1.
The speed and energy of the electron stream as it passes across an x-ray tube is primarily controlled by the:
Correct Answer
A. Applied kilovoltage
Explanation
The speed and energy of the electron stream as it passes across an x-ray tube is primarily controlled by the applied kilovoltage. Kilovoltage (kV) determines the potential difference between the cathode and anode in the x-ray tube. Higher kV results in a greater acceleration of the electrons, leading to increased speed and energy. This affects the penetration power and quality of the x-ray beam produced. Therefore, the applied kilovoltage is the main factor controlling the speed and energy of the electron stream in an x-ray tube.
2.
To determine how fast an x-ray tube will dissipate heat after several exposures, which of the following should be used?
Correct Answer
A. Anode cooling chart
Explanation
The anode cooling chart should be used to determine how fast an x-ray tube will dissipate heat after several exposures. This chart provides information on the cooling capacity of the anode, which is crucial in preventing overheating of the tube. By referring to the anode cooling chart, operators can ensure that the x-ray tube is given sufficient time to cool down between exposures, thereby preventing damage to the tube and ensuring its longevity. The other options, such as the housing cooling chart, operator's manual, and radiographic rating chart, may provide useful information but are not specifically designed to determine heat dissipation.
3.
Which of the following charts permit the calculation of the time necessary for the housing to cool enough for additional exposures to be made?
Correct Answer
B. Housing colling charts
Explanation
Housing cooling charts permit the calculation of the time necessary for the housing to cool enough for additional exposures to be made. These charts provide information on the cooling time required for the X-ray tube housing after a certain number of exposures or a specific exposure time. By referring to the housing cooling chart, technicians can determine when it is safe to make additional exposures without risking overheating of the X-ray tube.
4.
The energy lost as the X-ray tube electrons pass through and interact with the outer orbital shell electrons of the tungsten target is commonly associated with the production of:
Correct Answer
C. Infrared radiation
Explanation
As the X-ray tube electrons interact with the outer orbital shell electrons of the tungsten target, energy is lost. This energy loss is commonly associated with the production of infrared radiation.
5.
The energy of the photons produced during the bremsstrahlung process is dependent upon the:
1. The energy of the projectile electrons.
2. The atomic number of the target material.
3. The distance between the electron and the nucleus.
Correct Answer
D. 1,2, and 3
Explanation
The energy of the photons produced during the bremsstrahlung process is dependent upon multiple factors. Firstly, the energy of the projectile electrons plays a role in determining the energy of the photons. Higher energy electrons will produce higher energy photons. Secondly, the atomic number of the target material also affects the energy of the photons. Higher atomic number materials will produce higher energy photons. Lastly, the distance between the electron and the nucleus can also impact the energy of the photons. Closer distances can result in higher energy photons. Therefore, all three factors - the energy of the projectile electrons, the atomic number of the target material, and the distance between the electron and the nucleus - contribute to the energy of the photons produced during the bremsstrahlung process.
6.
The penetrability of an X-ray photon is affected by all of the following EXCEPT:
Correct Answer
B. Mass of the pHoton
Explanation
The penetrability of an X-ray photon is affected by the frequency, wavelength, and energy of the photon. However, the mass of the photon does not affect its penetrability. This is because the mass of a photon is always zero, according to the theory of relativity. Therefore, the mass of the photon is not a factor in determining its penetrability through different materials.
7.
Which of the following factors will have a significant effect on the energies produced during characteristics x-ray production process?
Correct Answer
A. The atomic number of the material in the target of the xray tube
Explanation
The atomic number of the material in the target of the x-ray tube will have a significant effect on the energies produced during characteristic x-ray production process. This is because the atomic number determines the number of protons in the nucleus, which in turn affects the binding energies of the electrons in the atom. When high-energy electrons from the filament collide with the target material, they can cause the ejection of inner shell electrons. As these vacancies are filled by outer shell electrons, characteristic x-rays are emitted with energies specific to the target material's atomic number. Therefore, a higher atomic number will result in higher energy characteristic x-rays.
8.
All of the following factors are required for the production of x0rays EXCEPT:
Correct Answer
D. A strong magnetic field
Explanation
A strong magnetic field is not required for the production of x-rays. X-rays are generated by high velocity projectile electrons colliding with loosely bound (ionized) electrons in a target material with a high atomic number. The collision causes the electrons to release energy in the form of x-rays. A strong magnetic field is not involved in this process.
