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19 Cards in this Set
- Front
- Back
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Perpendicular incidence is also known as
a. orthonganal incidence b. abnormal incidence c. oblique incidence d. rayleigh's incidence |
A
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The term derived from the product of the density and prop.speed of a medium is known as:
a. attenuation coefficient b. relection/refraction ratio c. impedence d. snell's law |
C
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The phenomenon that occurs when the beam strikes a small reflector with a diameter of less than the sound wavelength is reffered to as:
a. specular reflections b. rayleigh's scattering c. snells scattering d. none of the above |
B
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The angle of refraction is equal to the angle of incidence
true or false |
False
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the principle of refraction is known as:
a. Snell's Law b. Pouiselle's Law c. Bernoulli's equation d. ohm's law |
A
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If the prop. speed of a sound is greater in the second medium, the transmission angle will:
a. increase b. decrease c. remain the same |
A
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The factors that contribute to attenuation are:
a. scattering b. reflection c. absorption d. all of the above |
D
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As the stiffness of a medium increases the prop speed?
a. decreases b. increases c. remains the same |
B
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Which statement about higher frequencies is most correct?
a. attenuation decreased b. penetration increases c. does not affect the prop speed |
C
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The attenuation coefficient for soft tissue is equal to _____ dB/cm per MHz of frequency.
a. 3-5 b. 5-1.1 c. 1.1-2.0 d. 0.5-1.0 |
D
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Which trm is used to describe the interaction of sound with irregular shaped or rough edge structures?
a. attenuation b. absorption c. impedence d. scattering |
D
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The units for impedence are:
a. dB b. mm/microsec c. rayls d. no units |
C
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Which condition bewteen two media interfaces would produce the greatest amount of u/s reflected back to the transducer.
a. large impedence difference b. small impedence difference c. only angle of incidence afects reflection of us |
A
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in soft-tissue_____makes imaging less angle dependent.
a. refraction b. scattering c. absorption |
A
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Refraction often caused a type of artifact known as:
a. mirror image b. grating lobes c. lateral position error d. side lobes |
C
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The decibal notation is a convenient way to express the______between 2 intensities.
a. difference b. sum c. ratio d. product |
C
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Approx. what % of the sincident intensity is reflected at a soft tissue-air interface
a. 100% b. 50% to 75 % c. <20% d. 0% |
A
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attenuation coefficient is expressed in:
a. mW/cm2 b. dB/cm/MHz c. dB d. MHz/cm |
B
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in order for a refracted wave to be produced, which of the following conditions must be met at he interface?
a. oblique incidence, different sound speeds b. perpendicular incidence, same sound speed c. both of the sbove conditions produce refractions |
A
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