SPI ULTRASOUND PHYSICS- QUESTIONS PRACTICE EXAM|UPDATED&VERIFIED|GUARANTEED SUCCESS

What are the units of Wavelength? millimeters What are the units of Frequency? Hertz What are the units of Intensity? Watts/cm 2 What are the units of propagation speed? meters/sec What are the units of period? second power watts Wavelength is determine by ________. medium and sound source Frequency is determine by ________. sound source Intensity is determine by ________. sound source Propagation speed is determine by ________. medium Period is determine by ________. sound source Power is determine by ________. sound source Which parameters can be changed by the operator? Amplitude, intensity, power The power in the beam is 1 watt and the area is 5cm2. What is the beam's intensity? 0.2 w/cm2 If intensity remains the same while the power is doubled, what happens to beam area? doubled If frequency of sound is doubled, what happens to wavelength? Wavelength is halved. Pulse duration is the time from the start of a pulse to the end of that pulse. Pulse repetition period is the time from the start of a pulse to the start of the next pulse. Pulse repetition frequency is the reciprocal of pulse repetition period. When changing the imaging depth, which paramters dos the operator also changes? Pulse repetition frequency, duty factor, pulse repetition period. A signal's power increases from 1watt to 100 watts. How is this expressed in decibels? 20 dB The power of a system is at 100% and this is 0 dB. What is the dB change when the system's power is 50%? -3dB means half. The power of a system is at 100% and this is 0 dB. The system is changed to -6dB. What is the system's power? 25% power An ultrasound system is operating at 100% power and the power setting is 0dB. What would the power setting be when the system is operating at 10% power? -10dB