1.
When a sonographer changes the transducer, the system is now changed or altered.
Correct Answer
A. True
Explanation
When a sonographer changes the transducer, it means that they are swapping out the device that is used to transmit and receive ultrasound waves. This change in transducer can result in a different frequency or beam shape being used, which can affect the quality and accuracy of the ultrasound images produced. Therefore, it can be said that the system is indeed changed or altered when the transducer is changed.
2.
The X axis on a graph runs up and down or vertical.
Correct Answer
B. False
Explanation
The X axis on a graph runs horizontally, not vertically. The vertical axis on a graph is called the Y axis.
3.
How are your exam scores related to your study time?
Correct Answer
A. A. Directly related or proportional to
Explanation
The correct answer is A. Directly related or proportional to. This means that there is a positive correlation between exam scores and study time. The more time a person spends studying, the higher their exam scores are likely to be.
4.
Which of the following is a unit of volume?
Correct Answer
C. C. Cubic inches
Explanation
Cubic inches is a unit of volume because it measures the amount of space occupied by an object in three dimensions. It is commonly used in engineering and manufacturing industries to measure the volume of small objects or components. Cubic inches are calculated by multiplying the length, width, and height of an object in inches.
5.
Which of the following is a unit of area?
Correct Answer
C. C. Centimeters squared
Explanation
Centimeters squared is a unit of area because it represents the measurement of a two-dimensional space. It is obtained by multiplying the length of an object by its width, both measured in centimeters. This unit is commonly used to measure the area of small objects or surfaces. Miles, millimeters, and yards are units of length and do not represent area.
6.
Which one of the following statements is correct?
Correct Answer
C. C. there are 1000 milliliters in one liter
Explanation
The correct answer is C. There are 1000 milliliters in one liter. This is a conversion between units of volume, where 1 liter is equal to 1000 milliliters.
7.
In the metric system, which one of the following prefixes matches the correct symbol?
Correct Answer
D. D. centi = c
Explanation
The correct answer is D. centi = c. In the metric system, the prefix "centi" is used to represent one hundredth of a unit. The symbol for centi is "c". This is commonly used in measurements such as centimeters (cm) or centigrams (cg), where "centi" indicates a fraction of the base unit.
8.
Which of the following correctly represents distance and time?
Correct Answer
B. B. meters per second
Explanation
The correct answer is B. meters per second. This is because distance is typically measured in meters and time is typically measured in seconds. Therefore, representing distance and time as meters per second is the most appropriate and commonly used unit of measurement.
9.
Which of the following is correct?
Correct Answer
B. B. millionth = .000001
Explanation
The correct answer is B. millionth = .000001. This is because "millionth" is a unit of measurement that represents one part out of a million. Therefore, it is equivalent to dividing 1 by 1,000,000, which gives us the decimal value of .000001.
10.
You perform a Doppler study on a heart valve and find the velocity through the aortic valve is 4 m/sec. The physician requests the velocity measurements in cm/sec. What velocity measurement would you give to the physician? cm/sec
Correct Answer
A. A. 400
Explanation
The correct answer is A. 400. To convert the velocity from m/sec to cm/sec, you need to multiply it by 100. Therefore, 4 m/sec is equal to 400 cm/sec.
11.
Which of the following is the reciprocal of a billion?
Correct Answer
C. C. 0.000000001
Explanation
The reciprocal of a number is obtained by dividing 1 by that number. In this case, the reciprocal of a billion would be 1 divided by a billion, which is equal to 0.000000001.
12.
How many centimeters are there in 30 millimeters?
Correct Answer
B. B. 3
Explanation
There are 10 millimeters in 1 centimeter. Therefore, to convert millimeters to centimeters, we divide the number of millimeters by 10. In this case, 30 millimeters divided by 10 equals 3 centimeters. So the correct answer is B. 3.
13.
Which of the following is required for the answer to a numerical question to be comprehensive?
Correct Answer
B. B. units
Explanation
To make the answer to a numerical question comprehensive, units are required. Units provide context and clarity to the numerical value, allowing for a better understanding of the answer. Without units, the numerical value alone may not convey the full meaning or significance of the answer. Units help to establish the scale, measurement, or quantity being referred to, ensuring that the answer is complete and meaningful in the given context.
14.
Given that there are 2.54 cm in one inch. You measure the length of the right kidney and it measures 12.7 cm how lond is the right kidney in inches?
