sound waves are? - Answers longitudinal, mechanical
the speed of US in soft tissue is closest to: - Answers 1,500 m/s (1,540 m/s)
the frequency closest to the lower limit of US is: - Answers 15,000 Hz
which is not an acoustic variable? - Answers intensity
the effects of soft tissue on US are called: - Answers acoustic propagation properties
all of the following are true except: - Answers two waves with identical frequencies must
interfere constructively
put in decreasing order: - Answers deca, deci, centi, micro
______________ is the time to complete one cycle - Answers period
which of the following sound waves is ultrasonic and least useful in diagnostic imaging? -
Answers 30 KHz
what is the frequency of a wave with 1msec period? - Answers 1 kHz
_____________ is the distance covered by one cycle - Answers wavelength
Which of the following is determined by the source and the medium? - Answers range resolution
propagation speed = ________ x wavelength - Answers frequency
as a result of ____________ the propagation speed increases - Answers decreasing
compressibility and decreasing density
put in decreasing order of propagation speed - Answers solid, liquid, gas
if the frequency of US is increased from 0.77 MHz to 1.54 MHz, what happens to the wavelength?
- Answers halved
a sound wave's frequency is 10MHz. the wave is traveling in soft tissue. what is its wavelength?
- Answers 0.15 mm
if the frequency of an US wave is doubled, what happens to the period? - Answers halved
if the frequency of US is increased from 0.77 MHz to 1.54 MHz, what happens to the
propagation speed? - Answers remains the same
the units of pulse repetition frequency are? - Answers per minute
, the time from the beginning of a pulse until its end is __________? - Answers pulse duration
what happens to the speed of sound in a medium when the bulk modulus of the medium
increases? - Answers faster
____________ resolution is determined by the spatial pulse length - Answers axial/radial
if a wave's amplitude is doubled, what happens to the power? - Answers quadrupled
if the level of an acoustic variable ranges from 55 to 105, what is the amplitude? - Answers 25
power of sound has units of? - Answers watts
if the intensity of a sound beam remains unchanged while the beam area is reduced in half,
what has happened to the power? - Answers halved
which of these intensities is smallest? - Answers SATA
the duty factor for continuous wave ultrasound is? - Answers 1
what is the minimum value of the duty factor? - Answers 0.0%
what are the units of intensity? - Answers watts/cm2
what happens to the speed of sound in a medium when the bulk modulus of the medium
decreases? - Answers slower
the units of attenuation are _________; this is a ____________ scale. - Answers dB, logarithmic
sound intensity is decreased by 75%. how many decibels of attenuation is this? - Answers 6 dB
the fundamental frequency of a transducer is 2.5 MHz. what is the second harmonic frequency?
- Answers 5 MHz
a pulse is emitted by a transducer and is traveling in soft tissue. the go-return time, or time of
flight, of a sound pulse is 130 microseconds. what is the reflector depth? - Answers 10cm
if a 5MHz sound wave is traveling in the tissues listed below, which will have the longest
wavelength? - Answers bone
if a 5MHz sound wave is traveling in the tissues listed below, which will have the shortest
wavelength? - Answers air
what is the approximate attenuation coefficient of 1MHz US in soft tissue? - Answers 0.5 dB/cm
the rayl is the unit of: - Answers impedance
impedance is the ________ of __________ and __________ - Answers product, propagation speed,
density