US Physics 121-150

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US Physics 121-150
2013-06-20 01:48:58

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  1. What term refers to regions of decreased particle density in sound beam?
  2. 10-³ equals:
  3. Which of the following represents the number 1234 in scientific notation?

  4. One MHz equals:
    10(six) HZ
  5. Terms used to describe the strength of the sound beam include:
    Amplitude and intensity
  6. You are imaging with a 5 MHz linear array transducers. What sound parameter stays constant as the beam propagates through the tissue?
    Frequency, Intensity, Amplitude or Wavelength ( None of the above)
  7. Ultrasound propagation velocity depends on:
    Density and compressibility
  8. You notice that the image in the far field is less bright compared to the near field. This is due to:
    Sound attenuation
  9. Acoustic impedance:
    Equals density times the propagation speed
  10. What determines the speed of sound?
    Medium through which sound wave passes
  11. You will NOT see refraction in the sonographic image if:
    The sound beam is perpendicular to the interface
  12. The rate of sound attenuation is lowest in:
  13. When you perform a Doppler exam, the frequency of the transmitted signal is determined by:
    The frequency if the electrical signal applied to the transducer
  14. Power divided by the beam area is equal to the:
  15. Axial resolution is determined chiefly by:
    Pulse duration
  16. Choose two benefits of tissue harmonic imaging
    Grating lobe artifacts are reduced and lateral resolution is improved
  17. Acoustic impedance increases with which of the following:
    Increased tissue density and increased propagation speed
  18. When you adjust the pulse repetition frequency, you are changing:
    The number of pulses per second
  19. Which of the following would increase the spatial pulsed length?
    Increased number of cycles per pulse
  20. Doppler pulses used for diagnostic purposes are typically __ cycles long?
  21. The time that it takes for one pulse to occur is known as the:
    Pulse duration
  22. The length of space over which one cycle occurs is known as the:
  23. Bandwidth refers to:
    Range of frequencies in a pulse
  24. When sound strikes a specular reflector at an oblique angle, the angle of reflection is:
    Equal to but opposite the angle of incidence
  25. Which describes constructive interference?
    Sound waves are in phase and resulting amplitude is increased

  26. The dark area indicated by the arrow in this image is primarily due to:
    Increased attenuation
  27. Which sound beam frequency would exhibit the greatest intensity loss with increasing depth?
    10 MHz
  28. Interference patterns of reflected waves causes:
    Acoustic speckle
  29. Attenuation of the sound beam is affected by:
    Absorption, Scattering and Reflection
  30. The transfer of acoustic energy into heat is termed: