AC sine wave
• D. an AC square wave

Answer: (D)

An oscilloscope is a tool for visualizing how voltage changes over time. It doesn’t force a single waveform; instead it displays whatever signal is applied to it, letting you see how the voltage rises and falls, how long a pulse lasts, and how often it repeats. A square waveform that swings above and below zero (an AC square wave) is particularly informative because its sharp transitions make it easy to judge how fast the scope can resolve edges, measure period and duty cycle, and test bandwidth. A constant DC level wouldn’t show timing information, and a DC or AC sine wave, while possible to observe, doesn’t highlight the rapid transitions that demonstrate the scope’s time-domain capabilities as clearly. So, among the given options, an AC square wave best reflects what an oscilloscope is typically used to observe: a changing signal with fast edges.