1.
Who is given credit for the discovery of X-ray?
Correct Answer
B. Wilhelm Roentgen
Explanation
Wilhelm Roentgen is given credit for the discovery of X-ray. In 1895, Roentgen accidentally discovered X-rays while experimenting with cathode rays. He noticed that a fluorescent screen in his lab started to glow even though it was not directly exposed to the cathode rays. Roentgen conducted further experiments and found that these rays could pass through certain substances and create images of the internal structures of objects. This groundbreaking discovery revolutionized the field of medicine and led to the development of X-ray technology, which is widely used for diagnostic purposes today.
2.
There are four types of radiation-matter interactions that can contribute to the total attenuation. These are:
Correct Answer
A. Compton scattering, pair production, pHotoelectric absorption, rayleigh scattering
Explanation
The correct answer is Compton scattering, pair production, photoelectric absorption, rayleigh scattering. This answer correctly lists the four types of radiation-matter interactions that can contribute to the total attenuation. Compton scattering occurs when a photon interacts with an electron, causing it to scatter and lose energy. Pair production involves the creation of an electron-positron pair from a high-energy photon. Photoelectric absorption occurs when a photon is absorbed by an atom, causing an electron to be ejected. Rayleigh scattering is the scattering of photons by atoms or molecules, resulting in a change in direction without a change in energy.
3.
X-rays and Gamma rays are a form of:
Correct Answer
C. Electromagnetic Radiation
Explanation
X-rays and Gamma rays are a form of electromagnetic radiation. Electromagnetic radiation consists of waves of electric and magnetic fields that travel through space. X-rays and Gamma rays have high energy and short wavelengths, making them part of the high-energy end of the electromagnetic spectrum. They share similar properties with other forms of electromagnetic radiation, such as visible light and radio waves, but differ in terms of energy and wavelength.
4.
Who is given credit for the discovery of radioactive materials?
Correct Answer
A. Henri Becquerel
Explanation
Henri Becquerel is given credit for the discovery of radioactive materials. In 1896, while conducting experiments with uranium salts, Becquerel accidentally discovered that these salts emitted a form of radiation that could penetrate through opaque materials. This discovery laid the foundation for the field of nuclear physics and led to further research by scientists like Marie Curie, who later coined the term "radioactivity" and made significant contributions to the understanding of radioactive elements. Wilhelm Roentgen, on the other hand, is credited with the discovery of X-rays, which are a different form of radiation. Pierre Curie was Marie Curie's husband and collaborator in their research on radioactivity.
5.
A specific radioactive source will always produce gamma rays at the same:
Correct Answer
C. Energy Levels
Explanation
The correct answer is "Energy Levels". This means that a specific radioactive source will always produce gamma rays with the same energy levels. The energy levels of gamma rays are determined by the specific radioactive isotope undergoing decay. Regardless of the intensity or activity of the source, the energy levels of the gamma rays emitted will remain constant.
6.
Higher energy radiation will have more:
Correct Answer
C. Penetrating Power
Explanation
Higher energy radiation will have more penetrating power. This is because higher energy radiation consists of photons with greater energy levels, allowing them to penetrate through materials more effectively. The higher energy enables the radiation to interact with atoms and molecules in a more forceful manner, allowing it to pass through thicker or denser materials. Therefore, higher energy radiation is capable of penetrating deeper into objects compared to lower energy radiation.
7.
X-rays and Gamma rays present a health risk because they are a form of ionizing radiation, which means that the radiation has enough energy to:
Correct Answer
B. Break chemical bonds
Explanation
X-rays and Gamma rays have high energy levels, making them ionizing radiation. This means that they have enough energy to break chemical bonds. When they interact with molecules in the body, they can cause damage by breaking the bonds that hold molecules together. This can lead to various health risks and potential harm to living tissues.
8.
X-rays and Gamma rays have significant penetrating power due to their:
Correct Answer
A. Short Wavelength
Explanation
X-rays and Gamma rays have significant penetrating power due to their short wavelength. Shorter wavelengths have higher energy levels, allowing them to easily pass through materials that longer wavelengths cannot penetrate. This is why X-rays and Gamma rays are commonly used in medical imaging and radiation therapy, as they can pass through the body to create detailed images or target cancer cells.
