Week 1 exam

Question 1

Sound can travel through all of the following except:

Answer 1

A vacuum

Question 2

An interaction of echoes that leads to reinforcement rather that to partial or total cancellation is known as:

Answer 2

Constructive interference

Question 3

On a diagram of a waveform, the peak above the baseline represents

Answer 3

Compression

Question 4

When you switch from a 2.5 MHz to a 5 MHz transducer, the sound wavelength:

Answer 4

halves

Question 5

The amount of a space within a specific boundary defines:

Answer 5

area

Question 6

What sound parameter is determined only by the medium?

Answer 6

Propagation speed

Question 7

If the frequency is increased, the __ will be __

Answer 7

velocity; unchanged

Question 8

A wave vibration at 20 cycles per second has a frequency of:

Answer 8

20 Hz

Question 9

For every increase of one in the powers of ten, the decimal point:

Answer 9

shifts one space to the right

Question 10

Which of the following is required for the answer to a numerical question to be comprehensive?

Answer 10

Units

Question 11

Proportionally related means:

Answer 11

two items are related, but the relationship is not specific

Question 12

Density is defined as:

Answer 12

mass per unit of volume

Question 13

How would the number 0.000001 be represented using scientific notation?

Answer 13

1.0x10^-6

Question 14

Which prefix equals 10^-3

Answer 14

milli

Question 15

Which of the following represents the number 1234 in scientific notation?

Answer 15

1.234x10^3

Question 16

Sound waves can go through a vacuum if the amplification is high enough

Answer 16

false

Question 17

The term compression zone describes a region of ___ in the medium, which is subjected to an ultrasound field

Answer 17

increased molecular density

Question 18

The definition of period of a wave cycle is

Answer 18

time for one complete cycle to occur

Question 19

Which of the following tissues are in order of propagation speed from fastest to slowest?

Answer 19

bone, blood, lung

Question 20

Ultrasound waves are best described as:

Answer 20

high-frequency longitudinal mechanical waves

Question 21

In scientific notation, a number with positive exponent has a value:

Answer 21

greater than one

Question 22

When waves combine to form a single wave of less amplitude, it is called:

Answer 22

destructive interference

Question 23

If the period decreases, the wavelength

Answer 23

decreases

Question 24

The sound wave from which frequency transducer travel faster in soft tissue?

Answer 24

they all travel the same speed

Question 25

As frequency increases,

Answer 25

propagation speed does not change

Question 26

Directly related means:

Answer 26

when one item increases or decreases, the second item responds the same direction

Question 27

The formula for intensity is

Answer 27

1 = power/area

Question 28

10^-3 equals:

Answer 28

1/1000

Question 29

What would the following sequence be in scientific notation? Milli, Kilo, Mega, Centi?

Answer 29

10^-3, 10^3, 10^6, 10^-2

Question 30

Waves transfer ___ from one location to another

Answer 30

energy

Question 31

What term is the reciprocal of Mega?

Answer 31

micro

Question 32

Which are appropriate complementary units

Answer 32

mega and micro

Question 32

Which of the following acoustic variables will change due to sound travel through a medium?

Answer 32

pressure

Question 33

The positive half of a pressure wave corresponds to:

Answer 33

compression

Question 34

Which of the following best equates to the value 7,500,000 Hz?

Answer 34

7.5 MHz

Question 35

Two waves arrive at a location at the same time. What event takes place?

Answer 35

interference

Question 36

Which of the following is not an acoustic parameter?

Answer 36

pressure

Question 37

What does compression and rarefaction change in the medium?

Answer 37

density

Question 38

Which of the following is NOT the average value for propagation speed

Answer 38

1.54 mm/s

Question 38

If the power is doubled, and the area remains the same, intensity is ___

Answer 38

doubled

Question 39

Two quantities are proportional if an increase in one quality leads to a/an ___ in the other

Answer 39

increase

Question 40

Circumferences are usually measured in:

Answer 40

cm

Question 41

Which of the following is defined as force per unit area?

Answer 41

pressure

Question 42

Bulk modulus is closely related to which of the following qualities?

Answer 42

stiffness

Question 43

Which has the slowest propagation speed?

Answer 43

lung

Question 44

If the power of a wave is increased by a factor of 10, what happens to the intensity of the wave?

Answer 44

it increases by a factor of 10

Question 45

If the period of a wave is increased by a factor of 2, what happens to the propagation velocity?

Answer 45

propagation velocity remains unchanged

Question 46

Intensity can be adjusted by the sonographer

Answer 46

true

Question 47

Which of the following bests describes ultrasound?

Answer 47

A mechanical vibration transmitted through a medium as a longitudinal wave

Question 48

Characteristics & features describing an ultrasound wave include:

Answer 48

Compression/ rarefraction longitudinal mechanical

Question 49

The number 10^3 is the same as:

Answer 49

one thousand

Question 50

Which sound waves are audible?

Answer 50

10 kHz

Question 51

Which of these ranges of frequencies would be considered for diagnostic ultrasound?

Answer 51

4 to 10 MHz

Question 52

If the propagation speed increases, with ___ stiffness

Answer 52

increased

Question 53

The maximum cyclical variation or change in a quantity of an acoustic variable, such as pressure, is known as___

Answer 53

amplitude

Question 54

The highest level of concentration of molecules in a wave is called

Answer 54

compression

Question 55

If the frequency of a sound wave is 5 Hz, the period will be:

Answer 55

1/5 second

Question 56

As sound travels through a medium, what term describes the effects of the medium on the sound wave?

Answer 56

Acoustic propagation properties

Question 57

Which of the following is equivalent to the prefix giga?

Answer 57

109

Question 58

The speed of sound traveling through soft tissue is:

Answer 58

1540 m/s

Question 59

A sonographer measures the perimeter of an anatomical structure. Which of the following choices is a reasonable value for the measurement?

Answer 59

15 mm

Question 60

If the amplitude of a wave doubles, the intensity will:

Answer 60

quadruple

Question 61

If transducer frequency remains constant but wavelength was shown to increase, which of the following is correct?

Answer 61

propagation velocity increased

Question 62

The formula for wavelength is

Answer 62

propagation speed / frequency

Question 63

Which of the following correctly defines acoustic frequency?

Answer 63

number of cycles in a second

Question 64

If frequency increases, wavelength

Answer 64

decreases

Question 65

Which of the following terms does not belong with the others?

Answer 65

wider molecular spacing

Question 66

What happens to the frequency of a sound wave if the wavelength is increased by a factor of 5?

Answer 66

frequency decreases by a factor of 5

Question 67

If two variables are inversely proportional, if one decreased by a factor of 5, then the other

Answer 67

increased by a factor of 5

Question 68

Density and propagation speed are

Answer 68

inversely related

Question 69

Diagnostic frequencies range between:

Answer 69

2.0 and 15.0 MHz

Question 70

If the ares is doubled, and the power remains the same, intensity is ___

Answer 70

halved

Question 71

Volume has which of the following units

Answer 71

Cm^3

Question 72

Inversely related means:

Answer 72

items are related as that the change in one creates an opposite change in the other

Question 73

Which of the following best describes direction of motion of the particles in a sound wave?

Answer 73

particle motion is parallel to the direction in which the waves are traveling