Physics Flashcards
Which cell type is the most radiosensitive in the body?
a. erythrocyte
b. lymphocyte
c. megakaryocyte
d. monocyte
e. neutrophil
Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p516.
b. lymphocyte
How many half-value layers represent the equivalent of one tenth-value layer?
a. 1.5
b. 2.2
c. 2.75
d. 3.3
e. 5
Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p547.
d. 3.3
Which form of leukemia is not considered to be a form of radiation induced leukemia?
a. acute lymphocytic
b. acute myelogenous
c. chronic lymphocytic
d. chronic myelogenous
e. none of the above
Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p529.
c. chronic lymphocytic
Which represents a nearly tissue-equivalent radiation dosimeter? a. calcium fluoride b. calcium sulfate c. calcium tungstate d. lithium borate e. lithium fluoride Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p565.
e. lithium fluoride
True or false:
Teleradiology is the process of remote transmission and viewing of images.
Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p330.
True
True or false: Distortion is reduced by positioning the anatomical part of interest perpendicular to the plane of the image receptor. a. false b. true Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p252.
False
- The 5% rule describes that an increase of kVp by 5% can be accompanied by a decrease in mAs by what percent?
a. 5
b. 15
c. 30
d. 50
e. 66
Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p250.
c. 30
A 15% increase in kVp accompanied by how much of a reduction in mAs creates the same optical density? a. 1/10 b. 1/5 c. ¼ d. 1/3 e. ½ Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p248.
½
True or false:
A long exposure time reduces motion blur?
Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p238.
False
True or false:
Silver sulfide stain is the most common cause of poor archival quality.
Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p231.
True
Scatter radiation increases as the x-ray field size _______.
a. decreases
b. increases
Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p189.
increases
There is a decrease in patient dose and an improvement in contrast resolution when collimation is _______.
a. large
b. small
small
Compression of anatomy ______ spatial resolution. a. improves b. worsens Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p190.
improves
The focal spot blur is ______ on the anode side of the image.
a. large
b. small
Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p178.
small
Image receptors with a wide latitude have a _____ grayscale. a. long b. short Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p172.
long
X-rays with energy of 15 MeV is capable of which interaction with matter?
a. coherent scatter
b. Compton effect
c. pair production
d. photodisintegration
e. photoelectric effect
Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p153.
photodisintegration
The description of the photoelectric effect earned who the Nobel prize? a. Dally b. Edison c. Einstein d. Hounsfield Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p149.
Einstein
Beam hardening refers to a relative ______ in average energy.
a. decrease
b. increase
Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p131.
increase
Which type of x-rays form a continuous emission spectrum?
a. bremsstrahlung
b. characteristic
Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p128.
bremsstrahlung
True or false:
Most x-rays in the diagnostic range are bremsstrahlung.
Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p127.
True
True or false:
Ferromagnetic materials can become magnets by induction.
Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p73.
True
True or false:
Magnetic susceptibility is the degree to which a material can be magnetized.
Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p72.
True
True or false:
The amount of transmitted photons increases as attenuation increases.
Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p53.
False
True or false:
Gamma rays are emitted from an electron cloud that has been artificially stimulated.
Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p51.
False
Which is not a part of the electromagnetic spectrum?
a. gamma rays
b. microwaves
c. radiofrequency
d. ultrasound
e. x-rays
Bushong, Stewart. Radiologic Science for Technologists. 11th ed. p49.
ultrasound
Energy emitted and transferred through space best describes
a. excitation
b. frequency
c. ionization
d. magnetization
e. radiation
Bushong, S. C. (2017). Page 5
radiation
The removal of an electron from an atom describes
a. excitation
b. frequency
c. ionization
d. magnetization
e. radiation Bushong, S. C. (2017). Page 5
ionization
Which is an electromagnetic radiation form which can ionize?
a. infrared light
b. microwaves
c. visible light
d. radiowaves
e. x-rays
Bushong, S. C. (2017). 11th ed Page 6
x-rays
Which is a way to protect x-ray equipment operators from radiation exposure?
a. appropriate film-screen combination
b. collimation
c. filtration
d. shielding
e. using a high kVp
Bushong, S. C. (2017). 11th ed. Page 605
shielding
The risk of childhood leukemia is increased by what percentage if a fetus is irradiated in utero?
