Square wave characteristics: For an ideal square wave, what is the duty cycle (the percentage of one period that the signal remains HIGH)?

Introduction / Context:
Duty cycle quantifies how long a periodic signal stays in its active (HIGH) state within one full period. For timing, PWM, and digital logic analysis, recognizing duty cycle values is fundamental.

Given Data / Assumptions:

• “Square wave” implies equal HIGH and LOW durations.
• One period T = time HIGH + time LOW.
• Duty cycle (%) = (time HIGH / T) * 100.

Concept / Approach:
An ideal square wave has symmetrical mark and space times. Therefore, time HIGH equals time LOW, each being T/2, yielding a 50% duty cycle. Rectangular waves with unequal durations are not “square” but “pulse” or “rectangular” waves.

Step-by-Step Solution:

Verification / Alternative check:
Inspect a symmetric clock signal: the HIGH and LOW occupy equal horizontal spans on the oscilloscope; measurements across divisions confirm 50%.

Why Other Options Are Wrong:

Common Pitfalls:
Calling any periodic pulse “square.” Only the 50% case is strictly square. Be careful with definitions in specifications and timing diagrams.

Final Answer:
50%