🔍 Key Concepts

• Square wave signals alternate between two fixed voltage levels with very fast (nearly vertical) transitions. • In a square wave, the voltage stays constant (flat) for a time, then abruptly switches to the opposite level. • Compare the shapes: sine, sawtooth/triangular, and square all look distinct in how they rise, fall, and how long they stay at each level.

💭 Think About

• Which waveform in the illustration has long, flat sections at a constant voltage and then changes level almost straight up or straight down? • Which shapes can you eliminate because they steadily ramp up or down instead of holding a constant voltage? • Look for the waveform that spends equal time at a high level and a low level, with the transitions between them being nearly vertical.

✅ Before You Answer

• Verify that the correct choice has horizontal (flat) tops and bottoms, not sloping ones. • Confirm that the voltage only takes on two distinct levels (high and low) rather than smoothly varying through many values. • Eliminate any waveform that looks like a sine wave or a ramp/triangle and not like a digital on/off pattern.