9.
The majority of X-rays produced in an X-ray tube are the result of:
Correct Answer
A. A rapid deceleration of projectile electrons as they pass through the target material
Explanation
The majority of X-rays produced in an X-ray tube are the result of a rapid deceleration of projectile electrons as they pass through the target material. When high-energy electrons collide with the target material, they undergo a rapid deceleration, causing them to lose energy. This loss of energy is emitted in the form of X-rays. Therefore, the correct answer is a rapid deceleration of projectile electrons as they pass through the target material.
10.
In the diagnostic energy region, approximately what percentage of electron stream energy is converted into x-rays?
Correct Answer
A. .2% - 1%
Explanation
In the diagnostic energy region, only a small percentage of electron stream energy is converted into x-rays, ranging from .2% to 1%. This means that the majority of the electron stream energy is not converted into x-rays, but is instead used for other purposes or lost as heat. Therefore, the conversion efficiency of electron stream energy into x-rays in the diagnostic energy region is relatively low.
11.
When a stream of fast-moving electrons interacts with the target of the anode, X-rays are generated by two different processes called:
Correct Answer
A. Bremsstrahlung and characteristic radiation
Explanation
When a stream of fast-moving electrons interacts with the target of the anode, X-rays are generated by two different processes called Bremsstrahlung and characteristic radiation. Bremsstrahlung is produced when the electrons are decelerated by the electric field of the nucleus, resulting in the emission of X-rays. Characteristic radiation is generated when the fast-moving electrons knock inner shell electrons out of their orbit, causing outer shell electrons to fill the vacancy and emit X-rays in the process. These two processes are the main mechanisms for the production of X-rays in this scenario.
12.
The maximum heat capacity of the anode of a radiographic tube is related to the:
1. diameter of the anode disk
2. design of the thermal envelope
3. The rotational speed of the anode disk
Correct Answer
D. 1, 2, and 3
Explanation
The maximum heat capacity of the anode of a radiographic tube is related to the diameter of the anode disk, the design of the thermal envelope, and the rotational speed of the anode disk. The diameter of the anode disk affects the surface area available for heat dissipation, thus influencing the maximum heat capacity. The design of the thermal envelope determines how efficiently heat is transferred away from the anode, affecting its maximum heat capacity. The rotational speed of the anode disk affects the time available for heat dissipation between exposures, which can also impact the maximum heat capacity. Therefore, all three factors are related to the maximum heat capacity of the anode.
13.
Excessive heating of the tube may lead to vaporization of the filament or anode. Over a long period of time, this may result in any of the following EXCEPT:
Correct Answer
D. An increase in the beam intensity
Explanation
Excessive heating of the tube can cause vaporization of the filament or anode, leading to various consequences. Arcing within the tube can occur due to the high temperatures, potentially damaging the equipment. Filtration of the beam may be affected as the heating can disrupt the proper functioning of the filtration system. The deterioration of the vacuum can also occur as the excessive heat can degrade the vacuum seal, impacting the overall performance of the tube. However, an increase in the beam intensity is not a likely outcome of excessive heating, as it is more related to factors such as the power input or adjustments of the tube settings.
14.
Surface irregularities on the face of the anode(pitting) are most often associated with a(an):
Correct Answer
C. Increased output of radiation due to the blooming of the focal spot
Explanation
Surface irregularities on the face of the anode (pitting) are most often associated with an increased output of radiation due to the blooming of the focal spot. Blooming refers to the spreading of the electron beam on the anode surface, causing pitting and surface irregularities. This can result in a larger effective focal spot size, leading to a higher radiation output. Excessive filtering by the vacuum in the tube, reduction in radiation output, or reduction in potential difference would not directly cause surface irregularities on the anode.
15.
At a potential of 70 kVp the projectile electrons will reach a speed of approximately half the speed of light
Correct Answer
A. True
Explanation
At a potential of 70 kVp, the electrons will experience a high acceleration due to the high voltage. This acceleration will cause the electrons to gain a significant amount of kinetic energy, resulting in them reaching a speed that is close to half the speed of light. This is because as the voltage increases, the kinetic energy of the electrons also increases, leading to a higher speed. Therefore, the statement is true.
16.
