Physics Principles

Front 1

What best describes the ability of an object to resist compression and relates to the hardness of a medium?

Back 1

Stiffness

Front 2

An increase in pulse repetition frequency would lead to:

Back 2

Increase in Duty Factor

Front 3

Which of the following would have the highest propagation speed?
Air, Bone, Soft tissue, Water

Back 3

Bone

Front 4

Which of the following would have the lowest propagation speed?
Water, soft tissue, Bone, Lung tissue/

Back 4

Lung tissue

Front 5

As imaging depth increases, the pulse repetition frequency must:

Back 5

As imaging depth increases, the PRF decreases

Front 6

What describes the amount of refraction that occur at an interface?

Back 6

Refraction is a redirection of the transmitted sound beam

Front 7

Pressure is typically expressed in:

Back 7

Pressure is typically expressed in Pascals

Front 8

The typical range of frequency for diagnostic ultrasound imaging is:

Back 8

1 to 20 MHz

Front 9

9. The attenuatoin coefficient in soft tissue is equal to:

Back 9

One half of the frequency in soft tissue (f/2)

Front 10

10. Micro denotes:

Back 10

millionth

Front 11

11. Which of the following is described as the distance over which one cycle occurs?

Back 11

Wavelength

Front 12

12. All of the following are true of stiffness except:

Back 12

Stiffness and propagation speed are directly related: the stiffer the medium, the faster the propagation speed

Front 13

13. Areas of high pressure and density are referred to as:

Back 13

Compression

Front 14

14. Spatial pulse length can be calculated by:

Back 14

Spatial pulse length =
# of cycles in pulse x wavelength

Front 15

15. Density is typically measured in:

Back 15

Kilograms per centimeter cubed

Front 16

16. As a sound wave travels through the human body, the intensity of the sound wave decreases as a result of:

Back 16

Attentuation

Front 17

17. What is the total amount of attentuation that occurs if a 6.0 MHz sound beam travels through 4 cm of soft tissue?

Back 17

12 dB

Front 18

18. As imaging depth increases pulse repetition period:

Back 18

As imaging depth increases, the pulse repetition increases

Front 19

19. If pulse repetition frequency increases, then the duty factor:

Back 19

If the pulse repetition frequency increases, the duty factor increases

Front 20

20. The percentage of time that the ultrasound system is producing pulses of ultrasound describes the:

Back 20

Duty Factory

Front 21

21. Density and propagation speed are:

Back 21

Inversely related

Front 22

22. All of the following are true of power except:
-amplitude increases, power remains the same
-power is proportional to amp squared
-Intensity is proportional to power
-Power is measured in milliwatts

Back 22

Power decreases as amplitude decreases

Front 23

23. All of the following are true of wavelength except:
-It is determined by source and medium
-It is equal to period/frequency
-it is inversely related to freq
-It is directly related to period

Back 23

Wavelength = Propagation speed/Frequency

Front 24

24. Which of the following is determined by the sound source and medium?

Back 24

Wavelength

Front 25

25. Which of the following is defined as the number of ultrasound pulses emitted in 1 second?

Back 25

Pulse repetition Frequency

Front 26

26. Which of the following is defined as only the active time?

Back 26

Pulse Duration is only the active time or "on" time

Front 27

27. The inertia of the medium describes its:

Back 27

Density

Front 28

28. Which of the following is determined by the sound source only:
-Frequency
-Wavelength
-Spatial Pulse Length
-Propagation Speed

Back 28

Frequency

Front 29

29. The prefix "centi" denotes:

Back 29

Hundredths

Front 30

30. If the angle of incidence is 40, what is the angle of transmission at the interface if medium 1 has a prop speed of 1320 m/s and medium 2 has a prop speed of 1700 m/s?

Back 30

The angle of transmission is greater than 40

Front 31

31. The change in the direction of the original sound wave that occurs when sound interacts with two different tissue types that have a different propagation speed is referred to as:

Back 31

Refraction

Front 32

32. Which of the following is an appropriate unit of measurement for propagation speed?

Back 32

millimeters per microsecond

Front 33

33. The major component of attenuation is

Back 33

Absorption

Front 34

34. In clinical imaging, the wavelength measures between:

Back 34

0.1 and 0.8 mm

Front 35

35. The duty factor for continuous wave ultrasound is:

Back 35

100%

Front 36

36. All of the following relate to the strength of the sound wave except:
-Amplitude
-Wavelength
-Intensity
-Power

Back 36

Wavelength

Front 37

37. What is the change in intensity if the power decreases by half?

Back 37

Intensity is decreased by half

Front 38

38. Damping of the sound beam:

Back 38

Decreases spatial pulse length

Front 39

39. What is defined as the ability of the ultrasound system to image structures that are positioned parallel to the sound beam as separate structures?

Back 39

Axial resolution

Front 40

40. What is defined as the beginning of one pulse to the beginning of the next pulse, and therefore includes both the "on" and "off" time?

Back 40

Pulse repetition Period

Front 41

41. What is pressure measured in?

Back 41

Pascals or pounds per square inch

Front 42

42. What is essentially equal to the power of a wave divided by the area over which the power is distributed?

Back 42

Intensity = power of a wave/area over which power is distributed

Front 43

43. Transducers have material within them that, when electronically stimulated, produces ultrasound waves. This is mostly likely some form of:

Back 43

lead zirconate titonate

Front 44

44. What is the change in power if amplitude triples?

Back 44

power increases by 9 times

Front 45

45. The portion of the sound beam where molecules are pulled apart describes an area of:

Back 45

Rarefaction

Front 46

46. If only the density of a medium is increased then the:

Back 46

Propagation speed will decrease

Front 47

47. Sound is technically a:

Back 47

Mechanical and longitudinal wave

Front 48

48. The maximum value or minimum value of an acoustic variable minus the equilibrium value of that variable describes the:

Back 48

Amplitude

Front 49

49. Which of the following would be considered ultrasonic?
-10 Hz
-12.5 Hz
-1 MHz
-200 Hz

Back 49

1 MHz is an ultrasonic frequency

Front 50

50. Which of the following is considered the speed of sound in soft tissue?

Back 50

1540 m/s or 1.54 mm/us