Mid-term physics-quiz-1

Physics-1

Question #1: If a 2-Mhz frequency is used in human soft tissue, the wavelength is about


o.75 mm
0.15 mm
0.21 mm
0.44 mm



Question #2: A 10-dB difference in signal intensity is equivalent to


twofold of the original intensity
tenfold of the original intensity
hundredfold of original intensity
thousandfold of original intensity



Question #3: which of the following is the least obstacle (impedance) to the transmission of ultrasound?


muscle
fat
bone
blood



Question #4: Q factor refers to


the ratio of the operating frequency to the frequency bandwidth
the number of cycles per second
the range of highest frequency between lowest frequency in a pulse
he minimum distance of two points that scanner can distinguish



Question #5: Axial resolution is determined by which of the following


wavelength
Spatial pulse length
frequency
number of cycles in a pulse
all of above



Question #6: which of the following is least likely cause for attenuation?


absorption
reflection
refraction
scattering



Question #7: Diffraction refers to


spreading out of the ultrasound beam
conversion of sound to heat
redirection of a portion of the sound from a boundary beam
bending of the sound beam crossing a boundary



Question #8: when attempting to identify fetal heart motion, the frame rate of the real-time system should be


turned off to avoid confusion
set at a slow rate
set at a fast rate
set at five frames per second



Question #9: A transducer with a large bandwidth is likely to have


good axial resolution
a large ring-down time
poor resolution
a high Q factor



Question #10: High frequency transducers have


shorter wavelengths and less penetration
longer wavelengths and greater penetration
shorter wavelengths and greater penetration
longer wavelengths and less penetration