Moa Chapters 1, 2, 4, 5 Practice Test

According to the laws of physics, electromagnetic energy, which includes light, travels at a constant speed in a vacuum, known as the speed of light. This speed is approximately 299,792,458 meters per second. Therefore, it is correct to say that all electromagnetic energy travels at the speed of light.

The production of x-rays requires three essential components: a source of electrons, a target, and high voltage. The source of electrons provides the necessary particles for the x-ray production process. The target is the material that the electrons collide with, resulting in the generation of x-rays. Lastly, high voltage is required to accelerate the electrons towards the target with sufficient energy. Therefore, all three components are essential for x-ray production to occur.

The statement "X-rays were discovered in 1895 by Thomas Edison" is false. X-rays were actually discovered by Wilhelm Conrad Roentgen in 1895, not Thomas Edison. Roentgen was a German physicist who accidentally discovered X-rays while experimenting with cathode rays. Edison, on the other hand, was an American inventor and businessman known for his contributions to the development of various devices such as the phonograph and the electric light bulb.

Wavelength is the correct answer because it refers to the distance between the crests of two adjacent waves. It is a measure of the length of one complete wave cycle and is usually represented by the Greek letter lambda (λ). Wavelength is an important concept in understanding wave phenomena and is commonly used in various fields such as physics, optics, and telecommunications.

Scatter radiation refers to the secondary radiation that is produced when the primary beam interacts with the patient's body. This secondary radiation has less energy than the primary beam because it undergoes multiple interactions and loses some of its energy in the process. Therefore, the statement that scatter radiation has less energy than the primary beam is true.

Mass is the correct answer because it refers to the quantity of matter that occupies physical space. It is a fundamental property of matter and is measured in units like kilograms or pounds. Inertia, on the other hand, is the resistance of an object to changes in its motion, velocity is the rate of change of an object's position, and atomic number is a property specific to atoms indicating the number of protons in its nucleus.

X-rays are a form of electromagnetic radiation that can travel in straight lines, which is why they can be used to create clear images of internal structures. They also have enough energy to cause biological effects in tissues, which is why protective measures are necessary when working with them. Additionally, x-rays travel at the speed of light, allowing for rapid imaging and diagnosis. Therefore, all three characteristics listed (1, 2, and 3) are true for x-rays.

The positively charged portion of the x-ray tube is the anode/target. In an x-ray tube, the anode is the positively charged electrode where the x-rays are produced. When high-speed electrons from the cathode strike the anode, they generate x-rays through the process of bremsstrahlung radiation. The anode is typically made of a tungsten alloy, which has a high melting point and can withstand the high temperatures generated during x-ray production. The target refers to the specific area on the anode where the electrons strike to produce x-rays.

The correct answer is 80,000 volts because kilovolts is a unit of electrical potential difference, and 1 kilovolt is equal to 1,000 volts. Therefore, 80 kilovolts would be equal to 80,000 volts.

Wilhem's first X-ray exposure lasted for 15 minutes. This duration is significant as it indicates the amount of time he was exposed to X-ray radiation. The length of exposure is an important factor to consider in terms of potential health risks and the effectiveness of the X-ray procedure. It is crucial to limit exposure to X-rays to ensure the safety and well-being of the patient.

The image receptor/IR is responsible for receiving and recording the radiation that exits from the patient. It acts as a sensor that captures the image created by the radiation, allowing healthcare professionals to visualize and analyze it. This is an essential function in medical imaging as it enables the diagnosis and treatment of various conditions.

Radiographs are the proper term for "pictures" produced with x-rays. X-rays are used in medical imaging to create images of the internal structures of the body. These images, known as radiographs, allow healthcare professionals to diagnose and monitor various medical conditions. The term "radiographs" specifically refers to images produced using x-rays, distinguishing them from other types of pictures such as lithographs, prints, or photographs.

An atom that has lost or gained an electron is referred to as an ion. When an atom loses an electron, it becomes positively charged and is called a cation. On the other hand, when an atom gains an electron, it becomes negatively charged and is called an anion. Ions play a crucial role in chemical reactions and the formation of compounds.