a. 20%
b. 30%
c. 40%
d. 50%
e. 60%
Bushong, S. C. (2017). 11th ed. Page 536
50%
What is the genetically significant dose value in the United States?
a. 100rem
b. 100mSv
c. 150mGy
d. 200rad
e. 200mGy
Bushong, S. C. (2017). 11th ed. Page 572
200mGy
Which type of leukemia is not considered a radiation induced leukemia?
a. acute lymphocytic leukemia
b. acute myelogenous leukemia
c. chronic lymphocytic leukemia
d. chronic myelogenous leukemia
Bushong, S. C. (2017). Radiologic science for technologists: Physics, biology, and protection. St. Louis, MO: Elsevier. Page 529
chronic lymphocytic leukemia
Permanent epilation occurs with radiation doses of
a. 2Gy
b. 5Gy
c. 7Gy
d. 9Gy
e. 10Gy
Bushong, S. C. (2017). Radiologic science for technologists: Physics, biology, and protection, pg. 513
7Gy
Which radiation dose-response relationship is described as having a response which is directly proportional to the dose?
a. linear
b. non-linear
c. threshold
d. non-threshold
Bushong, S. C. (2017). Radiologic science for technologists: Physics, biology, and protection. St. Louis, MO: Elsevier. Page 487
linear
Which radiation dose - response relationship suggests that any dose is expected to produce a response?
a. linear
b. non-linear
c. threshold
d. non-threshold
Bushong, S. C. (2017). Radiologic science for technologists: Physics, biology, and protection. St. Louis, MO: Elsevier. Page 488
non-threshold
Rayleigh-Tyndall scattering in sonography is due to
a. an inadequate Fresnel zone.
b. an enlarged Fraunhoffer zone.
c. inadequate transducer contact.
d. the presence of calcium in the visualized
anatomy.
e. red blood cells.
Curry, T. S. Dowdey, J. E. Murray, R. C. (1990). Christensen’s Physics of Diagnostic Radiology. 4th ed. Malvern, PA: Lea & Febiger. Page 355.
red blood cells
The CT characterized by a rotating x-ray tube and a couch which moves the patient through the rotating beam describes a
a. first generation CT.
b. second generation CT.
c. third generation CT.
d. multislice helical
CT. Bushberg, J. T. Seibert, J. A. Leidholdt, E. M. Boone, J. M. The Essential Physics of Medical Imaging. (2012. 3rd. ed. Philadelphia, PA: Lippincott Williams & Wilkins. Page 337.
multislice helical CT.
Ring artifacts are seen on CT images due to the use of a rotate-rotate scanner. This scanner was seen in which generation of CT?
a. first generation CT
b. second generation CT
c. third generation CT
d. fourth generation
Curry, T. S. Dowdey, J. E. Murray, R. C. (1990). Christensen’s Physics of Diagnostic Radiology. 4th ed. Malvern, PA: Lea & Febiger. Page 320.
third generation CT
The relationship between the patient couch movement and the x-ray beam width in CT is known as the
a. interpolation.
b. gantry ratio.
c. piezoelectric effect.
d. pitch.
e. Q factor.
Bushberg, J. T. Seibert, J. A. Leidholdt, E. M. Boone, J. M. The Essential Physics of Medical Imaging. (2012. 3rd. ed. Philadelphia, PA: Lippincott Williams & Wilkins. Page 338.
pitch
The purity of sound and length of time sound persists with regard to the crystal in an ultrasound transducer is known as the
a. interpolation.
b. gantry ratio.
c. piezoelectric effect.
d. pitch.
e. Q factor.
Curry, T. S. Dowdey, J. E. Murray, R. C. (1990). Christensen’s Physics of Diagnostic Radiology. 4th ed. Malvern, PA: Lea & Febiger. Page 330.
Q factor.
