1. Attenuation increases as distance _____.
2. Attenuation increases as frequency ______.
3. By definition, ultrasound is sound having a frequency greater than _____ cycles per second, that is, sound above the audible range.
4. Which of the following is not a property of acoustic waves?
- Pressure and particle velocity are in-phase.
- Particles in the medium oscillate with equal excursion in the positive and negative directions.
- The wave front is attenuated by converting the energy in the pressure wave to heat.
- There is movement of the material.
5. Which of the following types of tissue would have the lowest mean propagation velocity.
6. The ___ transducer and corresponding field of excitation excites molecules in the traditional “pie-shaped” field.
7. 1 atmosphere (14.7 psi) =
8. When c2>c1, total reflection can occur when the angle of incidence is ______ than the critical angle.
- Equal to
9. ______ is defined by the number of elements used (effective transducer width).
10. Which of the following is not a factor determining spatial resolution?
- Frequency (wavelength)
- Transmit intensity
- Pulse interval