Duty cycle calculation from timing parameters A periodic digital waveform has pulse width tw = 6 ms and period T = 18 ms. Compute the duty cycle (%) = (tw / T) * 100.

Introduction / Context:
Duty cycle quantifies the fraction of time a digital signal stays HIGH within one period. It is crucial for pulse-width modulation (PWM), timing analysis, power electronics, and clocking strategies where average power or effective value depends on on-time ratio.

Given Data / Assumptions:

• Pulsed waveform with tw = 6 ms (HIGH time).
• Period T = 18 ms.
• Duty cycle D(%) = (tw / T) * 100.

Concept / Approach:
Use the definition directly, ensuring consistent units. Since both times are in milliseconds, unit conversion cancels out. Simplify the ratio and multiply by 100 to get a percentage.

Step-by-Step Solution:

Verification / Alternative check:
If the pulse is HIGH for 1/3 of the period and LOW for 2/3, average value of a 5 V signal would be about 1/3 * 5 ≈ 1.667 V, which is consistent with a 33.3% duty cycle interpretation in PWM systems.

Why Other Options Are Wrong:

• 3.3%: Off by a factor of 10 (likely decimal-place error).
• 6% or 18%: Confuses pulse width or period with percent; incorrect ratio.

Common Pitfalls:
Mixing milliseconds with seconds unnecessarily, or flipping the ratio T / tw. Always confirm that duty cycle is on-time divided by period.

Final Answer:
33.3%