ARDMS SPI EXAMINATION TEST PACK WITH
VERIFIED QUESTIONS AND FULL
◉ molecules of the medium vibrate at 90 degrees to the direction of
the traveling wave Answer: transverse wave
◉ what is the range of audible sound? Answer: 20 Hz to 20 kHz
◉ portion of a cycle where the molecules are pushed closer together
Answer: compression
◉ portion of a cycle where the molecules spread farther apart
Answer: rarefaction
◉ what are the three primary acoustic variables? Answer: pressure,
density, particle motion
◉ the time it takes for one cycle to occur Answer: period
◉ the number of cycles per second Answer: frequency
,◉ relationship between period and frequency Answer: inverse
◉ the speed at which sound travels through a medium Answer:
propagation speed (c)
◉ relationship between stiffness and propagation speed Answer:
direct
◉ "c" of soft tissue Answer: 1540 m/s or 1.54 mm/usec
◉ relationship between density, compressibility & elasticity to
propagation speed Answer: inverse
◉ length of a single cycle Answer: wavelength
◉ wavelength formula Answer: propagation speed/frequency
◉ max or min deviation of an acoustic variable from the average
value of that variable Answer: amplitude
◉ units of pressure amplitude Answer: pascals (Pa)
◉ the rate at which work is performed Answer: power
, ◉ how are power and amplitude proportioned? Answer: power =
amplitude squared
◉ intensity formula Answer: power/area (w/cm^2)
◉ resistance to the propagation of sound through a medium
Answer: impedance (z)
◉ units for impedance Answer: rayls
◉ what causes a strong reflection? Answer: 90 degree incidence and
strong impedance mismatch
◉ impedance formula Answer: z = density (p) x propagation speed
(c)
◉ sound waves are sent into the body and the returning wave is
timed to determine the reflectors distance from the transducer
Answer: pulse-echo technique
◉ most common element material Answer: lead zirconate titanate
(PZT)
VERIFIED QUESTIONS AND FULL
◉ molecules of the medium vibrate at 90 degrees to the direction of
the traveling wave Answer: transverse wave
◉ what is the range of audible sound? Answer: 20 Hz to 20 kHz
◉ portion of a cycle where the molecules are pushed closer together
Answer: compression
◉ portion of a cycle where the molecules spread farther apart
Answer: rarefaction
◉ what are the three primary acoustic variables? Answer: pressure,
density, particle motion
◉ the time it takes for one cycle to occur Answer: period
◉ the number of cycles per second Answer: frequency
,◉ relationship between period and frequency Answer: inverse
◉ the speed at which sound travels through a medium Answer:
propagation speed (c)
◉ relationship between stiffness and propagation speed Answer:
direct
◉ "c" of soft tissue Answer: 1540 m/s or 1.54 mm/usec
◉ relationship between density, compressibility & elasticity to
propagation speed Answer: inverse
◉ length of a single cycle Answer: wavelength
◉ wavelength formula Answer: propagation speed/frequency
◉ max or min deviation of an acoustic variable from the average
value of that variable Answer: amplitude
◉ units of pressure amplitude Answer: pascals (Pa)
◉ the rate at which work is performed Answer: power
, ◉ how are power and amplitude proportioned? Answer: power =
amplitude squared
◉ intensity formula Answer: power/area (w/cm^2)
◉ resistance to the propagation of sound through a medium
Answer: impedance (z)
◉ units for impedance Answer: rayls
◉ what causes a strong reflection? Answer: 90 degree incidence and
strong impedance mismatch
◉ impedance formula Answer: z = density (p) x propagation speed
(c)
◉ sound waves are sent into the body and the returning wave is
timed to determine the reflectors distance from the transducer
Answer: pulse-echo technique
◉ most common element material Answer: lead zirconate titanate
(PZT)
