EDELMAN UNDERSTANDING ULTRASOUND PHYSICS EXAM
2025/2026 QUESTIONS WITH ANSWERS GRADED A+
✔✔The power of an ultrasound wave can be reported with which of the following units?
(More than one answer may be correct.)
a. Watts/square centimeter
b. dB/cm
c. Watts
d. kg/cm^2 - ✔✔Watts
✔✔Typically, as an ultrasound wave travels through soft tissue, the power of the wave :
a. Decreases
b. Increases
c. Remains the same - ✔✔Decreases
✔✔True or false. A sonographer can routinely change the power of a wave emitted by a
transducer used in diagnostic ultrasonic imaging. - ✔✔True
✔✔Mathematically, when a number is squared, the number is multiplied by :
a. 2
b. 0.5
c. Itself
d. 1.5 - ✔✔Itself
✔✔The final amplitude of an acoustic wave is reduced to one-half of its original value.
the final power is _________ the original power.
a. The same as
b. One-half
c. Double
d. None of the above - ✔✔None of the above
✔✔The amplitude of an acoustic wave decreases from 27 pascals to 9 pascals. If the
initial power in the wave was 27 watts, what is the wave's final power?
a. 3 watts
b. 9 watts
c. 1 watt
d. none of the above - ✔✔3 watts
✔✔The intensity of an ultrasound beam is defined as the ______ in a beam _________
by the _________ of the beam.
a. Power, multiplied, diameter
b. Amplitude, divided, area
c. Power, divided, area
d. Amplitude, multiplied, circumference - ✔✔Power, divided, area
,✔✔As sound travels in the body, what typically happens to the intensity of the wave?
a. Increases
b. Decreases
c. Remains the same - ✔✔Decreases
✔✔What are the units of intensity?
a. Watts
b. Watts/cm
c. Watts/cm^2
d. dB - ✔✔Watts/cm^2
✔✔True or false? With diagnostic ultrasonic imaging instruments, the operator can alter
the intensity of an ultrasonic beam produced by a transducer. - ✔✔True
✔✔What determines the initial intensity of an ultrasound beam?
a. The source of the soundwave
b. The medium through which the sound travels
c. Both A and B
d. Neither A nor B - ✔✔The source of the soundwave
✔✔What determines the intensity of an ultrasound beam after it has traveled through
the body?
a. The sound wave's source
b. The medium through which the sound travels
c. Both A and B
d. Neither A nor B - ✔✔Both A and B
✔✔What are the units of the transmitted intensity of a sound wave?
a. W/cm^2
b. Watts
c. dB
d. None; it is unitless - ✔✔W/cm^2
✔✔What happens when the power in an ultrasound beam is unchanged, and at the
same, the beam area doubles?
a. Doubles
b. Is halved
c. Is quartered
d. Remains the same - ✔✔Is halved
✔✔What happens to an acoustic beam's intensity when the power in the beam
increases by 25% while the cross-sectional area of the beam remains the same?
a. It increases by 25%
,b. It increased by 75%
c. It increases by 50%
d. Decreases by 25% - ✔✔It increases by 25%
✔✔When the power in an acoustic beam is doubled and the cross-sectional area of the
beam is halved, then the intensity of the beam is :
a. Doubled
b. Halved
c. Quartered
d. Four times larger - ✔✔Four times larger
✔✔What happens to the intensity of an ultrasound beam when the beam's cross-
sectional area remains unchanged while the amplitude of the wave triples?
a. It triples
b. Increases ninefold
c. Remains the same
d. None of the above - ✔✔Increased ninefold
✔✔If the power of the beam is tripled while the cross-sectional area of the beam
remains the same, the intensity ____________.
a. Triples
b. Increases ninfold
c. Remains the same
d. None of the above - ✔✔Triples
✔✔The amplitude of an acoustic wave is increased. Which of the following will most
likely remain unchanged? (More than one answer may be correct.)
a. Power
b. Frequency
c. Period
d. Intensity - ✔✔Frequency and period
✔✔A sonographer adjusts the output power of the wave emitted by the transducer.