Correct Answer
D. D. 5 inches
Explanation
The conversion factor given is that there are 2.54 cm in one inch. To convert from centimeters to inches, we divide the length in centimeters by the conversion factor. In this case, the length of the right kidney is 12.7 cm. Dividing 12.7 cm by 2.54 cm/inch gives us 5 inches. Therefore, the length of the right kidney is 5 inches.
15.
If two waves exist at the same location with the peaks and troughs in sync. and combine, this is known as?
Correct Answer
D. D. Constructive interference
Explanation
When two waves exist at the same location with their peaks and troughs in sync, they combine to create a new wave with a larger amplitude. This phenomenon is known as constructive interference. In constructive interference, the waves reinforce each other, resulting in a wave that has a higher intensity or energy than the individual waves. This can be observed in various situations, such as when two sound waves combine to create a louder sound or when two water waves combine to create a higher wave.
16.
The speed of sound in soft tissue is all of the following EXCEPT:
Correct Answer
B. B. 1.54 m/sec
Explanation
The speed of sound in soft tissue is commonly measured in meters per second (m/sec), centimeters per second (cm/s), or millimeters per microsecond (mm/usec). However, it is not typically measured in meters per second (m/sec), so option B, 1.54 m/sec, is the exception.
17.
Two waves arrive at the same location and interfere with each other. Then resultant wave is larger than the original wave. What has occurred?
Correct Answer
D. D. Constructive interferance
Explanation
When two waves interfere constructively, it means that the peaks of one wave align with the peaks of the other wave, resulting in an amplified wave. This occurs when the two waves are in phase and their amplitudes add up. As a result, the resultant wave is larger than the original waves.
18.
Two waves arrive at the same location and interfere with each other. Then resultant wave is smaller than the original wave. What has occurred?
Correct Answer
B. B. destructive interference
Explanation
Destructive interference occurs when two waves combine in such a way that they cancel each other out, resulting in a smaller amplitude or intensity compared to the original wave. This happens when the peaks of one wave align with the troughs of the other wave, causing them to interfere destructively.
19.
Which of the following transducers would have the greatest depth of penetration?
Correct Answer
A. 2.5 mHz
Explanation
The transducer with the greatest depth of penetration is the one with the lowest frequency because lower-frequency ultrasound waves can penetrate deeper into tissues. In this case, the transducer with 2.5 MHz (megahertz) would have the greatest depth of penetration.
20.
If the frequency of a continuous wave transducer is 5 MHz, which of the following is the correct answer for period?
Correct Answer
D. D. 0.0000002
Explanation
The period of a wave is the time it takes for one complete cycle to occur. It is the reciprocal of the frequency, meaning that the period is equal to 1 divided by the frequency. In this case, the frequency is 5 MHz, which means it has a frequency of 5 million cycles per second. Therefore, the period would be 1 divided by 5 million, which is equal to 0.0000002 seconds.
21.
What determines the period of an ultrasound wave?
Correct Answer
A. A. the transducer
Explanation
The source determines the period. The waves period is unrelated to the medium through which it travels.
22.
Which of the following cannot be considered a unit of frequency?
Correct Answer
A. A. cycles
Explanation
The term "cycles" is not a standard unit of frequency. Frequency is typically measured in hertz (Hz) or cycles per second. While "cycles" is often used informally to describe the number of repetitions or oscillations in a periodic waveform, it is not a recognized unit of frequency in scientific or technical contexts. Therefore, option A cannot be considered a unit of frequency.
23.
How are period and frequency related?
Correct Answer
C. C. inversely
Explanation
Period and frequency are inversely related. This means that as the period increases, the frequency decreases, and vice versa. The period refers to the time it takes for one complete cycle of a wave or oscillation to occur, while the frequency represents the number of cycles or oscillations that occur in a given time period. Since the period and frequency are reciprocals of each other, they have an inverse relationship.
24.
What is the range of frequencies emitted by transducers used in diagnostic ultrasound?
Correct Answer
D. D. 2 MHz to 10 MHz
Explanation
Transducers used in diagnostic ultrasound emit frequencies within the range of 2 MHz to 10 MHz. This range is commonly used in medical imaging as it provides a good balance between image resolution and tissue penetration. Frequencies below 2 MHz may provide better tissue penetration but lower resolution, while frequencies above 10 MHz may offer higher resolution but limited tissue penetration. Therefore, the range of 2 MHz to 10 MHz is considered optimal for most diagnostic ultrasound applications.
25.
What is the characteristic of acoustic waves with frequencies less than 20Hz?
