To determine a duty factor, use a single pair of complete _______ and _______ times.

To determine a duty factor, use a single pair of complete _______ and _______ times.

• A. Wavelength, PRP
• B. Pulse duration, PRP
• C. Pulse duration, Period
• D. Period, Pulse repetition time

Answer: (B)

Duty factor is the fraction of time the ultrasound system is actively transmitting during one pulse repetition period. To determine it, you need two complete times from the same cycle: how long the pulse lasts (pulse duration) and the total time from the start of one pulse to the start of the next (pulse repetition period). Using those, duty factor = pulse duration divided by PRP. Wavelength isn’t involved because it relates to frequency and speed, not the on/off timing. The period alone is just the duration of one wave cycle and doesn’t account for the off time between pulses, so it wouldn’t give the true on-time relative to the full cycle. Therefore, the two times you use are pulse duration and PRP.

Duty factor is the fraction of time the ultrasound system is actively transmitting during one pulse repetition period. To determine it, you need two complete times from the same cycle: how long the pulse lasts (pulse duration) and the total time from the start of one pulse to the start of the next (pulse repetition period). Using those, duty factor = pulse duration divided by PRP. Wavelength isn’t involved because it relates to frequency and speed, not the on/off timing. The period alone is just the duration of one wave cycle and doesn’t account for the off time between pulses, so it wouldn’t give the true on-time relative to the full cycle. Therefore, the two times you use are pulse duration and PRP.