Answers in the answer sheet is considered as final.
1. Multiple choice questions.
1. Radiographic contrast is
a. overall degree of darkening of an exposed film.
b. difference in densities between light and dark regions on a radiograph.
c. overall degree of lightening of an exposed film.
d. overall degree of greyness of an exposed film.
2. Bisecting angle technique is that in which
a. central ray is directed perpendicular to the film not the object.
b. central ray is directed perpendicular to the object not the film.
c. central ray is perpendicular to the object and the film.
d. central ray is directed at right angle to the imaginary bisector that bisects the angle between the
long axis of the tooth and the film.
3. Anode of an x ray tube consists of
a. aluminum.
b. filament and focusing cup.
c. heavy metal.
d. tungsten embedded in copper stem.
4. Increasing the focal spot to film distance during an x ray exposure results in
a. more divergent rays.
b. less divergent rays.
c. no effects on the rays projected .
d. no effect on the patient.
5. Filtration is the process of
a. removing low energy x rays from the x ray beam.
b. removing high energy x rays from the x ray beam.
c. reducing the size of the x ray beam.
d. increasing the size of the x ray beam.
6. X rays are produced when
a. electrons from the anode strike the target in the cathode.
b. protons from the cathode strike the target.
c. electrons from the cathode strike the target in the anode.
d. electrons from the cathode strike the beryllium window.
7. Image sharpness can be increased by
a. use as small focal spot , increase the distance between focal spot and object and minimize the
distance between the object and the film.
b. use as large focal spot, decrease the distance between focal spot and object and increase the distance
between the object and the film.
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c. use as large focal spot , increase the distance between focal spot and object and increase the distance
between object and the film.
d. use as small focal spot , decrease the distance between focal spot and object and minimize the
distance between object and the film.
8. Image size distortion can be minimized by
a. decrease the distance between focal spot and film and increase the distance between object and film.
b. increase the distance between focal spot and film and increase the distance between the object and the
film.
c. increase the distance between focal spot and film and decrease the distance between the object
and the film.
d. decrease the distance between focal spot and film and decrease the distance between object and film.
9. Longer the focal spot to film distance will result in
a. less patient protection.
b. more sharp image.
c. less sharp image.
d. more patient protection.
10. For a intraoral x ray machine upto 70 kvp, the total amount of filtration should be
a. 1.5 mm of aluminum.
b. 3 mm of aluminum.
c. 1 mm of lead.
d. 1.5 cm of aluminum.
11. The size of a standard size 2 x ray film is
a. 31 x 41 mm.
b. 22 x 32 mm.
c. 18 x 28 mm.
d. 20 x 30 mm.
12. Which of the following is useful in increasing the sharpness of the image.
a. increase the distance between the object and the film.
b. decrease the distance between the focal spot and object.
c. perpendicular film and object.
d. minimize the distance between the object and the film.
13. The focusing cup
a.
focuses the electrons emitted by the incandescent filament into a narrow beam
directed at a small rectangular area on the anode called the focal spot.
b.
focuses the electrons emitted by the narrow beam directed at a small area on the
cathode .
c.
focuses the electrons from the cathode to the anode.
d.
focuses the electrons from the beryllium window.
14. Increase in the Tube current (mA) results in ,
a.
Increase in the number of photons generated.
b.
Increase in the energy of photons generated.
c.
Decrease in the number of photons generated.
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d.
No change in number & energy of electrons.
15. Indirect effect of radiation damage is by
a.
Ionisation of water molecule with formation of free radicals & hydrogen peroxide.
b.
c.
d.
e.
Effect on the damage of cytoplasm.
No effect
Effect on damage to DNA.
16. A collimator is :
a. used to reduce the size of the x-ray beam and therefore the volume of irradiated tissue within the
patient.
b. used to increase the size of the x-ray beam .
c. used to sharpen the x ray beam.
d. used to prevent x ray beam from reaching the x ray film.
