Edelman: Comprehensive Exam
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
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
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
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 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
sound intensity is decreased by 75%. how many decibels of attenuation is this? -
CORRECT ANSWER-6 dB
the fundamental frequency of a transducer is 2.5 MHz. what is the second harmonic
frequency? - CORRECT ANSWER-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? -
CORRECT ANSWER-10cm
if a 5MHz sound wave is traveling in the tissues listed below, which will have the longest
wavelength? - CORRECT ANSWER-bone
if a 5MHz sound wave is traveling in the tissues listed below, which will have the
shortest wavelength? - CORRECT ANSWER-air
what is the approximate attenuation coefficient of 1MHz US in soft tissue? - CORRECT
ANSWER-0.5 dB/cm
the rayl is the unit of: - CORRECT ANSWER-impedance
impedance is the ________ of __________ and __________ - CORRECT ANSWER-
product, propagation speed, density
what are attenuation's three components? - CORRECT ANSWER-scattering, reflection,
absorption
for soft tissue, the approximate attenuation coefficient in dB/cm is equal to one-half
________ in ________ - CORRECT ANSWER-frequency, MHz
as the impedances of two media become vastly different, the ? - CORRECT ANSWER-
reflection increases
the angle between an US pulse and the boundary between two media is 90 degrees.
what is this called? - CORRECT ANSWER-orthogonal incidence
the angle between an US pulse and the boundary between two media is 56 degrees.
this is called: - CORRECT ANSWER-oblique incidence
refraction only occurs if there are: - CORRECT ANSWER-oblique incidence and
different propagation speeds
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
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
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
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 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
sound intensity is decreased by 75%. how many decibels of attenuation is this? -
CORRECT ANSWER-6 dB
the fundamental frequency of a transducer is 2.5 MHz. what is the second harmonic
frequency? - CORRECT ANSWER-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? -
CORRECT ANSWER-10cm
if a 5MHz sound wave is traveling in the tissues listed below, which will have the longest
wavelength? - CORRECT ANSWER-bone
if a 5MHz sound wave is traveling in the tissues listed below, which will have the
shortest wavelength? - CORRECT ANSWER-air
what is the approximate attenuation coefficient of 1MHz US in soft tissue? - CORRECT
ANSWER-0.5 dB/cm
the rayl is the unit of: - CORRECT ANSWER-impedance
impedance is the ________ of __________ and __________ - CORRECT ANSWER-
product, propagation speed, density
what are attenuation's three components? - CORRECT ANSWER-scattering, reflection,
absorption
for soft tissue, the approximate attenuation coefficient in dB/cm is equal to one-half
________ in ________ - CORRECT ANSWER-frequency, MHz
as the impedances of two media become vastly different, the ? - CORRECT ANSWER-
reflection increases
the angle between an US pulse and the boundary between two media is 90 degrees.
what is this called? - CORRECT ANSWER-orthogonal incidence
the angle between an US pulse and the boundary between two media is 56 degrees.
this is called: - CORRECT ANSWER-oblique incidence
refraction only occurs if there are: - CORRECT ANSWER-oblique incidence and
different propagation speeds
