Ultrasound Physics Chapter 6 Exam
Questions with Complete Solutions
sound waves weaken, or ________, as they travel through the body. - ANSWER-
attenuate
amplified - ANSWER-strengthened
deibel notation - ANSWER-standard measurement tool used to report the strength of
the wave
A number that represents the number of 10s that are multiplied to create the original
number - ANSWER-log
A simple way to determine the logarithm of an even power of ten is to - ANSWER-count
zeros
_____ is the common unit for measuring the strength of sound beams - ANSWER-
Decibel, dB
decibel notation is - ANSWER-logarithmic
Decibel notation does not measure absolute numbers, but reports ________
__________ - ANSWER-relative changes
Decibel notation is - ANSWER-a relative measurement,
a comparison,
a ration,
and logarithmic
decibels require two __________ - ANSWER-intensities
the two intensities are the ________ and the ________ level at the time of
measurement - ANSWER-reference, or starting point, and the actual level
positive decibels report signals that are - ANSWER-increasing
when a wave's intensity doubles, the relative change is - ANSWER-+3 decibels
when a wave's intensity increases 10-fold, the relative change is - ANSWER-+10
decibels
Negative decibels describe signals that are ___________ in strength - ANSWER-
decreasing
, when the intensity is reduced to half its original value, the relative change is -
ANSWER--3 decibels
when the intensity is reduced to 1/10 its original value, the relative change is -
ANSWER--10 decibels
As sound travels in the body, it weakens or ____________________ - ANSWER-
ATTENUATES
After a sound wave is received by the transducer, converted into electricity and returned
to the ultrasound system, it is strengthened or ________________ - ANSWER-
AMPLIFIED
Decibel Notation - ANSWER-A standard measurement tool used to report changes in
attenuation or amplification
- Does not measure absolute numbers, rather RELATIVE CHANGES
- LOGARITHMIC
Decibels (dB) - ANSWER-- are a way of quantifying/measuring:
1. the STRENGTH of sound beams as they travel through the body
2. the electrical SIGNAL strength
3. the BRIGHTNESS of images
Logarithm - ANSWER-Mathematical construct for rating numbers:
-The LOG represents the # of 10's that are multiplied to create the original number
- To determine the log of powers of ten, simply count the ZEROES
Decibels are Comparisons - ANSWER-This means that TWO intensities are required
1. the STARTING level
2. ACTUAL level at the time of measurement
Decibels are a Ratio - ANSWER-RATIO =
(Actual level / Starting level)
Positive Decibels - ANSWER-Report signals that are INCREASING in strength, or
GETTING LARGER
When a waves intensity is amplified by +3 dB - ANSWER-The intensity has increased
2X = DOUBLES
Amplified by +6 dB - ANSWER-The intensity has increased 4X = QUADRUPLED
Questions with Complete Solutions
sound waves weaken, or ________, as they travel through the body. - ANSWER-
attenuate
amplified - ANSWER-strengthened
deibel notation - ANSWER-standard measurement tool used to report the strength of
the wave
A number that represents the number of 10s that are multiplied to create the original
number - ANSWER-log
A simple way to determine the logarithm of an even power of ten is to - ANSWER-count
zeros
_____ is the common unit for measuring the strength of sound beams - ANSWER-
Decibel, dB
decibel notation is - ANSWER-logarithmic
Decibel notation does not measure absolute numbers, but reports ________
__________ - ANSWER-relative changes
Decibel notation is - ANSWER-a relative measurement,
a comparison,
a ration,
and logarithmic
decibels require two __________ - ANSWER-intensities
the two intensities are the ________ and the ________ level at the time of
measurement - ANSWER-reference, or starting point, and the actual level
positive decibels report signals that are - ANSWER-increasing
when a wave's intensity doubles, the relative change is - ANSWER-+3 decibels
when a wave's intensity increases 10-fold, the relative change is - ANSWER-+10
decibels
Negative decibels describe signals that are ___________ in strength - ANSWER-
decreasing
, when the intensity is reduced to half its original value, the relative change is -
ANSWER--3 decibels
when the intensity is reduced to 1/10 its original value, the relative change is -
ANSWER--10 decibels
As sound travels in the body, it weakens or ____________________ - ANSWER-
ATTENUATES
After a sound wave is received by the transducer, converted into electricity and returned
to the ultrasound system, it is strengthened or ________________ - ANSWER-
AMPLIFIED
Decibel Notation - ANSWER-A standard measurement tool used to report changes in
attenuation or amplification
- Does not measure absolute numbers, rather RELATIVE CHANGES
- LOGARITHMIC
Decibels (dB) - ANSWER-- are a way of quantifying/measuring:
1. the STRENGTH of sound beams as they travel through the body
2. the electrical SIGNAL strength
3. the BRIGHTNESS of images
Logarithm - ANSWER-Mathematical construct for rating numbers:
-The LOG represents the # of 10's that are multiplied to create the original number
- To determine the log of powers of ten, simply count the ZEROES
Decibels are Comparisons - ANSWER-This means that TWO intensities are required
1. the STARTING level
2. ACTUAL level at the time of measurement
Decibels are a Ratio - ANSWER-RATIO =
(Actual level / Starting level)
Positive Decibels - ANSWER-Report signals that are INCREASING in strength, or
GETTING LARGER
When a waves intensity is amplified by +3 dB - ANSWER-The intensity has increased
2X = DOUBLES
Amplified by +6 dB - ANSWER-The intensity has increased 4X = QUADRUPLED