17. Radiographic contrast is
a. differences in densities between light and dark regions on a radiograph.
b. overall degree of darkening of an exposed film.
c. overall degree of lightening of an exposed film.
d. overall degree of greyness of an exposed film.
MORE QS:
1.
When an electrically neutral atom loses an electron , the nucleus becomes a
a. negative ion.
b. positive ion.
c. neutral ion.
d.neutrons.
2. When larger atoms are unstable , they break up releasing
a. light.
b. ions.
c. alpha or beta rays.
d. delta rays.
3. Which of the following densely ionize matter through which they pass.
a.gamma rays.
b. x rays.
c.beta particles.
d. alpha particles.
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4. Beta particles penetrates deeper into the tissue because
a. it carries a single negative charge and have a much lower probability of interacting with matter.
b.it carries a positive charge and has a higher probability of interacting with matter.
c. it carries no charge and facilitates penetration deep into the tissues.
d.its having more mass.
5. The greater the physical size and charge and lower the velocity of a particle
a. the lower is the linear energy transfer.
b. the greater is the linear energy transfer.
c.no change in the ionization energy.
d.no change in the linear energy transfer.
6. The power supply in the x ray machine does the following.
a. heats the copper stem to generate the heat and drive the electrons.
b. heats the target to establish a high voltage potential difference .
c. the tube current boosts the current by increasing the voltage to create a high voltage potential
difference between anode and cathode.
d. heats the cathode filament and establish a high voltage potential between the anode and cathode
to accelerate the electrons towards the anode.
7. The anode of an intraoral x ray machine is called as
a. moving anode.
b. rotating anode.
C. stationary anode.
d. circular anode.
8. Copper in the x ray machine
a. is a good thermal conductor.
b.has high atomic number.
c. has more atomic weight.
d. more efficient in generating high energy x rays.
9. When the exposure time is doubled
a. the energy of photons generated in the x ray spectrum is doubled.
b. the number of photons generated in the x ray spectrum is doubled.
c. no change in the photons generated in the x ray spectrum.
d. the more energy wave is generated.
10. The standard distances between focal spot to object in an intraoral radiography is
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a. 10 cm and 20 cm.
b. 20 cm and 30 cm.
c. 20 cm and 41 cm.
d.20 cm and 51 cm.
11. An intraoral x ray machine operating at 65 kvp will have a filter thickness of
a. 2.5 mm.
b. 2.5 cm.
c. 3 cm.
d. 1.5 mm.
12. The effective focal spot should be
a. as small as possible.
b. as more as possible.
c. perpendicular to the central ray.
d. more so that more x ray photons are generated.
13. The unsharpness in a radiographic image can be increased by
a. minimizing the distance between the focal spot and the object.
b. increasing the distance between the object and the film.
c. minimizing the distance between the object and the film.
d.high voltage target.
14. Ionization energy is
a. electrostatic attraction between the negatively charged nucleus and its surrounding positively charged
electrons.
b.electrostatic attraction when a proton is lost in an atom .
c. when an electon is lost from a neutral atom.
d. electrostatic attraction between the positively charged nucleus and its surrounding negatively charged
electrons.
15. Anything that occupies space:
a. Force
b. Inverse square law
c. Matter
d. Density
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16. Subatomic particles are broken into smaller particles by:
a. Heat waves
b. Electric current
c. Magnetic waves
d. High energy interactions
17. In an atom, the particles revolving around the nucleus is the
a. Orbital electrons
b. Neutrons
c. Positrons
d. Neutrons and protons
18. Neutrons carry:
a. Positive charge
b. Negative charge
c. No charge
d. Double charge
19. In the orbital shell of an atom, the greatest ionization energy contains in the
a. Q shell
b. K shell
c. Incoming photon
d. X-ray
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20. The charge of a proton compared to the charge of an electron is
a. More
b. Less
c. Equal
d. Neutral
21. If an electrically neutral atom loses an electron, the atom is a
a. Positive ion
State true or false and if false correct the underlined word .
