Final Flashcards
What do waves transfer from one location to another/
Energy
Which of the following terms does not belong?
A. compression
B. region of high density
C. region of high pressure
D. wide molecular spacing
D
Variations in all of the following identify specific waves as acoustic waves except:
Pressure
Parameters
Density
Acoustic variables
parameters
What kind of waves are soundwaves?
mechanical, longitudinal, pressure waves
All of the following are acoustic parameters except:
Pressure
Period
Propagation speed
Frequency
Pressure
Which types of waves will exhibit both constructive and destructive interefence?
A. waves of different amplitude
B. a pair of longitudinal waves
C. waves of different frequency
D. out of phase waves
C
What units are used to report the pressure of a sound beam?
pascals
Which of the following waves is infrasonic?
4 MHz
400 kHz
28 Hz
2 Hz
2 Hz, below 20=infra
Which wave is ultrasonic?
400 mHz
4 MHz
28 Hz
2 Hz
4 MHz, greater than 20,000=ultra
Which of these is ultrasonic and most useful diagnostically?
400 MHz
4 MHz
2 kHz
200,000 Hz
4 MHz
Identify all waves that are inaudible
4 MHz
400 kHz
28 Hz
2 Hz
4 MHz, 400 kHz, 2 Hz
Which of the following waves has the longest period?
2 MHz
4,000 Hz
6 Hz
1 kHz
6 Hz
Of the four waves whose periods are listed below, which has the highest frequency?
8 s
80 microseconds
8 Ms
800 ks
80 microseconds
Of the four waves whose frequencies are listed below, which has the shortest period?
12 kHz
6,000 Hz
205 Hz
1 kHz
12 kHz
What parameter is determined by both the source and the medium?
wavelength
What two characteristics of a medium determine the speed of sound?
stiffness and density
increased stiffness = increased speed
increased density = decreased speed
T or F: If the amplitude of a wave is increased to 3 times its original value, the intensity is increased by 6 times.
False, intensity is proportional to amplitude squared, intensity would increase by a factor of 9
T or F: If the power of a wave is halved, the intensity is reduced to 1/4 is original value
False, if power is halved, intensity is halved
T or F: Propagation speed increases as frequency increases
False
Medium 1 has a density of 9 and a stiffness of 6. Medium 2 has a density of 8 and a stiffness of 6. In which medium will sound travel slower?
Medium 1
If the power in a beam is 1 watt and the area is 5 sq cm, what is the beam’s intensity?
5 W/sq cm
1 W/sq cm
0.2 W/sq cm
1 Watt
0.2 W/cm sq
If intensity remains the same while the power is doubled, what has happened to the beam area?
A. quadrupled
B. doubled
C. halved
D. unchanged
B
A sound beam travels a total of 10 cm in 2 seconds. What is the speed of the sound?
A. 10 cm/sec
B. 2 cm/sec
C. 5 cm/sec
D. 0.2 cm/sec
C. 10 cm/2 s = 5 cm/s
T or F: Propagation speed increases as frequency increases
False
T or F: Propagation speed increases as frequency decreases
False
T or F: Propagation speed does not change as frequency increases
True
What is the wavelength of 3 MHz sound in soft tissue?
A. 0.51 m
B. 0.51 km
C. 0.51 mm
D. 0.51 nm
E. 0.51 micrometers
C
What is the wavelength of 2 MHz sound in soft tissue?
A. 1.54 mm
B. 0.77 mm
C. 0.51 mm
D. 1.54 km/s
E. 3.08 mm
B.
1.54/2 MHz = 0.77
Which of the following are considered acoustic variables?
A. frequency
B. density
C. particle motion
D. temperature
E. period
F. pressure
B, C, F
Which of the following are considered acoustic parameters?
A. frequency
B. density
C. distance
D. pressure
E. period
A, E
The effects of tissue on sound waves are called
acoustic propagation properties
Which of these values for PRF would have the longest PRP?
A. 2 kHz
B. 4,000 Hz
C. 6 Hz
D. 1 kHz
C
Which of the following four waves has the highest PRF based on PRP?
A. 8 s
B. 80 ms
C. 5 ms
D. 400 ks
C
Which of these pulses with PRF listed below has the shortest PRP?
A. 12 kHz
B. 6000 Hz
C. 20 kHz
D. 1 kHz
C
Four waves have PRPs as listed. Which wave has the lowest PRF?
A. 8 s
B. 80 microseconds
C. 8000 ns
D. 800 ms
A
T or F: Two waves can have identical PRFs, even if their PRPs are different
False
T or F: Two waves can have identical PRFs even if their periods are different
True
T or F: Two waves can have identical PRFs, even if their frequencies are different
True
T or F: PRF and PRP are determined only by imaging depth.
True
If all other factors remain unchanged, what happens to duty factor when the PRF increases?
increases
If all other factors remain unchanged, what happens to the duty factor when imaging depth increases?
Decreases
If all other factors remain the same, what happens to the duty factor when the PRP increases?
Decreases
If all other factors remain unchanged, what happens to the duty factor when the sonographer uses a new transducer with a longer pulse duration?
increases
What is the duty factor if the pulse duration is 1 microsecond and the PRP is 1 ms?
A. 100%
B. 0.1
C. 0.01
D. 0.001
D
Which of the following terms does not belong?
A. high duty factor
B. shallow imaging
C. low PRF
D. short PRP
C