The maximum anode heat storage capacity of a radiographic tube is related to the type and size of the:
1. anode disk
2. thermal cushion
3. anode materials
Correct Answer
D. 1, 2, and 3
Explanation
The maximum anode heat storage capacity of a radiographic tube is related to the type and size of the anode disk, the thermal cushion, and the anode materials. The anode disk determines the surface area available for heat dissipation, while the thermal cushion helps to absorb and distribute the heat generated during operation. Additionally, the type and composition of the anode materials play a role in determining their ability to withstand and dissipate heat. Therefore, all three factors contribute to the maximum anode heat storage capacity.
17.
Which of the following portion of the induction motor of a rotating anode normally operates within the vacuum of the tube?
1. ball bearings
2. anode stem
3. rotor
Correct Answer
D. 1, 2, and 3
Explanation
The ball bearings, anode stem, and rotor of a rotating anode induction motor all operate within the vacuum of the tube. The ball bearings are responsible for supporting the rotor and allowing it to rotate smoothly within the vacuum. The anode stem connects the rotor to the anode, which is the target for the electron beam. The rotor itself is an essential component of the motor and also operates within the vacuum. Therefore, all three options (1, 2, and 3) are correct.
18.
The main function of the pyrex glass that forms the protective envelope of the x-ray tube is:
1. containment of the electron stream near the filament
2. containment of the vacuum within the X-ray tube
3. production of the static electrical field around the filament
Correct Answer
B. 2 only
Explanation
The correct answer is 2 only. The main function of the pyrex glass that forms the protective envelope of the x-ray tube is to contain the vacuum within the X-ray tube. The pyrex glass acts as a barrier to prevent air or any other gas from entering the tube, thus maintaining the necessary vacuum for the x-ray production. It also provides insulation and protection to the internal components of the tube from external influences. The containment of the electron stream near the filament (option 1) and the production of the static electrical field around the filament (option 3) are not the main functions of the pyrex glass envelope.
19.
The penetrability of an xray photon is effected by all of the following EXCEPT:
Correct Answer
B. Mass of the pHoton
Explanation
The penetrability of an x-ray photon is determined by its energy, wavelength, and frequency. The higher the energy, the more penetrable the photon is. Similarly, shorter wavelengths and higher frequencies also result in greater penetrability. However, the mass of the photon does not affect its penetrability. X-ray photons are massless particles, and their penetrability is solely determined by their energy, wavelength, and frequency.
20.
Which of the following is likely to result in the appearance of an overload light?
1. the use of an excessive source-to0mage receptor distance
2. the use of a technique that exceeds the thermal capacity of the anode
3. the failure of the radiographer to push in the Bucky tray
Correct Answer
B. 2 only
21.
Which of the following is a byproduct of the photoelectric effect interaction
1. bremsstrahlung radiation
2. photoelectron
3. characteristic radiation
Correct Answer
C. 2 and 3 only
Explanation
The photoelectric effect is the emission of electrons when light or other electromagnetic radiation is shone onto a material. The byproducts of this interaction can include photoelectrons, which are the emitted electrons, as well as characteristic radiation. Characteristic radiation refers to the emission of photons with specific energies that are characteristic of the material being irradiated. Therefore, the correct answer is 2 and 3 only.
22.
Which of the following describes the radiation that makes up the X-ray beam after it has traversed the patient?
Correct Answer
A. Exit or image formation (remnant) radiation
Explanation
After passing through the patient, the X-ray beam produces exit or image formation (remnant) radiation. This radiation is the result of the interaction between the X-ray beam and the patient's tissues. It contains information about the internal structures of the patient's body and is used to create the X-ray image. Primary radiation refers to the initial X-ray beam that is emitted from the X-ray tube. Secondary radiation refers to the radiation that is produced when the primary radiation interacts with the patient's tissues. Scatter radiation refers to the radiation that is deflected in different directions after interacting with the patient's tissues.
23.
The interaction between x-ray photons and tissue that is responsible for radiographic contrast, but that also contributes significantly to patient dose is:
Correct Answer
A. pHotoelectric effect
Explanation
The photoelectric effect is the interaction between x-ray photons and tissue that is responsible for radiographic contrast. It occurs when an x-ray photon interacts with an inner shell electron, causing it to be ejected from the atom. This interaction results in the absorption of the photon and the production of a characteristic x-ray photon or an Auger electron. The photoelectric effect contributes significantly to patient dose because it involves the complete absorption of the x-ray photon, increasing the amount of energy deposited in the patient's tissues.
