Difficulty: Easy
Correct Answer: 33.3%
Explanation:
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:
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:
Form ratio: tw / T = 6 / 18.Simplify: 6 / 18 = 1 / 3 ≈ 0.3333.Convert to percent: 0.3333 * 100 = 33.33…%.Rounded to listed choice: 33.3%.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:
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%
Discussion & Comments