Correct Answer
A. A. Humans chn't hear them
Explanation
Acoustic waves with frequencies less than 20Hz are considered infrasound. These low-frequency waves are below the range of human hearing, which typically ranges from 20Hz to 20,000Hz. Therefore, humans cannot perceive or hear these acoustic waves.
26.
What determines the initial amplitude of a sound wave?
Correct Answer
A. A. transducer
Explanation
The initial amplitude of a sound wave is determined by the transducer. A transducer is a device that converts one form of energy into another, such as converting sound waves into electrical signals. In the context of sound waves, the transducer is responsible for converting the physical vibrations of the medium into an electrical signal, which can then be amplified and heard as sound. Therefore, the transducer plays a crucial role in determining the initial amplitude of a sound wave.
27.
Mathematically, when a number is squared, the number is multiplied by?
Correct Answer
D. D. itself
Explanation
When a number is squared, it is multiplied by itself. This means that the number is multiplied by the number itself to give the squared value. For example, if we square the number 3, we multiply 3 by itself, resulting in 9. Therefore, the correct answer is D. itself.
28.
As sound travels through the body, what happens to the intensity of the wave?
Correct Answer
B. B. decreases
Explanation
As sound travels through the body, the intensity of the wave decreases. This is because sound waves encounter resistance and are absorbed or reflected by the various tissues and organs in the body. As the wave travels further, it loses energy and therefore its intensity decreases. Additionally, some of the sound energy is converted into other forms of energy, such as heat, further contributing to the decrease in intensity.
29.
The intensity of an ultrasound beam is defined as the ___________ in the beam ________ by the _______ of the beam?
Correct Answer
D. D. power, divided area
Explanation
The intensity of an ultrasound beam is defined as the power divided by the area of the beam. This means that the intensity is a measure of how much power is being transmitted through a given area. Therefore, the correct answer is D. power, divided area.
30.
What is the wavelength of 2 MHz sound in soft tissue?
Correct Answer
A. A. 0.77 mm
Explanation
The wavelength of a sound wave in a medium is given by the formula Î» = v/f, where Î» is the wavelength, v is the velocity of sound in the medium, and f is the frequency of the sound wave. In soft tissue, the velocity of sound is approximately 1540 m/s. Therefore, for a 2 MHz sound wave, the wavelength can be calculated as Î» = 1540 m/s / 2 Ã— 10^6 Hz = 0.77 mm.
31.
If the area of the beam increases, what happens to the intensity?
Correct Answer
B. B. It decreases
Explanation
When the area of the beam increases, the intensity decreases. This is because intensity is defined as the amount of power per unit area. So, if the area increases while the power remains constant, the power is spread out over a larger area, resulting in a decrease in intensity.
32.
What are the units for intensity?
Correct Answer
C. C. watts per cm squared
Explanation
The correct answer is C. watts per cm squared. Intensity is defined as power per unit area. Therefore, the units for intensity are watts per cm squared, as it represents the amount of power (watts) per unit area (cm squared).
33.
Which of the following can the sonographer change? More than one may apply.
Correct Answer
A. A. power
Explanation
A,B,C is the answer
34.
If power is doubled, what happens to intensity?
Correct Answer
A. A. it doubles
Explanation
When power is doubled, the intensity also doubles. This is because intensity is directly proportional to power. As power increases, more energy is being transferred per unit time, resulting in a higher intensity. Therefore, when power is doubled, the intensity also doubles.
35.
If amplitude is doubled, what happens to intensity?
Correct Answer
B. B. it quadruples
Explanation
When the amplitude of a wave is doubled, the intensity of the wave increases by a factor of four. This is because intensity is directly proportional to the square of the amplitude. So, if the amplitude is doubled, the intensity will be quadrupled.
36.
Wavelength is determined by:
Correct Answer
C. C. the source and the medium
Explanation
The wavelength of a wave is determined by both the source and the medium through which it travels. The source of the wave determines the frequency of the wave, which is the number of complete cycles of the wave that occur in a given time. The medium through which the wave travels affects the speed of the wave, which in turn affects the wavelength. Therefore, both the source and the medium play a role in determining the wavelength of a wave.
37.
What unit of measure is used for wavelength?
Correct Answer
A. A. mm
Explanation
The unit of measure used for wavelength is millimeters (mm). Wavelength is a measurement of the distance between two corresponding points on a wave, such as the distance between two peaks or two troughs. It is commonly used in the fields of physics and optics to describe the length of electromagnetic waves, sound waves, and other types of waves. The millimeter is a metric unit of length equal to one thousandth of a meter, making it a suitable unit for measuring the relatively small distances associated with wavelengths.
38.