What is cinefluorography most commonly used to image?
a. bones
b. bowel
c. brain
d. heart
e. lungs
Curry, T. S. Dowdey, J. E. Murray, R. C. (1990). Christensen’s Physics of Diagnostic Radiology. 4th ed. Malvern, PA: Lea & Febiger. Page 189.
heart
How can motion blur be avoided when taking radiographs of a patient?
a. decreasing kVp
b. increasing exposure time
c. using a large OID
d. using a small SID
e. using a breath hold
Bushong, S. C. (2017). Radiologic science for technologists: Physics, biology, and protection. Page 181
using a breath hold*
How can penumbra be reduced when taking radiographs?
a. decreasing kVp
b. decreasing SID
c. increasing mAs
d. increasing OID
e. using a small focal spot
Curry, T. S. Dowdey, J. E. Murray, R. C. (1990). Christensen’s Physics of Diagnostic Radiology. 4th ed. Malvern, PA: Lea & Febiger. Page 225.
using a small focal spot
Which step of radiographic film processing removes unexposed silver halide crystals?
a. development
b. drying
c. fixing
d. stop bath
e. washing
Bushong, S. C. (2017). Radiologic science for technologists: Physics, biology, and protection. St. Louis, MO: Elsevier. Page 230
fixing
A 20-year-old radiographic film has turned a yellow-brown color. What is the most likely cause?
a. expiration of developing agents
b. fixer retention
c. inadequate developing
d. normal film aging
e. oxidation of the developer
Bushong, S. C. (2017). Radiologic science for technologists: Physics, biology, and protection. St. Louis, MO: Elsevier. Page 231
fixer retention
The silver halide in the radiographic film emulsion layer is mostly made of
a. silver bromide
b. silver iodide
c. silver nitrate
d. silver oxide e. silver sulfide
Bushong, S. C. (2017). Radiologic science for technologists: Physics, biology, and protection. St. Louis, MO: Elsevier. Page 209
a. silver bromide
Fixer retention leads to the development of which compound?
a. silver bromide
b. silver iodide
c. silver nitrate
d. silver oxide
e. silver sulfide
Bushong, S. C. (2017). Radiologic science for technologists: Physics, biology, and protection. St. Louis, MO: Elsevier. Page 231
e. silver sulfide
Which is true regarding the performance of the air-gap technique during radiographic examination?
a. kVp should be increased by 25% for every 1cm
increase in OID
b. mAs must be increased by 10% for every 1cm
increase in OID
c. mAs must decrease by a factor of 2 for every
2cm increase in OID
d. no changes are needed in kVp or mAs
e. The technique can only be used with a kVP
greater than 100.
Bushong, S. C. (2017). Radiologic science for technologists: Physics, biology, and protection. St. Louis, MO: Elsevier. Page 204
b. mAs must be increased by 10% for every 1cm increase in OID
If a patient is properly exposed at 40 inches SID with a mAs of 20 what must the mAs be if the SID is changed to 72 inches?
a. 35
b. 50
c. 60
d. 65
e. 70
Bushong, S. C. (2017). Radiologic science for technologists: Physics, biology, and protection. St. Louis, MO: Elsevier. Page 240
d. 65
To prevent a female accidentally exposing an embryo to radiation during the early stages of pregnancy, the radiographer should _______________.
a. only irradiate her during the last 10 days of her menstrual period
b. never irradiate a female for any reason
c. do it whenever, because it isn’t that much radiation
d. only irradiate her during the first 10 days of her menstrual period
d. only irradiate her during the first 10 days of her menstrual period
When x-raying females, the radiographer is expected to:
a. employ the stochastic principle
b. follow the 10 day rule
c. use only high LET radiation
d. do all of the above
b. follow the 10 day rule
The number of photons in the beam is influenced by_______________.
a. mA
b. Time
c. kVp
d. all of the above
d. all of the above
Which of the following influences the photon energy of the beam?
a. mA b. Time c. kVp all d. of the above
c. kVp
The uneven distribution of radiation from one end of the x-ray field to the other is due to the _______.
a. line focus principle
b. inverse square law
c. heel effect
d. larger anode angle
c. heel effect
Which of the following is NOT a method for reducing the production of scatter radiation?
a. Patient compression
b. Beam restricting device
c. Having the patient lie down
d. Increasing the mAs
d. Increasing the mAs
Which of the following is NOT a method of restricting the x-ray beam?
a. Cone
b. Aperture
c. Grid
d. Positive beam limiting device
c. Grid
________________ is the principle disadvantage of using an aperture to limit the size of the x-ray field.
a. Large penumbra
b. Decreased kvp
c. Being too simple a device
d. Because it can only be used at a large FFD
a. Large penumbra
The best method for restricting x-ray field size is the ______________.