Which of the following also changes? (More than one answer may be correct.)
a. Pulse repetition period
b. PRF
c. Propagation speed
d. Intensity - ✔✔Intensity
✔✔The wavelength of a cycle in an ultrasound wave can be reported with which units?
a. Units of time (sec, min, ect.)
b. Units of distance (feet,ect.)
c. Units of area (m^2, ect.)
d. Mm only - ✔✔Units of distance (feet,ect.)
, ✔✔The wavelength of an ultrasonic wave is determined by :
a. The sound source
b. The medium through which the wave travels
c. Both A and B
d. Neither A nor B - ✔✔Both A and B
✔✔What is the wavelength of 2 MHz sound in soft tissue?
a. 0.77 mm
b. Cannot be determined
c. 1.54 mm
d. 2 mm - ✔✔0.77 mm
✔✔Which of the following terms best describes the relationship between frequency and
wavelength for sound traveling in soft tissue?
a. Reciprocal
b. Direct
c. Related
d. Inverse - ✔✔Inverse
✔✔Two sound pulses travel through the same medium. One waves frequency is 2 MHz
and the other is 10 MHz. Which sound wave has a longer period?
a. The 10 MHz pulse
b. The 2 MHz pulse
c. Neither pulse
d. Cannot be determined - ✔✔The 2 MHz pulse
✔✔Two sound pulses travel through the same medium. One waves frequency is 2 MHz
and the other is 10 MHz. Which pulse has a longer wavelength?
a. The 10 MHz pulse
b. The 2 MHz pulse
c. Neither pulse
d. Cannot be determined - ✔✔The 2 MHz pulse
✔✔Two sound pulses travel through the same medium. One waves frequency is 2 MHz
and the other is 10 MHz. Which pulse has a lower propagation speed?
a. The 10 MHz pulse
b. The 2 MHz pulse
c. Neither pulse
d. Cannot be determined - ✔✔Neither pulse
✔✔Two sound pulses travel through the same medium. One waves frequency is 2 MHz
and the other is 10 MHz. Which pulse has the lowest power?
a. The 10 MHz pulse
2025/2026 QUESTIONS WITH ANSWERS GRADED A+
✔✔The power of an ultrasound wave can be reported with which of the following units?
(More than one answer may be correct.)
a. Watts/square centimeter
b. dB/cm
c. Watts
d. kg/cm^2 - ✔✔Watts
✔✔Typically, as an ultrasound wave travels through soft tissue, the power of the wave :
a. Decreases
b. Increases
c. Remains the same - ✔✔Decreases
✔✔True or false. A sonographer can routinely change the power of a wave emitted by a
transducer used in diagnostic ultrasonic imaging. - ✔✔True
✔✔Mathematically, when a number is squared, the number is multiplied by :
a. 2
b. 0.5
c. Itself
d. 1.5 - ✔✔Itself
✔✔The final amplitude of an acoustic wave is reduced to one-half of its original value.
the final power is _________ the original power.
a. The same as
b. One-half
c. Double
d. None of the above - ✔✔None of the above
✔✔The amplitude of an acoustic wave decreases from 27 pascals to 9 pascals. If the
initial power in the wave was 27 watts, what is the wave's final power?
a. 3 watts
b. 9 watts
c. 1 watt
d. none of the above - ✔✔3 watts
✔✔The intensity of an ultrasound beam is defined as the ______ in a beam _________
by the _________ of the beam.
a. Power, multiplied, diameter
b. Amplitude, divided, area
c. Power, divided, area
d. Amplitude, multiplied, circumference - ✔✔Power, divided, area
,✔✔As sound travels in the body, what typically happens to the intensity of the wave?
a. Increases
b. Decreases
c. Remains the same - ✔✔Decreases
✔✔What are the units of intensity?
a. Watts
b. Watts/cm
c. Watts/cm^2
d. dB - ✔✔Watts/cm^2
✔✔True or false? With diagnostic ultrasonic imaging instruments, the operator can alter
the intensity of an ultrasonic beam produced by a transducer. - ✔✔True
✔✔What determines the initial intensity of an ultrasound beam?