If the tissue does not change but the frequency of the transducer increases, what happens to the wavelength?
Correct Answer
B. B. it decreases
Explanation
When the frequency of the transducer increases and the tissue does not change, the wavelength decreases. This is because wavelength and frequency are inversely proportional to each other. As the frequency increases, the distance between each wave decreases, resulting in a shorter wavelength.
39.
Whnat factors determine the propagation speed of sound? More than one answer.
Correct Answer
A. A. density
Explanation
Answer: A, D
40.
Sound travels fastest through tissue that is:
Correct Answer
A. A. less dense but more stiff
Explanation
Sound travels fastest through tissue that is less dense but more stiff because the speed of sound is inversely proportional to the density of the medium and directly proportional to the stiffness. In other words, when the tissue is less dense, the sound waves encounter fewer particles to interact with, allowing them to travel faster. Additionally, when the tissue is more stiff, the particles are held tightly together, allowing the sound waves to propagate more quickly. Therefore, a combination of less density and more stiffness allows sound to travel fastest through tissue.
41.
The amplitude is measured from: More than one answer.
Correct Answer
B. B. The middle value to the minimum value
Explanation
Answer B,C
42.
Which of the following represents the distance a pulse occupies in space from the start of the pulse to the end of the pulse?
Correct Answer
D. D. Spatial pulse length
Explanation
Spatial pulse length represents the distance a pulse occupies in space from the start of the pulse to the end of the pulse. It is a measure of the length of the pulse in the direction of propagation. The other options, such as pulse duration, pulse repetition period, pulse repetition frequency, and duty factor, are not related to the distance a pulse occupies in space.
43.
Which of the following represents the time form the start of one pulse to the start of the next pulse?
Correct Answer
B. B. Pulse repetition period
Explanation
The pulse repetition period represents the time from the start of one pulse to the start of the next pulse. It is the inverse of the pulse repetition frequency, which represents the number of pulses per second. The pulse duration refers to the time it takes for a single pulse to occur. Spatial pulse length refers to the length of the pulse in space. Duty factor represents the ratio of the pulse duration to the pulse repetition period.
44.
Which of the following units is associated with Pulse Repitition Period?
Correct Answer
A. A. microseconds
Explanation
The correct answer is A. microseconds. Pulse repetition period refers to the time interval between the start of one pulse and the start of the next pulse in a pulse train. It is typically measured in units of time, such as microseconds. The other options, Hz, millimeters, and %, are not directly related to the measurement of pulse repetition period.
45.
Which of the following units is associated with Spatial Pulse Length ?
Correct Answer
C. C. millimeters
Explanation
Spatial pulse length is a measure of the length of an ultrasound pulse in the direction of propagation. It is typically measured in millimeters. This parameter is important in ultrasound imaging as it affects the resolution of the image. A shorter spatial pulse length results in better resolution, allowing for clearer and more detailed images to be obtained. Therefore, the correct answer is C. millimeters.
46.
Which of the following units is associated with Duty Factor?
Correct Answer
D. D. %
Explanation
Duty Factor is a dimensionless quantity that represents the ratio of the pulse duration to the total period of a pulse waveform. It is commonly expressed as a percentage. A higher duty factor indicates that the pulse is on for a greater proportion of the total period, while a lower duty factor indicates that the pulse is on for a smaller proportion of the total period. Therefore, the correct unit associated with Duty Factor is % (percentage).
47.
Which of the following units is associated with Pulse Repetition Frequency?
Correct Answer
B. B. Hz
Explanation
Pulse Repetition Frequency (PRF) is a measurement used in radar and sonar systems to determine the number of pulses emitted per second. It is measured in Hertz (Hz), which is the unit for frequency. The higher the PRF, the more pulses are transmitted in a given time period, resulting in increased data collection and improved accuracy. Therefore, the correct unit associated with PRF is Hz.
48.
Which of the following units is associated with Pulse Duration?
Correct Answer
A. A. microseconds
Explanation
Pulse duration is a measure of the time duration of a single pulse. It is typically measured in units of time, such as microseconds. A pulse duration of 1 microsecond means that the pulse lasts for 1 millionth of a second. Therefore, option A, microseconds, is the correct unit associated with pulse duration.
49.
Which of the following pulsed wave parameters can the sonographer adjust?
Correct Answer
C. C. Pulse Repetition Period
Explanation
Answer C, D, E
50.
Which of the following pulsed wave parameters can the sonographer adjust?
Correct Answer
C. C. Pulse repetition period
Explanation
Answer C, D, E