a. aperture
b. collimator
c. cone
d. cylinder
b. collimator
A positive beam limiting device is ____________.
a. an automatic collimator
b. an automatic grid
c. a form of cylinder
d. any form of beam restrictor
a. an automatic collimator
A device that shows a light on the patient in order to aim the x-ray beam and also serves to limit the size of the x-ray field is called a ___________.
a. grid
b. collimator
. cone
d. bucky
b. collimator
Modern collimators have two sets of shutters in each direction for what purpose?
a. Prevent shoot-through by the primary beam
b. Redundancy in case one set fails
c. Clean up penumbra
d. All of the above are correct
c. Clean up penumbra
If you wanted to test the accuracy of your collimator, which test would you perform?
a. Mesh screen test
b. Bucky’s diagnostic exam
c. Paper clip test
d. Determine the half value layer (HVL)
c. Paper clip test
Radiation effects within the cell are ____________________.
a. definite and predictable
b. selective and definite
c. selective and indefinite
d. random and non-selective
d. random and non-selective
(Stochastic)
The biologic effects of radiation that occur in living cells are __________.
a. always immediate
b. unique to radiation damage
c. always after some latent period
d. usually delayed only a few seconds
c. always after some latent period
The direct effects of radiation include:
a. damage to DNA
b. radiolysis of water
c. production of free radicals
d. none of the above
a. damage to DNA
Which of the following molecules in the cell are most sensitive to radiation?
a. Protein
b. DNA
c. Enzymes
d. All of these are equally sensitive
b. DNA
The interaction of a photon with water producing a free radical to damage the internal portions of a cell is _________________.
a. a form of indirect damage
b. direct damage
c. a normal process
d. none of the above
a. a form of indirect damage
Regarding the indirect mechanism of cellular radiation damage, in which stage do free radicals react to form new molecules?
a. Physical stage
b. Physio-chemical stage
c. Chemical stage
d. Biologic stage
c. Chemical stage
The rate at which energy is deposited into matter by radiation is the __________.
a. SED
b. LET
c. RAD
d. Roentgen
b. LET
The principle that states the younger immature cells are most radiosensitive is _______.
a. Law of Bergonie & Tribondeau
b. Law of Bergman & Bordeaux
c. Gray & Sievert
d. Kassabian & Dally
a. Law of Bergonie & Tribondeau
Which of the following is NOT an effect on the embryo & fetus from radiation?
a. Lethality
b. Congenital abnormality
c. Long term effects that develop in life
d. All of the above are effects of radiation
d. All of the above are effects of radiation
An embryo is most sensitive to death if exposed to radiation during which stage of development?
a. Major organogenesis
b. Fetal stage
c. Pre-implantation
d. Vegetative-intermitotic stage
c. Pre-implantation
The effects of irradiation during the fetal stage are usually:
a. lethal
b. congenital abnormality
c. retinoblastoma
d. sterility & other late effects
d. sterility & other late effects
An effect in which the probability of occurance increases with increasing absorbed dose, but the severity of the effect does not increase with dose is defined as:
a. stochastic effect
b. non-stochastic effect
c. law of Bergonie & Tribondeau
d. Non-random event
a. stochastic effect
A somatic effect that increases in severity with increasing absorbed dose is known as a ______________ effect.
a. stochastic
b. non-stochastic
c. random
d. characteristic
b. non-stochastic
Of the following, which one is considered a stochastic effect?
a. Genetic alteration
b. Lens opacification
c. Blood changes
d. Decreased sperm production
a. Genetic alteration
The paper clip test will determine _______________________.
a. the screen film contact
b. focal spot size
c. grid cutoff
d. proper collimator alignment
d. proper collimator alignment
Which form of beam restriction has an extended metal tube structure to limit the size of the x-ray field?
a. Aperture diaphragm
b. Cylinder
c. Collimator
d. All of the above
b. Cylinder
CT utilizes what to create its images?
a. A big magnet
b. Technetium 99
c. X-rays
d. None of the above
c. X-rays
In CT imaging, the setting of how the gray scale is displayed for reading is called, what?
a. Windowing
b. Weighting
c. Withering
d. Contrasting
a. Windowing
According to what was said in class, which form of imaging is preferred for seeing fractures of the posterior elements of the spine?
a. MRI
b. CT
c. Bone scanning
d. Radiography
b. CT
A darkroom is used to process film, for what reason?
a. To refrigerate the latent image until processed
b. To make enough fog for a well exposed film
c. To prevent fogging of the film by other radiation or visible light
d. None of the above
c. To prevent fogging of the film by other radiation or visible light
Which statement about film fog is TRUE?
a. Fog is desirable for adequate density
b. Fog is created by complete darkness and controlled temperatures
c. Fog can be removed by the film processor
d. Fog contributes to image noise and is undesirable
d. Fog contributes to image noise and is undesirable
True or False
A safelight can fog film.