1. long source to object distance decreases the x ray exposure rate.
( true).
2. x rays results from radioactive decay of many large atomic number elements.
( false/ alpha particles)
3. visible light and ultraviolet waves types of electromagnetic spectrum rays are non ionizing .
( true)
4. Reducing the distance between the target of the x-ray tube (focal spot) and the teeth makes the beam
less divergent as it passes through the head, exposing a smaller area of the patient. increasing
5. Longer the exposure time reduces the radiation dose which leads to greater amount of damage.
Increases
6. The main purpose of the target in an x ray tube is to convert the kinetic energy of the electrons into
electric current. X ray photons
Fill in the blanks.
1. Dissipating the heat from a small focal spot is done by use of a ___________________.
( rotating anode).
2. The function of the filament transformer in the x ray machine is to __________________________.
( reduce the voltage of the incoming alternating current).
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3. The heat storage capacity for anodes of dental x ray tube is __________.
( 20 KHU)
4. The sudden stopping of high speed electrons by tungsten nuclei in the target produces
_________________________________.
( bremsstrahlung radiation).
5. ________________________ is a measure of the total energy absorbed by any type of ionizing
radiation per unit of mass of any type of matter.
( absorbed dose).
6 .The size of the x ray beam can be regulated by __collimator___.
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Questions from the book:
1. Which statement BEST describes matter?
a. Composed of electrically neutral atoms. b. May be subdivided by chemical methods. c. Anything that
has mass and occupies space. d. Contains inner structures that can be divided.
2. Which nucleus component of the atom determines the identity of the element? a. The number of
quarks. b. The number of protons. c. The number of leptons. d. The number of neutrons.
3. What determines the atomic mass of an atom? a. Force carrier particles. b. Quarks, both up and down.
c. Orbital strength of the electrons. d. Total number of protons and neutrons.
4. The Quantum Mechanical Model describes contemporary understanding of the a. structure of the
nucleus. b. force carrier particles. c. arrangement of electrons in an atom. d. fundamental matter particles
and corresponding antiparticles.
5. Atoms have a maximum number of how many known orbitals? a. 5. b. 7. c. 10. d. 12.
6. Which statement BEST describes the amount of energy required to remove an electron from a given
orbital? a. Exceeds the electrostatic force of attraction. b. Magnitude related to greater distance from
nucleus. c. Lost energy in the form of electromagnetic radiation. d. Lowest principal quantum number,
then lowest angular momentum.
7. The specific balance between the positively charged nucleus and the surrounding negatively charged
electrons is called a. force carrier particles. b. characteristic radiation. c. electron binding energy. d.
electromagnetic radiation.
8. The process resulting in the disruption of the electrical neutrality of the atom is called a. ionization. b.
particulate radiation. c. radioactivity. d. electromagnetic radiation.
9. Loosely bound electrons can be displaced by which low energy radiation? a. Infrared. b. Ultraviolet.
c. Visible light. d. Microwave.
10. Which type of particle is used in the treatment of skin cancers? a. γ. b. χ. c. α. d. β.
11. Linear energy transfer (LET) of particulate radiation refers to a. conversion state. b. rate of loss of
energy. c. ionization capabilities. d. penetration ability of radioactivity.
12. Examples of electromagnetic radiation include all EXCEPT one. Which one is the EXCEPTION? a.
Visible light. b. Radio waves. c. MR imaging. d. Beta particles.
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13. Bundles of energy are called a. photons. b. radioactive. c. wave theory. d. electron volts.
14. The amount of energy acquired by one electron accelerating through a potential difference of 1 volt
is called the a. electron volt. b. linear energy transfer. c. radioactivity potential. d. wavelength to energy
relationship.
15. Which is a property of electromagnetic waves? a. Cause ionization. b. Have mass and weight. c.
Travel at the velocity of light in a vacuum. d. Do not cause biologic changes in living cells.
