In a pulse-width modulation system, what...

Question 1 of 27070cKnPoY9tUOHibEVR7AED

In a pulse-width modulation system, what parameter does the modulating signal vary?

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Question 1 of 27070

Q

In a pulse-width modulation system, what parameter does the modulating signal vary?

🔍 Key Concepts

• Pulse-width modulation (PWM) basic idea: how information is carried in rectangular pulses • Difference between amplitude, frequency, and width/duration of a pulse train • How a modulating (control) signal affects the shape of pulses over time

💭 Think About

• When you look at a PWM waveform on an oscilloscope, what aspect of each pulse is changing as the control signal goes up or down? • If the time between the start of one pulse and the next is fixed, which parameters cannot be changing? • Which choice corresponds to changing how long the pulse stays in the HIGH (on) state compared with the LOW (off) state within each period?

✅ Before You Answer

• Be clear on the difference between how tall a pulse is versus how long it lasts. • Consider whether PWM keeps the repetition rate (period/frequency) constant while varying something else. • Eliminate answers that would describe pulse-height modulation or frequency modulation, not PWM.