Which of the following statements related to radiation is correct?
A. Electromagnetic radiation has only one level of energy.
B. Electromagnetic radiation consists of tiny, slow-moving particles with low energy and no mass.
C. Electromagnetic radiation is mainly pure energy with no mass that travels through space and matter as waves at the speed of light in streams of small "packets" of energy called photons.
D. Electromagnetic radiation is the result of nuclear disintegration.
Which of the following statements related to electromagnetic radiation is correct?
A. Electromagnetic radiation is the only type of ionizing radiation.
B. Non-ionizing electromagnetic radiation has energies <5eV, such as visible light microwaves and radio waves.
C. Ionizing electromagnetic radiation has energies <5eV volts, and it cannot eject electrons from an atom.
D. Non-ionizing and Ionizing electromagnetic radiation have energies >5eV
Which of the following statements related to energy conversion and generation of x-rays is correct?
A. When an electron traveling at high speed strikes a target atom, it will always completely be stopped by the gravitational forces of that atom.
B. Based on the law of conservation of energy, the kinetic energy of the incoming electron cannot be lost and must be absorbed by the atom or converted to another form of energy.
C. About 99% of kinetic energy will be converted into x-ray and the remaining will be converted to heat.
D. A high-speed electron that passes far from the nucleus of the atom of the target will result in emission of a high energy x-ray photon.
Which of the following statements related to the energy level of x-radiation is correct?
A. If the electron is completely stopped by the gravitational forces of an atom, the x-ray energy will be equal to the total kinetic energy of the electron.
B. The electrons that are not completely stopped will not produce any radiation.
C. When one high speed electron interacts with an atom, the result is a continuous spectrum of x-rays varying from very low energies to very high energies.
D. The x-ray spectrum has more high-energy photons.
Which of the following statements related to the generation of x-rays by a Tungsten cathode and anode encased in a Pyrex glass vacuum tube is correct?
A. The anode is used to generate electrons via thermionic emission.
B. A step-up and a step-down transformer is used to transform the regular 110V alternating current to a high voltage at the level of the tube (more than 50 kV), and to a low voltage at the level of the filament (10 V), respectively.
C. A focusing cup houses the anode to prevent the electrons from repelling each other away from the filamet and allow the stream of electrons from cathode to anode to be controlled.
D. Tungsten is used in the cathode but not in the anode.
Which the following statements related to the operation of the x-ray tube is correct?
A. When the x-ray tube is turned on, the high-voltage circuit is activated to preheat the filament to a specific temperature to generate electrons through thermionic emission.
B. The number of electrons generated is inversely proportional to the temperature of the filament.
C. When the timer is activated, the high voltage circuit is also activated and the electrons at the filament will start travelling at high speed towards the target.
D. The lower is the voltage between the cathode and the anode the faster will the electrons travel.
The number of electrons travelling from the cathode to the anode depends on:
A. kVp
B. kVp and mA
C. kVp, mA and exposure time
D. mA and exposure time
Which of the following statements related to the filters in an x-ray tube is correct?
A. Filters absorb the high energy photons from the x-ray spectrum as these high energy photons will not contribute to image formation.
B. In dental x-ray units, the glass of the tube does not act like a filter.
C. In dental x-ray units, a piece of lead is added in front of the x-ray tube for filtration.
D. The total filtration is expressed as an equivalent to millimeter of aluminum.
Which of the following describes the role of a collimator?
A. It is used to reduce the size and change the shape of the X-ray beam, and to reduce the irradiated area in the patient.
B. It is used to reduce the energy of the high-energy photons of the X-ray beam, and to reduce the irradiated area in the patient.
C. It is used to reduce the energy of the low-energy photons of the X-ray beam, and to increase the irradiated area in the patient.
D. It is used to increase the energy of the low-energy photons of the X-ray beam, and to increase the irradiated area in the patient.
Which of the following statements related to the beam indicating device (BID) in an x-ray tube is correct?
A. The BID guides the direction of the x-ray beam during the exposure of dental radiographs.
B. The shape of the BID is always cylindrical.
C. The BID device increases the amount of scattered radiation.
D. The BID device increases the patient's risk of radiation exposure.
Which of the following statements related to the beam quality is correct?
A. Beam quality refers to the overall number of photons emitted by the x-ray tube.
B. A high-quality beam has short wavelength, high mean energy and high maximum energy.
C. The beam quality is controlled by the exposure time which regulates the speed of electrons traveling from the cathode to the anode.
D. When the kVp increases, the resulting x-ray beam is of lower energy and decreased penetrating ability.
Which of the following statements related to the beam quantity is correct?
A. The amperage and the exposure time determine the energy of electrons passing through the cathode filament.
B. An increase in the amperage or in the exposure time will result in an increase in the number of photons generated in the x-ray tube.
C. When amperage is increased, the exposure time must also be increased to maintain the same beam quantity.
D. Since the kilovoltage and the exposure time directly influence the number and energy of photons emitted, they form a common factor called the kiloVolt Peak (kVp).
Which of the following statements related to the beam intensity is correct?
A. Beam intensity is defined as the quality of the beam during exposure relative to a specific area.
B. The intensity of the beam is not affected by the kVp or mAs.
C. The beam intensity is affected by the distance between the x-ray tube and the exposed area such that if the distance is increased, the beam intensity decreases following the inverse square law.
D. If the distance between the source and the area of exposure is doubled, the intensity of the beam will be reduced to 50%.
What happens when the x-ray passes through an absorber (e.g., oral tissues)?
A. It will not be absorbed by what constitutes the absorber regardless of the thickness of each component.
B. It gets differentially absorbed depending on the thickness and density of each of the components of the absorber.
C. It gets differentially absorbed depending on the thickness of each of the components of the absorber regardless of their density.
D. It will not be absorbed by what constitutes the absorber regardless of the density of each component.
Which of the following statements related to x-ray beam intensity is correct?
A. When the x-ray beam exits an absorber (e.g., oral tissues), it will have one level of intensities.
B. The intensity of x-rays exiting an absorber (e.g., oral tissues) will not register on a radiographic receptor.
C. The densities related to a thick absorber (e.g., aluminum or bone) will be darker than the densities of thin absorbers (e.g., soft tissue).
D. The density and thickness of an absorber (e.g., oral tissues) affect the intensity of exiting X-ray beams and determine radiographic contrast.