In a computed radiology (CR) system, the image is originally recorded on the phosphor material of the cassette. In CR systems, the patient's X-ray exposure is captured by a cassette containing a phosphor plate. When the cassette is exposed to X-rays, the phosphor material absorbs the energy and stores it as an invisible image. Later, the cassette is placed in a reader, where the stored energy is released and converted into a digital image that can be viewed on a computer. Therefore, the image is initially recorded on the phosphor material of the cassette before being processed and viewed on a computer.

A dual focus x-ray tube contains two filaments. Filaments are used to generate electrons that are accelerated towards the anodes. The anodes then produce the x-ray beam. The dual focus design allows for the production of two different focal spots, which can be used for different imaging purposes. This feature is particularly useful in radiography, where different focal spot sizes are needed to capture fine details or larger areas of the body.

X-rays can penetrate matter because they have high energy and short wavelengths. This allows them to pass through materials that are opaque to visible light, such as human tissue. X-rays are commonly used in medical imaging to create images of bones and internal organs. However, they do not cause radioactivity, have a negative charge, or are visible to the human eye.

A photon is the correct answer because it is defined as the smallest unit of electromagnetic energy. Photons are particles of light and they have no mass or charge. They carry energy and can behave both as particles and waves. When an atom or molecule absorbs or emits energy in the form of light, it does so in discrete packets called photons. Therefore, a photon is the smallest unit of electromagnetic energy.

Electromagnetic energy is the correct answer because it is the type of energy that has a wave-like form. Electromagnetic energy consists of waves of electric and magnetic fields that travel through space. It includes various forms of energy such as visible light, radio waves, microwaves, and X-rays. These waves have both electric and magnetic components that oscillate perpendicular to each other and to the direction of wave propagation, creating a wave-like form. Therefore, electromagnetic energy fits the description provided in the question.

X-rays have the shortest wavelength among the given options. X-rays have very high energy and short wavelengths, which allows them to penetrate matter easily. This property makes them useful in medical imaging and industrial applications. Radio waves, microwaves, and UV light have longer wavelengths compared to x-rays.

A collimator is a boxlike device attached to the x-ray tube that allows the radiographer to adjust the x-ray field size. It is used to restrict the x-ray beam to a specific area of interest and minimize unnecessary radiation exposure to the patient. By adjusting the collimator, the radiographer can control the size and shape of the x-ray beam, ensuring that only the desired area is exposed to radiation. This helps in obtaining clear and accurate images while reducing the risk of unnecessary radiation dosage.

A grid is a device used to protect the IR (image receptor) from scatter radiation. Scatter radiation is unwanted radiation that can cause fogging on the IR, reducing image quality. A grid consists of lead strips or plates that are placed between the patient and the IR. It allows primary radiation (the radiation that passes straight through the patient) to reach the IR while absorbing or redirecting scatter radiation. This helps to improve image contrast and clarity by reducing the amount of scatter radiation reaching the IR.

The correct answer is 40 - 125 kVp. This range of kilovolt potential (kVp) is required for x-ray production. X-rays are produced when high-energy electrons collide with a metal target, and the energy of the electrons is determined by the kVp. The range of 40 - 125 kVp is commonly used in medical imaging to produce x-rays of varying energies, which are suitable for different types of examinations and imaging techniques.

MRI (Magnetic Resonance Imaging) does not use radiation to create images. Instead, it uses a strong magnetic field and radio waves to generate detailed images of the body's internal structures. This non-invasive imaging technique is particularly useful for visualizing soft tissues, such as the brain, muscles, and organs, without exposing the patient to ionizing radiation.

The quality factor of an x-ray beam refers to the penetrating power or energy level of the beam. The kilovoltage peak (kVp) is a measure of the maximum voltage applied to the x-ray tube during an exposure, which directly affects the energy of the x-ray photons produced. By adjusting the kVp, the radiographer can control the quality or energy level of the x-ray beam. Therefore, the kVp is the correct answer as it directly relates to the quality factor of the x-ray beam.