9.
Ionizing radiation can be used in industrial radiography because the health hazards:
Correct Answer
B. Are minimized through controls and procedures
Explanation
Ionizing radiation can be used in industrial radiography because the health hazards are minimized through controls and procedures. This means that specific measures are put in place to reduce the risks associated with exposure to radiation. These controls and procedures ensure that workers are protected and that the potential harm to their health is minimized. By implementing these measures, the use of ionizing radiation in industrial radiography can be done safely and effectively.
10.
X-rays and Gamma rays:
Correct Answer
A. Always travel in a straight line
Explanation
X-rays and Gamma rays always travel in a straight line because they are forms of electromagnetic radiation. Electromagnetic radiation, including X-rays and Gamma rays, consists of waves that propagate in a straight line. This means that they do not deviate from their path unless they encounter an obstacle or are influenced by external factors such as scattering or absorption. Therefore, the correct answer is that X-rays and Gamma rays always travel in a straight line.
11.
X-rays and Gamma rays are often referred to as photons because:
Correct Answer
C. They occur as small packets of energy
Explanation
X-rays and Gamma rays are often referred to as photons because they occur as small packets of energy. Photons are the fundamental particles of electromagnetic radiation, including X-rays and Gamma rays. These particles do not possess a charge and do not have mass. Instead, they exist as discrete bundles or packets of energy, which is why they are referred to as photons.
12.
X-rays and Gamma rays:
Correct Answer
D. Differ only in their source
Explanation
X-rays and gamma rays differ only in their source. While both are forms of electromagnetic radiation, X-rays are produced when high-speed electrons collide with a metal target, while gamma rays are emitted from the nucleus of an atom during radioactive decay. This means that X-rays can be generated in a laboratory setting using X-ray machines, while gamma rays are typically emitted naturally from radioactive materials or nuclear reactions. Other than their source of production, X-rays and gamma rays have similar properties and can both be harmful to living organisms.
13.
Newtons Inverse Square Law is useful in radiography because it indicates how the radiation intensity is affected by:
Correct Answer
B. Distance from the source
Explanation
Newtons Inverse Square Law states that the intensity of radiation is inversely proportional to the square of the distance from the source. This means that as the distance from the source increases, the radiation intensity decreases. Therefore, the correct answer is "Distance from the source" because it accurately reflects how the radiation intensity is affected by the distance between the source and the object being radiographed.
14.
The rate at which a radioactive isotope changes to a more stable atom is know as the:
Correct Answer
A. Isotope decay rate
Explanation
The rate at which a radioactive isotope changes to a more stable atom is known as the isotope decay rate. This refers to the speed at which the atoms of a radioactive isotope undergo radioactive decay, transforming into a different element or isotope. It is a measure of the stability of the isotope and can vary depending on the specific isotope in question. The isotope decay rate is an important factor in understanding the behavior and characteristics of radioactive materials.
15.
Attenuation of radiation is due to:
Correct Answer
D. Both A and B
Explanation
Attenuation of radiation occurs due to both absorption and scattering. Absorption refers to the process in which the energy of radiation is absorbed by the material it passes through, resulting in a decrease in its intensity. Scattering, on the other hand, involves the redirection of radiation in different directions when it interacts with particles or objects in its path. Both absorption and scattering contribute to the reduction of radiation intensity, leading to attenuation. Radioactive decay, although relevant to the behavior of radioactive materials, does not directly contribute to the attenuation of radiation.
16.
The number of X-ray or Gamma photons that are transmitted through a material depends on the:
Correct Answer
D. All of the above
Explanation
The number of X-ray or Gamma photons that are transmitted through a material depends on multiple factors. Firstly, the energy of the photons plays a role in determining their ability to penetrate the material. Higher energy photons are more likely to pass through. Secondly, the thickness of the material also affects transmission. Thicker materials are more likely to block the photons. Lastly, the atomic number of the material is important as it determines the density and composition of the material, which in turn affects the interaction of photons with the material. Therefore, all of the above factors influence the transmission of X-ray or Gamma photons through a material.
17.
After traveling through two half-value layers, the incident radiation has been reduced to:
Correct Answer
D. None of the above
18.
