DH 1050 quiz 2

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DH 1050 quiz 2
2014-10-04 18:52:11
first lecture

first lecture
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  1. Radiation is the emission and propogation of energy through space or a substance in the form of waves or particles.  Radioactivity can be defined as the process by which certain unstable atoms or elements undergo spontaneous disintegration of decay in an effort to attain a more balanced neuclear state

    true false
    false true
    true true
    true and true
  2. Which component of the tubehead aims and shapes the x-ray beam
    the PID (position indicating device)
  3. Within the x-ray tube electrons are generated by what:
    • your tungsten filament in the cathode
    • No filament in the anode just a tungsten target
  4. The purpose of the anode is to what
    our electrons start over in the cathode they shoot over to the anode and the tungsten target converts those electrons into photons
  5. Which form of the x-ray beam is most detrimental to the patient and operator:
    scatter radiation
  6. Which of the following four possibilities that can occur when an x-ray photon interacts with matter is responsible for producing densities on film that make dental radiography possible
    no interaction that x-ray photon is going straight through hitting that film and that’s what is causing the densities on the film.
  7. When kVp is increased what happens
    we get a higher energy x-ray beam and we have an increased pentrating ability
  8. A film with low contrast is what
    • has lots of shades of grey we as hygiensts like this.  High contrast means there’s lots of
    • white and lots of dark and that’s what dentists like.  It detects periodontal disease and has lots of shades of grey (low contrast this is the answer)
  9. mA regulates the what
    quantity of electrons
  10. using 12 mA  with the exposure of 1 second will result in 12 mA if the mA is decrease to 8 the time must be increased by how much to maintain the same density on the radiograph
    1.5  - 12mA * 1sec = 12 mA how are going to still maintain the 12 mA if  12/8 = 1.5 so 1.5 is how much increased to keep same 12mA
  11. a dental hygienst changes the mA and  maintains the kVp and impulses of the x-ray machine at the same setting which of following image characterists will be effected
    density (density is the overall blackness we know if we increase our mA it will cause our film to be more dark and so it’s going to have increased density
  12. Approximately what percentage of electron energy in the tubehead is converted to x-rays
    one percent
  13. Collimation of the x-ray beam serves to do what
    reduces the diameter of the primary  x-ray beam and (actually 70% reduction in radiation to our patient)
  14. Radiographic intensifying screens are used to what
    reduces exposure time on patient
  15. Protection from  excessive exposure to radiation is aided by the use of aluminum filters and lead diaphram.  The filters reduce the amount of soft radiation reaching the patientsface and the diaphram controls the area exposed

    true true
    false true
    true false
    true true
  16. Increasing the mA while maintaining the kVp exposure time and film speed will result in what
    increased quantity of generated x-rays
  17. For x-ray timers calibrated in impulses how many of those impulses are in one second
  18. If a source to film distance were increased without changing the mA exposure time what would happen to our radiograph
    it would be lighter because those photons have a longer distance to travel
  19. Secondary, or scatter radiation, originates when what happens
    x-rays strike matter (that’s why we protect our patients and hide around a wall for ourselves)
  20. Use of which of the following results in the greatest reduction of radiation to the patient
    the film with the fast emulsion speed