Systems Full Review Study Guide
sound waves are? - correct answer ✔✔ longitudinal, mechanical
the speed of US in soft tissue is closest to: - correct answer ✔✔ 1,500 m/s (1,540 m/s)
the frequency closest to the lower limit of US is: - correct answer ✔✔ 15,000 Hz
which is not an acoustic variable? - correct answer ✔✔ intensity
the effects of soft tissue on US are called: - correct answer ✔✔ acoustic propagation properties
all of the following are true except: - correct answer ✔✔ two waves with identical frequencies
must interfere constructively
put in decreasing order: - correct answer ✔✔ deca, deci, centi, micro
______________ is the time to complete one cycle - correct answer ✔✔ period
which of the following sound waves is ultrasonic and least useful in diagnostic imaging? - correct
answer ✔✔ 30 KHz
what is the frequency of a wave with 1msec period? - correct answer ✔✔ 1 kHz
_____________ is the distance covered by one cycle - correct answer ✔✔ wavelength
,Which of the following is determined by the source and the medium? - correct answer ✔✔
range resolution
propagation speed = ________ x wavelength - correct answer ✔✔ frequency
as a result of ____________ the propagation speed increases - correct answer ✔✔ decreasing
compressibility and decreasing density
put in decreasing order of propagation speed - correct answer ✔✔ solid, liquid, gas
if the frequency of US is increased from 0.77 MHz to 1.54 MHz, what happens to the
wavelength? - correct answer ✔✔ halved
a sound wave's frequency is 10MHz. the wave is traveling in soft tissue. what is its wavelength? -
correct answer ✔✔ 0.15 mm
if the frequency of an US wave is doubled, what happens to the period? - correct answer ✔✔
halved
if the frequency of US is increased from 0.77 MHz to 1.54 MHz, what happens to the
propagation speed? - correct answer ✔✔ remains the same
the units of pulse repetition frequency are? - correct answer ✔✔ per minute
the time from the beginning of a pulse until its end is __________? - correct answer ✔✔ pulse
duration
what happens to the speed of sound in a medium when the bulk modulus of the medium
increases? - correct answer ✔✔ faster
, ____________ resolution is determined by the spatial pulse length - correct answer ✔✔
axial/radial
if a wave's amplitude is doubled, what happens to the power? - correct answer ✔✔ quadrupled
if the level of an acoustic variable ranges from 55 to 105, what is the amplitude? - correct
answer ✔✔ 25
power of sound has units of? - correct answer ✔✔ watts
if the intensity of a sound beam remains unchanged while the beam area is reduced in half,
what has happened to the power? - correct answer ✔✔ halved
which of these intensities is smallest? - correct answer ✔✔ SATA
the duty factor for continuous wave ultrasound is? - correct answer ✔✔ 1
what is the minimum value of the duty factor? - correct answer ✔✔ 0.0%
what are the units of intensity? - correct answer ✔✔ watts/cm2
what happens to the speed of sound in a medium when the bulk modulus of the medium
decreases? - correct answer ✔✔ slower
the units of attenuation are _________; this is a ____________ scale. - correct answer ✔✔ dB,
logarithmic