DMSU 210 Physics Final Exam
Questions with 100% Correct
Answers
Which of the following is true about Pulse Duration?
a) It is affected by the number of cycles per pulse
b) It is the time from the start of one pulse to the start of the next
c) It includes both the transmit and listening time
d) It determines Spatial Pulse Length - Answer- a) It is affected by the number of cycles
per pulse
& d) It determines Spatial Pulse Length
Which frequency range represents infrasound?
a) 0-20 Hz
b) 20 Hz- 20 kHz
c) 2-10 MHZ
d) greater than 20 kHz - Answer- a) 0-20 Hz
Which of the following is NOT classified as an acoustic variable?
a) density
b) pressure
c) amplitude
d) particle motion - Answer- c) amplitude
Which terms describes the number of complete cycles per second in a sound wave?
a) Wavelength
b) Pulse Repetition Frequency (PRF)
c) Frequency
d) Period - Answer- c) Frequency
What factor has the greatest effect on propagation speed?
a) amplitude
b) frequency
c) medium stiffness
d) wavelength - Answer- c) medium stiffness
Which operator control affects image frame rate?
a)compression
b)transmit power
,c)scan depth
d)overall gain - Answer- c)scan depth
Which would be a potential source of noise in a real time image?
a)radiofrequency interference from electrical equipment
b)ultrasound waves from MRI scanners
c)X Rays from nearby radiographic rooms
d)Metal in a patient's clothes, jewelry, or body - Answer- a)radiofrequency interference
from electrical equipment
What terminology is used to describe changes in tissue that occur when sound waves
propagate?
a)Doppler effect
b)propagation speed
c)acoustic variables
d)pulse repetition frequency - Answer- c)acoustic variables
Which change may occur to a sound beam and result in an increase in absorption in
soft tissue?
a)an increase in propagation speed
b)a decrease is cycles per unit time
c)an increase in spatial pulse length
d)an increase in operating frequency - Answer- d)an increase in operating frequency
What law tells us at what angle a beam will be transmitted through a tissue interface?
a)Luez's Law
b)Doppler Law
c)Bernouilli's Law
d) Snell's Law - Answer- d)Snell's Law
What distinguishes color Doppler imaging from 2D grayscale imaging?
a)it uses multiple scan lines
b)it displays signal strength
c)it has range resolution
d)it averages pulse echoes - Answer- d)it averages pulse echoes
Which adjustment will result in an decrease in frame rate?
a)imaging at shallow depths
b)decreasing pulses per second
c)using fewer scan lines
d)decreasing field of view - Answer- b)decreasing pulses per second
What effect will occur from increasing frequency on a wide bandwidth multi-Hertz
transducer from 3.5 MHz to 5 MHz?
a)increased sound propagation speed
b)increased spatial pulse length
,c)increased penetration depth
d)decreased sound wavelength - Answer- d)decreased sound wavelength
An ultrasound wave traveling at 1540m/s in soft tissue is moving at a velocity equivalent
to which of the following?
a)154 mm/s
b)1540 mm/us
c)1.54 mm/us
d)154.0 m/s - Answer- c)1.54 mm/us
Directly related means that when a variable A increases, variable B:
a) remains the same
b) increases
c) decreases - Answer- B) increases
What are the common units representing 1,000 times?
a) Mega
b) Milli
c) Kilo
d) Giga - Answer- c) Kilo
15 MHz is equal to ________ Hz ?
a) 150,000
b) 15,000,000
c) 150,000,000,000
d) 1,500 - Answer- b) 15,000,000
When listening to audible sound, what is an indication of signal amplitude?
a) brightness
b) loudness
c) velocity
d) frequency - Answer- b) loudness
What is the period if frequency is 2 Hz?
a) 4 secs
b) 1/2 or 0.5 secs
c) 2 secs
d) 3 secs - Answer- b) 1/2 or 0.5 secs
What determines the propagation speed of a sound wave?
a) medium
b) wavelength
c) frequency
d) the tissue and the sonographer - Answer- a) medium!!!
If frequency changes by a factor of 2, what happens to propagation speed?
, a) it remains the same
b) it is reduced by -3 dB
c) it doubles
d) it is halved - Answer- a) it remains the same
Which frequency range represent ultrasound?
a) 20 Hz- 20 kHz
b) none of the above
c) 0-20 Hz
d) greater than 20 kHZ - Answer- d) greater than 20 kHz
If AMPLITUDE is increased by a factor of 2, what happens to POWER?
a) it increases by a factor of 4
b) it increases by a factor of 2
c) it increases by a factor of 9
d) it increases by a factor of 8 - Answer- a) it increases by a factor of 4
The Spatial Pulse Length (SPL) is dependent on: select all that apply
a) Frequency & Propagation speed
B) Frequency & number of cycles per pulse
c) amplitude & intensity
d) depth & PRF - Answer- a) Frequency & Propagation speed &
b) Frequency & number of cycles per pulse
Which of the following statements about Pulse Repetition Frequency (PRF) is correct?
a) PRF increases when imaging depth increases
b) PRF decreases when imaging depth increases
c) PRF is not affected by imaging depth
d) PRF is equal to Pulse Repetition Period (PRP) - Answer- b) PRF decreases when
imaging depth increases
True or False: The duty factor of continuous wave ultrasound system is typically less
than 1% - Answer- False
Which of the following changes when adjusting the image depth? (select all that apply)
a) PRP
b) PRF
c) Pulse Duration
d) Duty Factor - Answer- a) PRP, b) PRF, and d) Duty Factor
A system has a pulse repetition period (PRP) of 250 microseconds. What is the PRF?
a) 4 Hz
b) 400 Hz
c) 0.004 kHz
d) 4 kHz - Answer- d) 4 kHz
Questions with 100% Correct
Answers
Which of the following is true about Pulse Duration?