The thickness of any given material where 50% of the incident energy has been attenuated is known as the:
Correct Answer
A. Half-value layer
Explanation
The half-value layer refers to the thickness of a material where 50% of the incident energy has been attenuated. It is a measure of the material's ability to absorb or attenuate radiation. The linear attenuation coefficient, decay rate, and mass attenuation coefficient are not specifically related to the thickness at which 50% of the energy is attenuated.
19.
Undercut is the loss of resolution at a sharp, thickness transition area due to:
Correct Answer
D. Scattering within the film
Explanation
Undercut refers to the loss of resolution at a sharp, thickness transition area. In this case, the correct answer is "Scattering within the film". This means that the loss of resolution occurs due to scattering of the film material itself. Scattering refers to the phenomenon where light or other electromagnetic radiation is deflected or scattered in different directions when it interacts with particles or irregularities within a medium. In the context of the given question, the film material scatters the radiation, leading to a loss of resolution at the sharp transition area.
20.
Unexposed X-ray film is comprised of a plastic, transparent base coated with an emulsion containing radiation-sensitive particle known as:
Correct Answer
B. Silver halide grains
Explanation
Unexposed X-ray film is comprised of a plastic, transparent base coated with an emulsion containing radiation-sensitive particles known as silver halide grains. These grains are responsible for capturing the radiation and forming an invisible latent image on the film. When the film is developed, the silver halide grains are reduced to metallic silver crystals, which form the visible image on the film. Therefore, the correct answer is silver halide grains.
21.
Collimators are used to:
Correct Answer
A. Reduce the radiation beam spread
Explanation
Collimators are used to reduce the radiation beam spread. They are devices that restrict the size of the radiation beam, allowing for a more focused and controlled delivery of radiation. By reducing the spread of the beam, collimators help to ensure that the radiation is delivered precisely to the intended target area, minimizing the exposure to surrounding healthy tissues. This is particularly important in medical imaging and radiation therapy, where accurate targeting is crucial for effective treatment and minimizing potential side effects.
22.
Bremsstrahlung production of X-rays produces radiation that is composed of:
Correct Answer
B. A continuous spectrum of energies over some range
Explanation
Bremsstrahlung production of X-rays occurs when a high-energy electron is decelerated or deflected by the electric field of a nucleus. This process results in the emission of X-rays with a continuous spectrum of energies over a range. Unlike other forms of X-ray production, such as characteristic X-rays, which have specific energies corresponding to electron transitions within atoms, bremsstrahlung X-rays have a range of energies because they are produced by the deceleration of electrons with varying initial energies. Therefore, the correct answer is "A continuous spectrum of energies over some range."
23.
Exposure to ionizing radiation can be limited:
Correct Answer
D. All of the above
Explanation
Exposure to ionizing radiation can be limited through various methods. Shielding refers to the use of barriers or materials that can block or absorb radiation, reducing the amount that reaches an individual. Increasing distance from the radiation source also helps in reducing exposure, as the intensity of radiation decreases with distance. Additionally, limiting the time spent in the presence of radiation reduces overall exposure. Therefore, all of the mentioned methods can effectively limit exposure to ionizing radiation.
24.
X-ray generators produce radiation through:
Correct Answer
D. Both A and B
Explanation
X-ray generators produce radiation through both Bremsstrahlung processes and K-shell emission processes. Bremsstrahlung processes occur when electrons are decelerated by the electric field of a target material, causing them to emit X-rays. K-shell emission processes involve the excitation of inner-shell electrons in the target material, followed by their release of energy in the form of X-rays. Therefore, the correct answer is "Both A and B."
25.
Manmade sources of radioactive sources are produced by:
Correct Answer
C. Introducing an extra neutron to the atoms of the source material
Explanation
Manmade sources of radioactive sources are produced by introducing an extra neutron to the atoms of the source material. This process is known as neutron activation and is commonly used to create radioactive isotopes for various purposes, such as medical imaging, industrial applications, and scientific research. By adding an extra neutron to the atoms, the stability of the nucleus is disrupted, leading to the emission of radiation.
26.