True
Which of the following is NOT used in making a darkroom light tight?
a. Maze
b. Revolving door
c. Window
d. Weather stripping
c. Window
Of the following, which is NOT a requirement for a radiographic darkroom?
a. Safelight
b. Overhead light
c. Film storage bin
d. Viewbox
d. Viewbox
Which of the following is a variable that affects film detail?
a. ma
b. kvp
c. time
d. focal spot size
d. focal spot size
The effective focal spot appears smaller than the actual focal spot because of __________.
a. the line-focus principle
b. the heal effect
c. the object-film distance
d. grid ratio
a. the line-focus principle
-
Line focus principle explains the relationship between the anode surface and the effective focal spot size.
- The focal spot is the area of the target upon which the electron beam impinges. The energy of the electrons in the electron beam is mostly converted into heat (approx 99% ) and dissipated uniformly across the focal spot and anode surface.
- The x-rays produced at the anode comprise of less than one percent of the energy of the electrons in the electron beam.
- A large focal spot is useful to protect the tungsten target as the heat accumulates and dissipates within the area of focal spot. However, a small focal spot is required to achieve a good radiographic image quality
Thus the line focus principle helps resolve this issue by stating that an angulation of the anode surface will result in an apparent decrease in the focal spot size.
The region at the edge of an object that appears unsharp (less detailed) because the many x-ray “point sources” from the focal spot overlap there is called what?
a. Line focus principle
b. Heel effect
c. Penumbra
d. Umbra
c. Penumbra
To calculate the size of the focal spot, which test would you perform?
a. Resolution chart
b. Star diagram
c. Slit test
d. Pinhole test
d. Pinhole test
What is the most common type of distortion?
a. Foreshortening
b. Elongation
c. Motion
d. None of the above
b. Elongation
In order to minimize magnification on an image, you would do which of the following?
a. Decrease OFD, and decrease FFD
b. Decrease OFD, and increase FFD
c. Increase OFD, and decrease FFD
d. Increase OFD, and increase FFD
b. Decrease OFD, and increase FFD
Which of the following is a TRUE statement about the geiger counter?
a. It is good for detecting particulate radiation
b. It permanently stores a count of all radiation encountered
c. It uses a gas filled tube and is portable
d. It determines the energy level of encountered radiation
c. It uses a gas filled tube and is portable
A TLD is a detector that ______________.
a. uses fluorescence
b. is a pocket dosimeter
c. has a higher voltage than the geiger counter
d. All of the above are true about the TLD
a. uses fluorescence
The type of radiation dose monitoring device that measures the total blackness of a piece of film is called a _____________.
a. TLD
b. film badge
c. pocket geiger
d. film shield
b. film badge
With regard to ionization chambers, the greater the voltage _______________.
a. the greater the specificity
b. the less the sensitivity
c. the greater the sensitivity
d. the less the specificity
c. the greater the sensitivity
The principle disadvantage of using an air-gap technique is:
a. increased dose
b. decreased FFD
c. increased kVp
d. increased OFD
d. increased OFD
Electrical current is measured in __________.
a. Volts
b. Amperes
c. Roentgens
d. Ohms
b. Amperes
Substances that permit the easy flow of electrons are ____________.
a. insulators
b. shells
c. ionizers
d. conductors
d. conductors
Glass is an example of, what?
a. A substance that easily permits electrons to travel. b. A substance that does not easily permit electrons travel.
c. An anode target material.
d. A low resistance material.
b. A substance that does not easily permit electrons travel.
