Chapters 1-4 Flashcards
Which of the following is described as the distance over which one cylce occurs?
wavelength
In diagnostic ultrasound period is in which units?
microsecond
What are the units for density
kg/cm³
Which of the following characteristics will create the fastest speed of sound?
a. Low density, low stiffness
b. High density, high stiffness
c. Low density, high stiffness
d. High density, low stiffness
c
Which of the following frequencies could be detected by the human ear?
a. 20 kHz
b. 2500 kHz
c. 25,000 Hz
d. 20 MHz
a
The frequency of the transducer is increased from 2.5 MHz to 10 MHz, what happened to the wavelength?
a. decreased to 1/4 the original wavelength
b. doubles
c. increased x 4
d. decreased to 1/2 the original wavelength
a
higher frequencies have shorter wavlengths.
The frequency did more than just double, so the wavelength has to be decreased by more the 1/2, which makes a the only logical answer
What happens to the speed of sound in a medium when the bulk modulus increases?
a. faster
b. slower
c. unchanged
a.
-bulk modulus is the same as stiffeness
Which of the following waves will have the shortest wavelength?
a. low frequency traveling in a fast medium
b. low frequency in a slow medium
c. high frequency in a fast medium
d. high frequency in a slow medium
d
speed and wavelength are directly related
sound in a slow medium=shorter wavelngth sound in a fast medium = longer wavelength
T or F If the power of a wave is halved, the intensity is reduced to one-fourth its original value.
F
power is proportional to intensity. if power is 1/2, intensity is 1/2
When changing the imaging depth, the sonographer also changes which parameters? (more than one can be correct)
a. PRF
b. duty factor
c. propagation speed
d. PRP
e. amplitude
f. SPL
a,b,d
A sonographer changes from a 3MHz transducer to a 6 MHz transduecer, but the imaging depth remains UNCHANGED what will happen to the following parameters
a. period
b. frequency
c. wavelength
d. speed
e. amplitude(initial)
f. power(initial)
g. intensity (initial)
h. PRF
i. PRP
a. period decreases
b. frequency increases
c. wavelength decreases
all the other paramerters remain the same
remember to change PRP, PRF or Duty factor I must change my DEPTH
To change my bigness parameters I need to change my output power. Changing my frequency alters how many cycles are happening in a given time frame which alters period frequency and wavelength
A sonographer increases the output power on a 3Mhz transducer in order to visualize a deeper structure. Only output power is adjusted, no other controlswere changed. What parameters will be changed?
Amplitude, Power, and Intensity.
(initial)
changing output power only affects the bigness parameters
bc we are changing the strength of the wave
True or false
Propagation speed does not change as frequency increases
True
Propagation speed and frequency are unrelated
True or false
A wave with a frequency of 150 Hz is audible
True
the time from the start of one pulse to the start of the next pulse
pulse repetition period