16. Which unit is typically used to characterize low-energy photons such as radio waves? a. Energy. b.
Direction. c. Frequency. d. Wavelengths.
17. Which are the primary components of an x-ray machine? a. Cathode and anode. b. Tube head and
filters. c. Control panel and collimator. d. X-ray tube and power supply.
18. Which component of the x-ray machine is necessary in order to generate and accelerate electrons? a.
Focal spot. b. Power supply. c. Tube vacuum. d. Focusing cup.
19. Which is the source of electrons within the x-ray tube? a. Anode. b. Filament. c. Control panel. d.
Focusing cup.
20. The number of electrons emitted is determined by the a. thermal conductor. b. high-voltage source.
c. temperature of the filament. d. material composing the filament.
21. The focusing cup is made of a. copper. b. granite. c. tungsten. d. molybdenum.
22. Which is the purpose of the target in an x-ray tube? a. Remove generated heat. b. Stop production of
electrons. c. Convert electrons into x-ray photons. d. Aim the electrons toward the area to be imaged.
23. All are characteristics of ideal target material EXCEPT one. Which one is the EXCEPTION? a. High
melting point. b. High vapor pressure. c. High atomic number. d. High thermal conductivity.
24. Copper and which other component of the x-ray machine tube head dissipates heat? a. Insulating oil.
b. Metal housing. c. Glass envelope. d. Electronic focusing cup.
25. Which is the purpose of a rotating anode? a. Increase production of x-rays. b. Decrease number of
electrons. c. Eliminate need for angled target. d. Dissipate heat from small focal spot.
26. Which type of x-ray machine utilizes a stationary anode? a. Intraoral. b. Tomographic. c.
Cephalometric. d. Medical computed tomography.
27. The flow of electrons from the cathode filament, across the tube to the anode, and then back to the
filament is called the a. voltage. b. tube current. c. x-ray production. d. filament transformer.
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28. Which x-ray machine control regulates the filament temperature? a. On/off switch. b. Exposure time.
c. Milliamperage (mA). d. Kilovolt peak (kVp).
29. Which x-ray machine control converts the primary voltage from the input source into the desired
secondary voltage? a. On/off switch. b. Exposure time. c. Milliamperage (mA). d. Kilovolt peak (kVp).
30. Which is an advantage of a constant-potential x-ray machine over a self-rectifying x-ray machine,
given a voltage and radiographic density setting? a. Lower patient radiation dose. b. Increased radiation
production. c. More efficient use of electricity.d. Effective use of inverse voltage.
31. Which x-ray machine control limits the duration of x-ray production? a. On/off switch. b. Exposure
time. c. Milliamperage (mA). d. Kilovolt peak (kVp).
32. How many impulses of radiation equivalent occur in a one-fourth a. 9. b. 15. c. 20. d. 30.
33. Which is the approximate heat storage capacity for anodes in dental x-ray tubes? a. 5 kHU. b. 15
kHU. c. 20 kHU. d. 30 kHU.
34. Which factor determines the interval between successive x-ray exposures? a. kVp. b. Exposure time.
c. Heat dissipation. d. Number of electrons.
35. Which is the primary form of radiation produced from an intraoral x-ray tube? a. Particulate. b.
Secondary. c. Characteristic. d. Bremsstrahlung.
36. When an electron from the filament directly hits the nucleus of a target atom, which entity is
produced? a. New atom. b. Single x-ray photon. c. Decelerated electron. d. Characteristic radiation.
37. Which statement does NOT explain the continuous spectrum of x-ray photons? a. Accelerated
electrons form characteristic radiation. b. Deflected electrons give up varying amounts of energy. c.
Electrons striking the target have varying levels of kinetic energy. d. Electrons participate in many
bremsstrahlung interactions before losing all their kinetic energy.
38. Which occurs when an electron is ejected from its orbital by an incident electron? a. Particulate
radiation. b. Secondary radiation. c. Characteristic radiation. d. Bremsstrahlung radiation.
