The term duty factor is defined as:

The term duty factor is defined as:

• A. The fraction of time the transducer is actively transmitting sound
• B. The fraction of time the transducer is actively receiving sound
• C. The fraction of time between transmitted and received sound pulse
• D. The fraction of time between transmitted sound pulses

Answer: (A)

Duty factor is the fraction of time the transducer is actively transmitting during one ultrasound cycle. It’s calculated as the transmit (pulse) duration divided by the total cycle time (transmit plus listening). For example, if the pulse lasts 2 microseconds and the total cycle is 100 microseconds, the duty factor is 2/100 = 0.02, or 2%. This focuses on how much of the cycle the transducer is emitting, not on receiving or on the gap between pulses. Higher duty factor means more of the cycle is spent emitting, which affects average intensity and potential heating. The other options describe receiving time or the time between events, which are not what duty factor measures.

Duty factor is the fraction of time the transducer is actively transmitting during one ultrasound cycle. It’s calculated as the transmit (pulse) duration divided by the total cycle time (transmit plus listening). For example, if the pulse lasts 2 microseconds and the total cycle is 100 microseconds, the duty factor is 2/100 = 0.02, or 2%. This focuses on how much of the cycle the transducer is emitting, not on receiving or on the gap between pulses. Higher duty factor means more of the cycle is spent emitting, which affects average intensity and potential heating. The other options describe receiving time or the time between events, which are not what duty factor measures.