Describing Sound Waves - Period & Frequency

Question 1

Describes the features of a sound wave

Answer 1

Parameters

Question 2

The ______ of a sound wave is the ultrasound system and transducer.

Answer 2

Source

Question 3

The quantity, or level, of some of the parameters are established by the…

Answer 3

Ultrasound system

Question 4

Other parameters are determined by the tissue through which the sound is traveling. This tissue is called the…

Answer 4

Medium

Question 5

The time it takes a wave to vibrate a single cycle, or the time from the start of one cycle to the start of the next cycle.

Answer 5

Period

Question 6

Period is reported in ____of time, such as microseconds, seconds, hours, or days.

Answer 6

Units

Question 7

The typical value of a period in diagnostic ultrasound is…

Answer 7

0.06 to 0.5 μs

Question 8

Period is determined by the _______ only, not by the medium.

Answer 8

Sound source

Question 9

True or False? The period can be changed while using a basic ultrasound system with a particular transducer.

Answer 9

False

Question 10

The number of particular events that occur in a specific duration of time…

Answer 10

Frequency

Question 11

In diagnostic ultrasound, the frequency of a wave is described as the number of ______ that occurs in one second.

Answer 11

Cycles

Question 12

Frequency is reported in units of …

Answer 12

Per second, 1/second, hertz (Hz) (another way to say “per second”

Question 13

In clinical imaging, frequency ranges from approximately…

Answer 13

2 MHz to 15 MHz (or 2 million to 15 million per second)

Question 14

Frequency of a sound wave is determined by the _______ only.

Answer 14

Sound source

Question 15

True or False? The sonographer cannot change the frequency while using a basic ultrasound system and transducer.

Answer 15

True

Question 16

Infrasound (infrasonic) frequency

Answer 16

Less than 20 Hz

Question 17

Audible sound frequency range

Answer 17

Between 20 Hz and 20 kHz

Question 18

Ultrasound (ultrasonic) frequency range

Answer 18

Greater than 20 kHz

Question 19

Frequency in ultrasound is important because it affects _______ and image ______.

Answer 19

Penetration, quality

Question 20

Period and frequency are _______ related to each other.

Answer 20

Inversely

Question 21

As frequency increase, period ______.
As frequency decreases, period ______.
If one of these parameters remains constant, then the other remains _______.

Answer 21

Decreases, increases, unchanged

Question 22

Period and frequency have an even more special relationship called…:

Answer 22

Reciprocal

Question 23

When two reciprocal parameters are multiples together, the result is…

Answer 23

1

Question 24

What is the period of the earth’s rotation around the sun?

Answer 24

1 year

Question 25

A top is spinning on a table. What is the period of the spinning top? A. 4 pounds B. 8 dollars C. 0.05 seconds D. 3 cm

Answer 25

C. 0.05 seconds

Question 26

Which of the following waves is infrasonic? A. 4 MHz B. 400 kHz C. 28 Hz D. 2 Hz

Answer 26

D. 2 Hz

Question 27

Indentify the wave that is ultrasonic. A. 400 mHz B. 4 MHz C. 28 Hz D. 2 Hz

Answer 27

B. 4 MHz

Question 28

Which of these waves is ultrasonic and most useful in diagnostic sonography? A. 400 MHz B. 4 MHz C. 2 kHz D. 200,000 Hz

Answer 28

B. 4 MHz

Question 29

Identify all the waves that are inaudible. A. 4 MHz B. 400 kHz C. 28 Hz D. 2 Hz

Answer 29

A. 4 MHz B. 400 kHz D. 2 Hz

Question 30

Which of the following waves has the longest period? A. 2 MHz B. 4,000 Hz C. 6 Hz D. 1 kHz

Answer 30

C. 6 Hz

Question 31

Of the four waves whose periods are listed below, which has the highest frequency? A. 8 s B. 80 μs C. 8 Ms D. 800 ks

Answer 31

B. 80 μs

Question 32

Of the four waves whose frequencies are listed below, which has the shortest period? A. 12 kHz B. 6,000 Hz C. 205 Hz D. 1 kHz

Answer 32

A. 12 kHz

Question 33

Of the four waves whose periods are listed below, which had the lowest frequency? A. 8 s B. 80 μs C. 8 Ms D. 800 ks

Answer 33

C. 8 Ms

Question 34

The three “bigness” parameters…

Answer 34

Amplitude, power, intensity

Question 35

The bigness of the wave, or difference between the maximum value and the average or undisturbed value of an acoustic variable.

Answer 35

Amplitude

Question 36

Amplitude can have units of any of the acoustic variables, which are…

Answer 36

Pressure (pascals), density (g/cm^3), distance (particle motion)(cm/inches). Can also be expressed in decibels (dB)

Question 37

In clinical imaging, pressure amplitude ranges from…

Answer 37

1 million pascals (1 MPa) to 3 million pascals (3 MPa)

Question 38

Initially, amplitude is determined only by the ______. However, amplitude ______ as sound propagates through the body.

Answer 38

sound source, decreases

Question 39

The rate at which amplitude decreases as sound propagates depends on the characteristics of both the ______ and the ______.

Answer 39

Sound wave, medium

Question 40

True or false? A control on a basic ultrasound system allows the sonographer to alter initial amplitude of a wave.

Answer 40

True

Question 41

Measured from the middle, or undisturbed, value to the maximum value.

Answer 41

Amplitude

Question 42

Difference between maximum and minimum values of an acoustic variable. Twice the value of amplitude.

Answer 42

Peak-to-peak amplitude

Question 43

The rate of energy transfer or the rate at which work is performed.

Answer 43

Power

Question 44

Power has units of…

Answer 44

Watts

Question 45

In clinical imaging, typical powers range from…

Answer 45

0.004 to 0.90 watts (4 to 90 milliwatts).

Question 46

When power increases, amplitude…

Answer 46

Increases

Question 47

Mathematically, power is proportional to the wave’s amplitude _______.

Answer 47

Squared, a number multiplied by itself

Question 48

Just like amplitude, initial power is determined only by the _________, the ultrasound system.

Answer 48

Sound source

Question 49

True or False? There is no control on ultrasound systems that allows the sonographer to alter the initial power of the wave.

Answer 49

False

Question 50

When you think of power, think of a…

Answer 50

Light bulb

Question 51

Concentration of energy in a sound beam.

Answer 51

Intensity

Question 52

To calculate intensity, divide the beam’s _________ by the beam’s __________ area.

Answer 52

Power, cross-sectional

Question 53

Intensity relates to how the power in a wave _______ or is ________ in the space.

Answer 53

Spreads, distributed

Question 54

Intensity depends on both the power in the _____ and the _____ over which the power is applied.

Answer 54

Beam, area