Two of the more common industrial Gamma-ray sources are:
Correct Answer
A. Cobalt-60 and iridium-192
Explanation
Cobalt-60 and iridium-192 are commonly used as industrial gamma-ray sources. Cobalt-60 is a radioactive isotope of cobalt that emits gamma rays, making it suitable for industrial applications such as sterilization and radiography. Iridium-192 is also a radioactive isotope that emits gamma rays and is used in industrial radiography for non-destructive testing of materials. These two isotopes are widely used due to their ability to produce high-energy gamma rays and their long half-lives, allowing for extended use in industrial settings.
27.
Stationary lab or shop X-ray systems usually rely on what to limit exposure to the radiation?
Correct Answer
C. Shielding
Explanation
Stationary lab or shop X-ray systems rely on shielding to limit exposure to radiation. Shielding is a protective barrier made of lead or other dense materials that absorb and block radiation. It is designed to prevent the radiation from escaping the X-ray system and reaching the surrounding area, thus reducing the risk of exposure to individuals nearby. By using shielding, the radiation is contained within the system, ensuring the safety of both operators and anyone in the vicinity.
28.
Radiographic contrast describe:
Correct Answer
B. The differences in pHotograpHic density in a radiograpH
Explanation
Radiographic contrast refers to the differences in photographic density in a radiograph. It is a measure of the variation in shades of gray on the image, which helps to distinguish different structures and tissues. Higher contrast means a greater difference in density between adjacent areas, resulting in a more distinct and clear image. Therefore, this answer accurately describes the concept of radiographic contrast.
29.
Which of the following does not affect radiographic contrast?
Correct Answer
D. The level of current used for the exposure
Explanation
The level of current used for the exposure does not affect radiographic contrast. Radiographic contrast is determined by the attenuation differences in the component being inspected, the wavelength of the radiation used, and the amount of scattered radiation. The level of current used for the exposure primarily affects the intensity or brightness of the image, but it does not directly impact the contrast between different areas in the image.
30.
Film contrast is determined by:
Correct Answer
D. Both A and B
Explanation
Film contrast is determined by both the type of film used and the process by which the film was developed. The type of film used can affect the contrast as different films have different sensitivities to light and can produce different levels of contrast. Additionally, the process of developing the film can also impact the contrast, as different development techniques can alter the appearance of the image and enhance or reduce contrast. Therefore, both factors play a role in determining the film contrast.
31.
When penetrating radiation is directed at a material, the radiation intensity decreases:
Correct Answer
A. Decreases exponentially with increasing material thickness
Explanation
When penetrating radiation is directed at a material, the radiation intensity decreases exponentially with increasing material thickness. This means that as the material gets thicker, the intensity of the radiation decreases at an increasing rate. This can be explained by the fact that as the radiation passes through the material, it interacts with the atoms and molecules in the material, causing it to lose energy. The more material there is for the radiation to interact with, the more energy it loses, resulting in a decrease in intensity.
32.
The factor that indicates how much attenuation will take place per centimeter is known as the:
Correct Answer
B. Linear attenuation coefficient
Explanation
The linear attenuation coefficient is a factor that indicates the amount of attenuation that will occur per centimeter. It is a measure of how much a material will reduce the intensity of a beam of radiation as it passes through. The higher the linear attenuation coefficient, the greater the attenuation will be. This coefficient is important in various fields such as medical imaging and radiation therapy, as it helps determine the amount of radiation that will be absorbed by different materials.
33.
The main advantage of real-time radiography over film is:
Correct Answer
B. Inspection can be performed more rapidly
Explanation
Real-time radiography allows for immediate imaging and visualization of the inspected object, eliminating the need for film processing and development. This significantly reduces the time required to perform inspections, making the process faster and more efficient. This advantage is particularly beneficial in industries where time is crucial, such as medical imaging or industrial quality control.
34.
Which two types of radiation-matter interactions account for the majority of attenuation in typical industrial radiography?
Correct Answer
A. Compton Scattering and pHotoelectric absorption
Explanation
Compton scattering and photoelectric absorption are the two types of radiation-matter interactions that account for the majority of attenuation in typical industrial radiography. Compton scattering occurs when a photon interacts with an outer-shell electron, causing the photon to lose energy and change direction. Photoelectric absorption occurs when a photon interacts with an inner-shell electron, causing the electron to be ejected and the photon to be absorbed. These two processes are the primary mechanisms by which radiation is attenuated in industrial radiography.
35.