The correct answer is 1, 2 & 3. Electric current, solids, and gases are all forms of matter. Electric current is the flow of electric charge through a conductor, and it consists of moving electrons or ions. Solids are a state of matter that have a definite shape and volume, with particles that are closely packed together. Gases are a state of matter that have no definite shape or volume, with particles that are spread out and move freely. Therefore, all three options are correct forms of matter.

The correct answer is "tube port". The tube port refers to the opening in the tube housing through which the primary x-ray beam exits. This is the pathway through which the x-ray beam travels from the x-ray tube to the patient and then to the image receptor (IR).

Tungsten is used to make x-ray tube components because it has a high melting point and a high atomic number. The high melting point of tungsten allows it to withstand the high temperatures generated in the x-ray tube. Additionally, the high atomic number of tungsten makes it an effective material for stopping and absorbing x-ray radiation. The shiny appearance of tungsten is not relevant to its use in x-ray tube components.

Protons are positively charged particles found in the nucleus of an atom. They have a positive electrical charge, which is equal in magnitude but opposite in sign to the negative charge of an electron. Neutrons are neutral particles, while electrons are negatively charged. Ions can be positively or negatively charged depending on whether they have gained or lost electrons.

The central ray refers to an invisible line in the center of the x-ray beam that is perpendicular to the long axis of the x-ray tube. It is the main component of the x-ray beam and is responsible for delivering the radiation to the patient or imaging receptor. The central ray plays a crucial role in determining the quality and accuracy of the x-ray image.

An invisible x-ray image that has not yet been processed is called "latent." This term refers to the image being present but not yet visible or developed. It implies that the image is hidden or concealed until it undergoes processing to become visible. The other options, "manifest," "visible," and "ghost," do not accurately describe an x-ray image that has not been processed yet.

The high voltage circuit is responsible for supplying the x-ray tube with the high voltage required to create x-rays. This circuit is responsible for generating the necessary electrical potential difference between the anode and the cathode, which accelerates the electrons towards the target, resulting in the production of x-rays. Without the high voltage circuit, the x-ray tube would not receive the necessary voltage to generate x-rays.

The two exposure controls mentioned in the options are "roter/prep control" and "exposure control". The "roter/prep control" refers to a control mechanism that adjusts the rotation and preparation of the X-ray tube, while the "exposure control" is responsible for regulating the amount of radiation emitted during an X-ray procedure. These controls are essential in ensuring the correct dosage and quality of X-ray images while minimizing patient exposure to radiation.

Attenuation refers to the process of reducing the intensity or strength of x-rays as they pass through the tissues of the body. When x-rays interact with the atoms in the tissues, they can be absorbed, scattered, or transmitted. In the case of attenuation, some of the x-rays are absorbed by the tissues, leading to a decrease in their intensity. This absorption is influenced by factors such as the density and composition of the tissues. Therefore, attenuation is the correct term to describe the absorption of x-rays by tissues.

Primary radiation refers to the radiation that exits the tube and strikes the patient directly without any interaction or scattering. It is the initial beam of radiation that is emitted from the source and travels in a straight line towards the patient. This radiation is of high energy and intensity, and it is the main source of radiation used in medical imaging procedures.

The x-ray tube is made of pyrex glass because pyrex glass is a type of borosilicate glass that has excellent thermal and chemical resistance. This makes it ideal for containing the high temperatures and corrosive environments found in an x-ray tube. Additionally, pyrex glass has low thermal expansion, which helps to prevent cracking and ensures the tube's durability.

The x-ray tube protective housing is made of lead because lead is a dense material that effectively absorbs and blocks radiation. It is commonly used in radiation shielding applications due to its high atomic number and ability to attenuate x-rays. The lead housing helps to protect both the operator and the surrounding environment from unnecessary exposure to radiation.

The control booth is the area in the exam room where the radiographer stands while making x-ray exposures. It is protected by a lead wall to shield the radiographer from radiation exposure. The control booth allows the radiographer to operate the x-ray equipment and control the settings while being safely shielded from the radiation. The other options, such as the transformer cabinet, tube port, and bucky, do not provide the same level of protection for the radiographer and are not specifically used for making x-ray exposures.