a. The source of the soundwave
b. The medium through which the sound travels
c. Both A and B
d. Neither A nor B - ✔✔The source of the soundwave
✔✔What determines the intensity of an ultrasound beam after it has traveled through
the body?
a. The sound wave's source
b. The medium through which the sound travels
c. Both A and B
d. Neither A nor B - ✔✔Both A and B
✔✔What are the units of the transmitted intensity of a sound wave?
a. W/cm^2
b. Watts
c. dB
d. None; it is unitless - ✔✔W/cm^2
✔✔What happens when the power in an ultrasound beam is unchanged, and at the
same, the beam area doubles?
a. Doubles
b. Is halved
c. Is quartered
d. Remains the same - ✔✔Is halved
✔✔What happens to an acoustic beam's intensity when the power in the beam
increases by 25% while the cross-sectional area of the beam remains the same?
a. It increases by 25%
,b. It increased by 75%
c. It increases by 50%
d. Decreases by 25% - ✔✔It increases by 25%
✔✔When the power in an acoustic beam is doubled and the cross-sectional area of the
beam is halved, then the intensity of the beam is :
a. Doubled
b. Halved
c. Quartered
d. Four times larger - ✔✔Four times larger
✔✔What happens to the intensity of an ultrasound beam when the beam's cross-
sectional area remains unchanged while the amplitude of the wave triples?
a. It triples
b. Increases ninefold
c. Remains the same
d. None of the above - ✔✔Increased ninefold
✔✔If the power of the beam is tripled while the cross-sectional area of the beam
remains the same, the intensity ____________.
a. Triples
b. Increases ninfold
c. Remains the same
d. None of the above - ✔✔Triples
✔✔The amplitude of an acoustic wave is increased. Which of the following will most
likely remain unchanged? (More than one answer may be correct.)
a. Power
b. Frequency
c. Period
d. Intensity - ✔✔Frequency and period
✔✔A sonographer adjusts the output power of the wave emitted by the transducer.
Which of the following also changes? (More than one answer may be correct.)
a. Pulse repetition period
b. PRF
c. Propagation speed
d. Intensity - ✔✔Intensity
✔✔The wavelength of a cycle in an ultrasound wave can be reported with which units?
a. Units of time (sec, min, ect.)
b. Units of distance (feet,ect.)
c. Units of area (m^2, ect.)
d. Mm only - ✔✔Units of distance (feet,ect.)
, ✔✔The wavelength of an ultrasonic wave is determined by :
a. The sound source
b. The medium through which the wave travels
c. Both A and B
d. Neither A nor B - ✔✔Both A and B
✔✔What is the wavelength of 2 MHz sound in soft tissue?
a. 0.77 mm
b. Cannot be determined
c. 1.54 mm
d. 2 mm - ✔✔0.77 mm
✔✔Which of the following terms best describes the relationship between frequency and
wavelength for sound traveling in soft tissue?
a. Reciprocal
b. Direct
c. Related
d. Inverse - ✔✔Inverse
✔✔Two sound pulses travel through the same medium. One waves frequency is 2 MHz
and the other is 10 MHz. Which sound wave has a longer period?
a. The 10 MHz pulse
b. The 2 MHz pulse
c. Neither pulse
d. Cannot be determined - ✔✔The 2 MHz pulse
✔✔Two sound pulses travel through the same medium. One waves frequency is 2 MHz
and the other is 10 MHz. Which pulse has a longer wavelength?
a. The 10 MHz pulse
b. The 2 MHz pulse
c. Neither pulse
d. Cannot be determined - ✔✔The 2 MHz pulse
✔✔Two sound pulses travel through the same medium. One waves frequency is 2 MHz
and the other is 10 MHz. Which pulse has a lower propagation speed?
a. The 10 MHz pulse
b. The 2 MHz pulse
c. Neither pulse
d. Cannot be determined - ✔✔Neither pulse
✔✔Two sound pulses travel through the same medium. One waves frequency is 2 MHz
and the other is 10 MHz. Which pulse has the lowest power?
a. The 10 MHz pulse