In comparison with lower-voltage radiographs, high voltage radiographic images have:
Correct Answer
A. Less contrast sensitivity
Explanation
High voltage radiographic images have less contrast sensitivity compared to lower-voltage radiographs. This means that the differences in brightness between different areas of the image are less pronounced. Lower-voltage radiographs, on the other hand, would have greater contrast sensitivity, meaning that the differences in brightness between different areas of the image would be more noticeable.
36.
A radiograph made with an exposure of 8 mAm produces a density of 1.8. The sensitometric curve shows a difference in relative exposure between a density of 1.8 and the target density of 2.5 is 4. What must the new exposure time be to produce a radiograph with a density of 2.5?
Correct Answer
C. 32 mAminutes
Explanation
The sensitometric curve shows that there is a difference in relative exposure of 4 between a density of 1.8 and the target density of 2.5. Since the initial exposure of 8 mAm produced a density of 1.8, we need to increase the exposure by 4 times to reach a density of 2.5. Therefore, the new exposure time should be 8 mAm x 4 = 32 mAminutes.
37.
When using geometric magnefication to produce a radiograph, the penumbra will be reduced by:
Correct Answer
C. A smaller source spot size
Explanation
A smaller source spot size will reduce the penumbra when using geometric magnification to produce a radiograph. The penumbra refers to the blurring or fuzziness around the edges of an image. By reducing the source spot size, the X-ray beam becomes more focused and concentrated, resulting in sharper and more defined edges in the radiograph. This reduces the blurring effect and improves the overall image quality.
38.
When flaws are in unknown locations, radiography is best suited for the detection of:
Correct Answer
A. Volumetric defects such as porosity
Explanation
Radiography is a non-destructive testing method that uses X-rays or gamma rays to examine the internal structure of an object. It is most effective in detecting volumetric defects such as porosity, which refers to the presence of voids or air pockets within a material. This is because radiography can provide a 2D or 3D image of the object, allowing for the identification of irregularities in its internal structure. On the other hand, tight linear defects like cracks and material delaminations may not be as easily detectable using radiography, as they may require other testing methods such as ultrasonic testing or visual inspection.
39.
The amount of geometric unsharpness in a radiograph is affected by:
Correct Answer
D. All of the above
Explanation
The amount of geometric unsharpness in a radiograph is affected by the source to film distance, the source to object distance, and the size of the source. The source to film distance refers to the distance between the radiation source and the film, and a longer distance can result in increased unsharpness. Similarly, the source to object distance, which is the distance between the radiation source and the object being radiographed, can also impact unsharpness. Additionally, the size of the source plays a role in determining the level of unsharpness, as a larger source can lead to more blurring. Therefore, all of these factors affect the amount of geometric unsharpness in a radiograph.
40.
Lowering the energy of the radiation used to produce a radiograph will generally result in:
Correct Answer
D. All of the above
Explanation
Lowering the energy of the radiation used to produce a radiograph will generally result in all of the above. When the energy of the radiation is reduced, it leads to less latitude, meaning that there is a narrower range of exposures that can be captured. This results in higher contrast sensitivity, as there is a greater differentiation between the different shades of gray in the image. Additionally, a lower energy radiation requires a longer exposure time to compensate for the reduced energy, allowing enough radiation to reach the film or sensor to create a properly exposed image.
41.
Radiation beam filters are sometime used in X-ray radiography to:
Correct Answer
D. Both A and B
Explanation
The purpose of the filters (often made of materials like aluminum) is to filter out lower energy X-ray photons from the beam because these photons are less likely to penetrate the patient and reach the detector. They would only add to the dose without contributing to the image quality. By removing them, the overall contrast of the radiographic image is improved, making it easier to differentiate between different types of tissues.
42.
Which of the following is not a strength of radiographic inspection?
Correct Answer
D. Access to both side of the test sample is required
Explanation
Radiographic inspection is a non-destructive testing method that uses X-rays or gamma rays to examine the internal structure of an object. It is widely used in industries such as manufacturing, aerospace, and healthcare. One of the strengths of radiographic inspection is that it can detect both surface and subsurface features, providing a comprehensive analysis of the test sample. Additionally, it can be used to inspect assembled components, allowing for the examination of complex structures. Another strength is that radiographic inspection is not limited to a specific material type, making it versatile in various applications. However, a limitation of radiographic inspection is that it requires access to both sides of the test sample, which may be challenging in certain situations.