24.
The photoelectric effect is more likely to occur with:
1. absorbers having a high Z number
2. absorbers having a high mass density
3. positive contrast media
Correct Answer
D. 1, 2, and 3
Explanation
The photoelectric effect is more likely to occur with absorbers that have a high Z number, high mass density, and positive contrast media. The high Z number indicates a higher atomic number, which means there are more electrons available for interaction with photons. The high mass density implies a higher concentration of atoms, increasing the likelihood of photon-electron interactions. Positive contrast media refers to substances that have a higher density than the surrounding tissue, making them more likely to absorb photons and cause the photoelectric effect. Therefore, all three factors contribute to the increased likelihood of the photoelectric effect.
25.
What is the term used to describe x-ray photon interaction with matter and the transference of a part of the photon's energy to matter?
Correct Answer
B. Scattering
Explanation
Scattering is the term used to describe x-ray photon interaction with matter and the transference of a part of the photon's energy to matter. Scattering occurs when the x-ray photon interacts with an atom or molecule in the material, causing it to change direction and lose some of its energy. This process is important in medical imaging and other applications as it helps to create contrast and capture information about the structure of the material being imaged.
26.
An incident X-ray photon of 37 keV strikes an electron with 40 keV binding energy. A scattered photon results with 37 keV energy. This describes:
Correct Answer
D. Coherent event
Explanation
This scenario describes a coherent event. In a coherent event, the incident photon interacts with an atom or molecule, causing the entire atom or molecule to vibrate and emit a scattered photon with the same energy as the incident photon. In this case, the incident photon with 37 keV energy strikes an electron with a binding energy of 40 keV, resulting in a scattered photon with 37 keV energy. This is consistent with a coherent event where the energy of the scattered photon remains unchanged.
27.
An incoming photon of 1 MeV interacts with an orbital electron causing ionization of the atom and a .9 MeV scattered photon. This describes an event called:
Correct Answer
C. Compoton scattering
Explanation
Compton scattering occurs when a photon interacts with an electron, causing the photon to lose energy and change direction. In this case, the incoming 1 MeV photon interacts with an orbital electron, resulting in ionization of the atom and a scattered photon with 0.9 MeV of energy. Therefore, the given scenario describes Compton scattering.
28.
The probability of occurrences of Compton interactions decreases as x-ray photon energy (kVp)
Correct Answer
B. Increases
Explanation
As the x-ray photon energy (kVp) increases, the probability of Compton interactions also increases. This is because Compton interactions occur when an x-ray photon interacts with an outer shell electron, causing the photon to scatter and lose some of its energy. Higher energy photons have a greater chance of interacting with electrons, leading to an increase in Compton interactions.
29.
The probability of occurance of the photoelectric absoprtion ______markedly as the atomic number of the irradiated material _____.
Correct Answer
C. Increases/increases
Explanation
The probability of occurrence of the photoelectric absorption increases as the atomic number of the irradiated material increases. This is because the photoelectric effect is more likely to occur in materials with higher atomic numbers due to the increased number of electrons available for interaction with the incident photons. Additionally, as the atomic number increases, the energy levels of the electrons become closer together, making it easier for the incident photons to eject electrons from the material.
30.
The type of interaction, in the diagnostic kV range, which is responsible for the radiographic contrast between bone and soft tissue is termed:
Correct Answer
D. pHotoelectric absorption
Explanation
In the diagnostic kV range, the interaction responsible for the radiographic contrast between bone and soft tissue is photoelectric absorption. Photoelectric absorption occurs when an incident x-ray photon interacts with an inner shell electron of an atom, causing the electron to be ejected and creating a characteristic x-ray photon. This interaction is more likely to occur in high atomic number materials like bone, resulting in higher absorption and therefore greater contrast between bone and soft tissue in radiographic images.
31.
Which of the following x-ray interactions with matter does NOT occur within the diagnostic x-ray range?
Correct Answer
C. Pair production
Explanation
Pair production is not an interaction that occurs within the diagnostic x-ray range. Pair production is a process in which a photon interacts with the electromagnetic field of a nucleus and creates an electron-positron pair. This process requires high-energy photons, typically above 1.02 MeV, which is outside the range of diagnostic x-rays. In the diagnostic x-ray range, the most common interactions are classical scattering, compton scattering, and photoelectric absorption.