The filament is the correct answer because it is responsible for emitting electrons in an x-ray tube. When a high voltage is applied to the filament, it heats up and releases electrons through a process called thermionic emission. These electrons are then accelerated towards the anode, where they interact with the target material to produce x-rays. Therefore, the filament serves as the source of electrons in an x-ray tube.

Scatter radiation refers to the radiation that is deflected from its original path and scatters in different directions. In the context of medical imaging, scatter radiation is primarily caused by interactions between the X-ray beam and the patient's body tissues. As X-rays pass through the patient, they can be scattered in various directions, leading to unwanted exposure to radiation for both the patient and the healthcare personnel. Therefore, the patient is the main source of scatter radiation in this scenario.

Fog refers to the unwanted image exposure caused by scatter radiation. When X-rays pass through the body, some of them are scattered, leading to a loss of image clarity. This scattering creates a hazy appearance on the X-ray film or image, which is commonly referred to as fog. It can obscure important details and reduce the overall quality of the image, making it harder for medical professionals to accurately diagnose and interpret the X-ray.

The stream of electrons that moves from the cathode to the anode during x-ray exposure is referred to as the tube current. This current is responsible for generating the x-rays that are used for imaging purposes. It is an essential component in the x-ray tube, as it enables the production of the necessary energy to create the x-ray beam.

Atoms are the smallest units of matter and are considered the building blocks of all matter. They are composed of protons, neutrons, and electrons. Atoms combine together to form molecules, which in turn combine to form cells, the basic units of life. Therefore, atoms are the fundamental components from which all matter is made, making them the correct answer.

Electrons are particles found in orbits surrounding the nucleus of an atom. They have a negative charge and are much smaller in mass compared to protons and neutrons. Electrons are responsible for the chemical behavior of atoms and are involved in the formation of chemical bonds.

A physician who interprets medical images and performs radiographic procedures is referred to as a radiologist. Radiologists are medical doctors who specialize in diagnosing and treating diseases and injuries using medical imaging techniques such as X-rays, CT scans, MRI scans, and ultrasound. They are trained to interpret the images and provide accurate diagnoses based on their findings. Radiographers, technologists, and X-ray techs are also involved in performing radiographic procedures, but they do not have the same level of medical training and expertise as radiologists.

The given answer, mAs, refers to milliampere-seconds, which is a measure of the quantity or amount of x-ray radiation produced. It represents the product of the tube current (measured in milliamperes) and the exposure time (measured in seconds). Increasing the mAs value increases the number of x-ray photons produced, resulting in a higher quantity or intensity of the x-ray beam. Therefore, mAs is considered the quantity factor of the x-ray beam.

Filtration is used in radiography to reduce patient dose by removing low-energy x-rays that are not useful for image formation. These low-energy x-rays contribute to patient dose without adding any valuable information to the image. By reducing patient dose, filtration helps to minimize the potential harmful effects of radiation exposure while still producing high-quality radiographic images. Therefore, the correct answer is to reduce patient dose.

The American Registry of Radiologic Technologists (ARRT) is the organization that certifies individuals who successfully complete an exam in radiography. They are responsible for setting the standards and requirements for certification in the field of radiography, ensuring that individuals have the necessary knowledge and skills to practice safely and effectively. The ARRT certification is widely recognized and respected in the industry, and it demonstrates a high level of competence and professionalism in the field of radiography.

Ionization is the process by which an atom gains or loses an electron. When an atom gains an electron, it becomes negatively charged and is called an anion. Conversely, when an atom loses an electron, it becomes positively charged and is called a cation. This process is essential in many chemical reactions and plays a crucial role in the formation of compounds. Therefore, the correct answer is electron.

Tungsten is commonly used as the target material in X-ray tubes because it has a high melting point and can withstand the high temperatures generated during X-ray production. Additionally, tungsten has a high atomic number, which means it is effective at producing X-rays with high energy and penetrating power. This makes tungsten an ideal choice for producing high-quality X-ray images.

Thermionic emission refers to the process of releasing electrons from a heated material. In the context of x-ray exposure, thermionic emission provides a source of electrons. These electrons are released from a heated filament and accelerated towards a target, creating the x-rays. Therefore, the correct answer is "source of electrons."