Electrical resistance is governed by ______________.
a. Ohm’s law
b. Planck’s constant
c. Grenz principle
d. Boyle’s law
a. Ohm’s law
The difference in electrical potential as measured at different points of a circuit is called the _________________.
a. amperage
b. power
c. voltage
d. resistance
c. voltage
An electrical current that oscillates between two directions is called, what?
a. Direct current (DC)
b. Alternating current (AC)
c. A rock band (AC/DC)
d. Transformed
b. Alternating current (AC)
A device that converts AC to DC is called a ______________.
a. rectifier
b. alternator
c. director
d. transformer
a. rectifier
How are heat units of an x-ray tube determined?
a. Volts x resistance x watts
b. Volts x Amps x watts
c. Seconds x Volts x resistance
d. Volts x Amps x seconds
d. Volts x Amps x seconds
The variation of voltage from its maximum value to some lower percentage is called, what?
a. Phase
b. Wavelength
c. Frequency
d. Ripple
d. Ripple
A diode is used to, what
a. Accelerate electrons
b. Step-up voltage
c. Rectify current
d. None of the above
c. Rectify current
Copper wire is an example of a(n)
a. capacitor
b. transformer
c. ainsulator
d. conductor
d. conductor
The conversion of current of AC to DC is done with a(n) ______________.
a. transformer
b. rectifier
c. anode
d. converter
b. rectifier
A step up transformer has a turn ratio that is:
a. greater than 1
b. less than 1
c. equal to 1
d. none of the above
a. greater than 1
The curve that represents the relationship of film density and radiation exposure is called the:
a. Compton curve
b. Hunter & Dreyfus curve
c. Rayleigh & Thomson curve
d. Hurter & Driffeld curve
d. Hurter & Driffeld curve
The part of the characteristic curve representing the lightest possible portion is:
a. straight line portion
b. the toe
c. the shoulder
d. the top
b. the toe
Spectral matching refers to:
a. matching of the size of the film to the cassette
b. matching of the color sensitivity of the film with that emitted by the screen
c. matching of the ghost with our car on the haunted mansion ride at Disneyland
d. the dating service you got thrown out of
b. matching of the color sensitivity of the film with that emitted by the screen
The film emulsion is composed of gelatin and holds the light sensitive crystals in suspension. What are the majority of the crystals made of?
a. Silver iodide (AgI)
b. Silver bromide (AgBr)
c. Silver chloride (AgCl)
d. Silver fluoride (AgF)
b. Silver bromide (AgBr)
Modern film is made with a base made of polyester. Before that they were made of, what?
a. Celluose polyvinylchloride
b. Methylmethacrylate
c. Cellulose triacetate
d. Rubber
c. Cellulose triacetate
When something appears to be in two different locations on the film, this is due to ______________.
a. parallax
b. Gurney-Mott hypothesis
c. quantum mottle
d. big trouble in little China
a. parallax
The type of film used in general radiography today is
a. direct exposure film
b. duplicating film
c. screen film
d. latent film
c. screen film
A liberated electron in a silver halide crystal that is trapped by the sensitivity speck forms
a. a development center
b. a conduction band
c. parallax effect
d. All of the above
a. a development center
A film’s sensitivity to light is referred to as its, what?
a. Density
b. Graininess
c. Speed
d. Noise
c. Speed
The ability to visually detect separate objects on a film is called its___________.
a. contrast
b. resolution
c. speed
d. density
b. resolution
The sensitivity speck of a film crystal is central to the ________________.
a. Gurney-Mott hypothesis
b. quantum mottle theory
c. law of Bergonie & Tribondeau
d. None of the above
a. Gurney-Mott hypothesis
See Christtensen’s pg. 140
The theory states that the formation of latent image is d/t metallic silver formed at sensitivity centres located at imperfections in structure of silver halide crystals
What about the H & D curve is responsible for film speed?
a. Straight line
b. Toe
c. Shoulder
d. Position on the X - axis
d. Position on the X - axis
A film that has a lot of contrast has a curve with a:
a. high shoulder
b. low curve
c. long gray scale
d. steep straight line portion
d. steep straight line portion
The minimum total thickness of Al equivalent (in mm) for machines with settings above 70 KVP is:
a. 0.5
b. 1.0
c. 2.5
d. 3.0
c. 2.5
Which of these is NOT a process of attenuation?
a. Photon braking
b. Absorption
c. Scatter
d. Distance
a. Photon braking