43.
Image quality indicators (IQIs) provide information about the level of:
Correct Answer
A. Resolution and contrast sensitivity
Explanation
Image quality indicators (IQIs) are used to assess the quality of an image. They provide information about two important aspects: resolution and contrast sensitivity. Resolution refers to the level of detail that can be seen in an image, while contrast sensitivity relates to the ability to distinguish between different shades of gray. By evaluating both resolution and contrast sensitivity, IQIs can help determine the overall quality and clarity of an image.
44.
On a film radiograph, an area of high density in the test component will appear:
Correct Answer
A. Lighter than the surrounding area
Explanation
On a film radiograph, an area of high density in the test component will appear lighter than the surrounding area. This is because the film radiograph captures the amount of radiation that passes through the test component. Areas of high density in the test component will absorb more radiation, resulting in less radiation reaching the film and causing it to appear lighter. Conversely, areas of low density will allow more radiation to pass through, causing them to appear darker on the film radiograph.
45.
The drive cable of a gamma ray exposure device (camera) allows the radiographer to:
Correct Answer
C. Move the source in and out of the camera while maintaining a safe distance
Explanation
The drive cable of a gamma ray exposure device (camera) allows the radiographer to move the source in and out of the camera while maintaining a safe distance. This means that the radiographer can control the exposure of gamma rays by adjusting the position of the source without having to physically handle the camera or be in close proximity to the radiation source. This ensures the safety of the radiographer by minimizing their exposure to gamma rays.
46.
Computed tomography X-ray techniques allow the test component to be:
Correct Answer
A. Viewed in various cross-sectional slices
Explanation
Computed tomography X-ray techniques use a series of X-ray images taken from different angles to create cross-sectional slices of the test component. This allows for a detailed view of the internal structure and provides valuable information about any abnormalities or defects. By analyzing these cross-sectional slices, technicians can identify the location, size, and shape of any abnormalities, making it an effective tool for diagnosing and monitoring various medical conditions. Therefore, the correct answer is that the test component can be viewed in various cross-sectional slices.
47.
Thin sheets of lead foil in contact with the film during exposure increase the film density because:
Correct Answer
C. Incident radiation liberates electrons which help to expose the film
Explanation
Thin sheets of lead foil in contact with the film during exposure increase the film density because incident radiation liberates electrons which help to expose the film. When radiation passes through the lead foil, it interacts with the atoms in the foil and transfers energy to them. This energy then liberates electrons from the atoms in the foil. These liberated electrons then travel towards the film and contribute to the exposure of the film, resulting in an increase in film density.
48.
Image quality indicators are usually placed:
Correct Answer
C. On the front side of the test component in an area of similar thickness to the primary area of interest
Explanation
Image quality indicators are usually placed on the front side of the test component in an area of similar thickness to the primary area of interest. This placement ensures that the indicator will accurately represent the image quality in the area of interest. Placing the indicator on the front side also allows for easy visibility and evaluation of the image quality. Additionally, placing it in an area of similar thickness helps to ensure that the indicator will be exposed to the same conditions as the primary area of interest, providing a more accurate assessment of the image quality.
49.
Radiographic inspection should be used for crack detection only when:
Correct Answer
D. The orientation of the crack is known
Explanation
Radiographic inspection should be used for crack detection only when the orientation of the crack is known. This is because radiographic inspection involves the use of X-rays or gamma rays to create an image of the internal structure of a component. By knowing the orientation of the crack, the inspector can position the X-ray or gamma ray source and detector in such a way that the crack can be clearly detected in the resulting image. If the orientation of the crack is not known, it may be difficult to position the equipment properly and accurately detect the crack.
50.
The target of an X-ray tube is often made out of tungsten because:
Correct Answer
A. It has a high atomic mass which will result in more X-rays being generated due to atomic particle interactions
Explanation
Tungsten is often used as the target material in X-ray tubes because it has a high atomic mass. This high atomic mass allows for more interactions between the atomic particles, resulting in the generation of more X-rays. The other options, such as being an inexpensive material and having high thermal conductivity, are not the main reasons for choosing tungsten as the target material.