List these metric terms in increasing order: mega, micro, hector, deca, deci, milli
Micro, milli, deci, deca, hector, mega
100
What units are used to report the pressure of a sound beam?
Pascals
100
Intensity is measured in units of....
Watts/cm^2
100
A sound pulse travels in Medium 1 and strikes an interface with another tissue, Medium 2 at 30 degrees. The angle of transmission is 10 degrees. In which medium is the impedance higher?
Can not be determined.
100
The matching layer has an impedance between
____ and the skin.
PZT
200
What do waves transfer from one location to the other?
Energy
200
Of the four waves whose periods are listed below, which has the highest frequency?
-8s
-8us
-8ms
-800ks
80us
200
What is the log of 10,000?
4
200
What property has units of rayls?
Impedance
200
PZT is equal to _____ wavelength.
1/2
300
What is not true of sound waves?
-they are acoustic
-they are pressure waves
-they are transverse
-they move energy
They are transverse
300
What are the units of wavelength?
Millimeters
300
Attenuation in lung tissue is _____ as the attenuation in soft tissue.
Greater than
300
If the initial intensity of a sound beam is less than the final intensity, then the gain in dB is
Positive
300
The impedance of a transducer active element is 1,900,000 rayls and the impedance of skin is 1,400,000 rayls. What is the acceptable impedance for the matching layer?
-1,726,000 -1,200,000
-1,400,000 -1,950,000
1,726,000 Rayls
400
Which of the following describes sound waves the best?
-transverse, pressure waves
-transverse, longitudinal waves
-longitudinal, out-of-phase waves
-longitudinal, pressure waves
Longitudinal, pressure waves
400
True or False. Propagation speed increases as frequency increases.
False
400
What are the units of attenuation?
dB
400
Every 10 dB change means that the intensity will
Increase 10 times
400
Which of the following probes creates a beam with the most divergence?
-4 mm diameter, 4 MHz
-5 mm diameter, 8 MHz
-6 mm diameter, 8 MHz
-4 mm diameter, 2 MHz
4 mm diameter, 2 MHz
500
Two waves are traveling in a medium and arrive at a location at the same time. What event takes place?
Interference
500
What is the effects of sound waves on the body called?
Bio-effects
500
A pulse of ultrasound propagates in soft tissue, such as liver. The pulse strikes a soft tissue-soft tissue interface with oblique incidence. Some of the sound energy is transmitted. Does significant refraction occur?
No.
500
The maximum imaging depth during an ultrasound is 10 cm. The sonographer adjusts the imaging depth to 20 cm. What happens to the PRP?
It is doubled.
500
A small piece of PZT creates a sound beam that is V-shaped. This is also called: