correct answers rated A+
Sound waves are: - correct answer ✔✔longitudinal, mechanical
The speed of sound in soft tissue is closest to: - correct answer ✔✔1,500 m/s
The frequency closest to the lower limit of ultrasound is: - correct answer ✔✔15,000 Hz
Which is not an acoustic variable? - correct answer ✔✔intensity
The effects of soft tissue on ultrasound are called: - correct answer ✔✔acoustic propagation properties
All of the following are true EXCEPT: - correct answer ✔✔two waves with identical frequencies must
interfere constructively
Put in decreasing order: deci, deca, micro, centi - correct answer ✔✔deca, deci, centi micro
______________ is the time to complete one cycle - correct answer ✔✔period
Which of the following sound waves is ultrasonic and least useful? - correct answer ✔✔30 KHz
What is the frequency of a wave with a 1 msec period? - correct answer ✔✔1 KHz
______________ is the distance covered by one cycle - correct answer ✔✔wavelength
Which of the following is determined by the source and the medium? - correct answer ✔✔range
resolution
,Propagation speed = ______________ x wavelength - correct answer ✔✔frequency
As a result of ______________, the propagation speed increases - correct answer ✔✔decreasing
compressibility and density
Put in decreasing order of propagation speed: gas, liquid, solid - correct answer ✔✔solid, liquid, gas
If the frequency of US is increased from 0.77 MHz to 1.54 MHz, what happens to the wavelength? -
correct answer ✔✔halved
A sound wave's frequency is 10 MHz. The wave is traveling in soft tissue. What is its wavelength? -
correct answer ✔✔.15 mm
If the frequency of an US wave is doubled, what happens to the period? - correct answer ✔✔halved
If the frequency of US is increased from 0.77MHz to 1.54MHz, what happens to the propagation speed? -
correct answer ✔✔remains the same
The units of PRF are: - correct answer ✔✔per minute
The time from the beginning of a pulse until its end is ______________? - correct answer ✔✔pulsed
duration
What happens to the speed of sound in a medium when the bulk modulus of the medium increases? -
correct answer ✔✔faster
___________ resolution is determined by SPL - correct answer ✔✔radial or axial
If a wave's amplitude is doubled, what happens to the power? - correct answer ✔✔quadrupled
, Power of sound has units of: - correct answer ✔✔watts
If the intensity of a sound beam remains unchanged while the beam area is reduced in half, what has
happened to the power? - correct answer ✔✔halved
Which of these intensities is the smallest? SATP, SPTP, SATA - correct answer ✔✔SATA
The duty factor for CW ultrasound is: - correct answer ✔✔1.0
What is the minimum value of the duty factor? - correct answer ✔✔0%
What are the units of intensity? - correct answer ✔✔watts/cm2
What happens to the speed of sound in a medium when the bulk modulus of the medium decreases? -
correct answer ✔✔slower
The units of attenuation are ______; this is a ______________ scale - correct answer ✔✔dB, logarithmic
Sound intensity is decreased by 75%. How many decibels of attenuation is that? - correct answer ✔✔6
dB
The fundamental frequency of a transducer is 2.5 MHz. What is the second harmonic frequency? -
correct answer ✔✔5 MHz
A pulse is emitted by a transducer and is traveling in soft tissue. The go-return-time, or time-of-flight, of
a sound pulse is 130 microseconds. What is the reflector depth? - correct answer ✔✔10 cm
If a 5 MHz sound wave is traveling in the tissues listed below, which will have the longest wavelength? -
correct answer ✔✔bone