a) It is affected by the number of cycles per pulse
b) It is the time from the start of one pulse to the start of the next
c) It includes both the transmit and listening time
d) It determines Spatial Pulse Length - Answer- a) It is affected by the number of cycles
per pulse
& d) It determines Spatial Pulse Length
Which frequency range represents infrasound?
a) 0-20 Hz
b) 20 Hz- 20 kHz
c) 2-10 MHZ
d) greater than 20 kHz - Answer- a) 0-20 Hz
Which of the following is NOT classified as an acoustic variable?
a) density
b) pressure
c) amplitude
d) particle motion - Answer- c) amplitude
Which terms describes the number of complete cycles per second in a sound wave?
a) Wavelength
b) Pulse Repetition Frequency (PRF)
c) Frequency
d) Period - Answer- c) Frequency
What factor has the greatest effect on propagation speed?
a) amplitude
b) frequency
c) medium stiffness
d) wavelength - Answer- c) medium stiffness
Which operator control affects image frame rate?
a)compression
b)transmit power
,c)scan depth
d)overall gain - Answer- c)scan depth
Which would be a potential source of noise in a real time image?
a)radiofrequency interference from electrical equipment
b)ultrasound waves from MRI scanners
c)X Rays from nearby radiographic rooms
d)Metal in a patient's clothes, jewelry, or body - Answer- a)radiofrequency interference
from electrical equipment
What terminology is used to describe changes in tissue that occur when sound waves
propagate?
a)Doppler effect
b)propagation speed
c)acoustic variables
d)pulse repetition frequency - Answer- c)acoustic variables
Which change may occur to a sound beam and result in an increase in absorption in
soft tissue?
a)an increase in propagation speed
b)a decrease is cycles per unit time
c)an increase in spatial pulse length
d)an increase in operating frequency - Answer- d)an increase in operating frequency
What law tells us at what angle a beam will be transmitted through a tissue interface?
a)Luez's Law
b)Doppler Law
c)Bernouilli's Law
d) Snell's Law - Answer- d)Snell's Law
What distinguishes color Doppler imaging from 2D grayscale imaging?
a)it uses multiple scan lines
b)it displays signal strength
c)it has range resolution
d)it averages pulse echoes - Answer- d)it averages pulse echoes
Which adjustment will result in an decrease in frame rate?
a)imaging at shallow depths
b)decreasing pulses per second
c)using fewer scan lines
d)decreasing field of view - Answer- b)decreasing pulses per second
What effect will occur from increasing frequency on a wide bandwidth multi-Hertz
transducer from 3.5 MHz to 5 MHz?
a)increased sound propagation speed
b)increased spatial pulse length
,c)increased penetration depth
d)decreased sound wavelength - Answer- d)decreased sound wavelength
An ultrasound wave traveling at 1540m/s in soft tissue is moving at a velocity equivalent
to which of the following?
a)154 mm/s
b)1540 mm/us
c)1.54 mm/us
d)154.0 m/s - Answer- c)1.54 mm/us
Directly related means that when a variable A increases, variable B:
a) remains the same
b) increases
c) decreases - Answer- B) increases
What are the common units representing 1,000 times?
a) Mega
b) Milli
c) Kilo
d) Giga - Answer- c) Kilo
15 MHz is equal to ________ Hz ?
a) 150,000
b) 15,000,000
c) 150,000,000,000
d) 1,500 - Answer- b) 15,000,000
When listening to audible sound, what is an indication of signal amplitude?
a) brightness
b) loudness
c) velocity
d) frequency - Answer- b) loudness
What is the period if frequency is 2 Hz?
a) 4 secs
b) 1/2 or 0.5 secs
c) 2 secs
d) 3 secs - Answer- b) 1/2 or 0.5 secs
What determines the propagation speed of a sound wave?
a) medium
b) wavelength
c) frequency
d) the tissue and the sonographer - Answer- a) medium!!!
If frequency changes by a factor of 2, what happens to propagation speed?
, a) it remains the same
b) it is reduced by -3 dB
c) it doubles
d) it is halved - Answer- a) it remains the same
Which frequency range represent ultrasound?
a) 20 Hz- 20 kHz
b) none of the above
c) 0-20 Hz
d) greater than 20 kHZ - Answer- d) greater than 20 kHz
If AMPLITUDE is increased by a factor of 2, what happens to POWER?
a) it increases by a factor of 4
b) it increases by a factor of 2
c) it increases by a factor of 9
d) it increases by a factor of 8 - Answer- a) it increases by a factor of 4
The Spatial Pulse Length (SPL) is dependent on: select all that apply
a) Frequency & Propagation speed
B) Frequency & number of cycles per pulse
c) amplitude & intensity
d) depth & PRF - Answer- a) Frequency & Propagation speed &
b) Frequency & number of cycles per pulse
Which of the following statements about Pulse Repetition Frequency (PRF) is correct?
a) PRF increases when imaging depth increases
b) PRF decreases when imaging depth increases
c) PRF is not affected by imaging depth
d) PRF is equal to Pulse Repetition Period (PRP) - Answer- b) PRF decreases when
imaging depth increases
True or False: The duty factor of continuous wave ultrasound system is typically less
than 1% - Answer- False
Which of the following changes when adjusting the image depth? (select all that apply)
a) PRP
b) PRF
c) Pulse Duration
d) Duty Factor - Answer- a) PRP, b) PRF, and d) Duty Factor
A system has a pulse repetition period (PRP) of 250 microseconds. What is the PRF?
a) 4 Hz
b) 400 Hz
c) 0.004 kHz
d) 4 kHz - Answer- d) 4 kHz