39. Doubling the exposure time will result in which occurrence? a. Doubling the range of photon
energies. b. Doubling the number of photons generated. c. Decreasing by half the x-ray emission
spectrum. d. Decreasing by half the number of electrons produced.
40. The beam intensity is affected by all factors EXCEPT one. Which one is the EXCEPTION? a.
Collimation. b. Exposure time. c. Tube current (mA). d. Tube voltage (kVp).
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41. Which statement BEST describes the half-value layer (HVL)? a. Inherent filtration used to decrease
beam intensity by one half. b. Increased beam intensity to compensate for one half reduction due to
distance. c. Thickness of absorber necessary to reduce the number of x-ray photons by one half. d. Total
filtration necessary to compensate for increased number of electrons produced.
42. Which is the purpose of dental x-ray machine filtration? a. Decrease beam intensity. b. Reduce the
size of the x-ray beam. c. Regulate the shape of the x-ray beam. d. Eliminate low-energy photons.
43. According to government regulations, the total filtration for a dental x-ray machine set at 69 kVp
should be a. 1.0 mm. b. 1.5 mm. c. 2.0 mm. d. 2.5 mm.
44. Which is the purpose of collimation of the x-ray beam? a. Direct photons. b. Intensify beam. c.
Reduce exposure area. d. Adjust for source-to-point distance.
45. If the source-to-point distance is increased, then which adjustment should be made to ensure
consistent image density? a. Increase kVp. b. Decrease mA. c. Increase exposure time. d. Decrease
added filtration.
46. If a dose of 2 Gy is measured at a distance of 4 m, then which is the dose found at 2 m? a. 0.25 Gy.
b. 0.50 Gy. c. 4 Gy. d. 8 Gy.
47. During patient exposure, absorption interactions of photons will do all EXCEPT one. Which one is
the EXCEPTION? a. Cease to exist. b. Ionize absorber atoms. c. Produce a homogenous beam. d.
Convert energy into ejected electron energy.
48. During patient exposure, which type of beam attenuation occurs MOST frequently? a. Coherent
scattering. b. Compton scattering. c. Photoelectric absorption. d. Bremsstrahlung radiation.
49. A photoelectric interaction is MOST LIKELY to occur when photons interact with which tissue? a.
Bone. b. Dentin. c. Soft tissue. d. Tooth pulp.
50. The probability of a Compton interaction is directly proportional to which entity? a. Source-to-point
distance. b. Electron density of the absorber. c. Third power of the atomic number of the absorber. d.
Interaction of a low-energy incident photon with an outer electron.
51. The absorption of the x-ray beam depends upon all factors EXCEPT one. Which one is the
EXCEPTION? a. Energy of beam. b. Density of absorber. c. Thickness of absorber. d. Half-value layer
of beam.
52. Determining the quantity of radiation exposure is called a. filtration. b. dosimetry. c. ionization. d.
K-edge absorption.
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53. A measure of the capacity of radiation to ionize air is called a. exposure. b. absorbed dose. c.
equivalent dose. d. radioactivity level.
54. Which unit is used to compare the high linear energy transfer (LET) of particulate radiations to a
lower-LET radiation such as x-rays? a. Exposure dose. b. Absorbed dose. c. Equivalent dose.
d. Effective dose.
55. Which unit is used to compare the risk of radiation exposure of one part of the body to another part?
a. Exposure dose. b. Absorbed dose. c. Equivalent dose. d. Effective dose.
56. The traditional unit called radiation absorbed dose (rad) is expressed in the SI system as a. gray
(Gy). b. sievert (Sv). c. becquerel (Bq).d. coulomb/kilogram (C/kg).
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Oral Radiology
Version 1
o If the photon was absorbed by the tissue then the beam becomes (attenuated/
homogeneous/heterogeneous).
o Also the electron cloud is caused by…
o There was another question that was like the full wave rectified machine and the self rectified
machine have the
▪
same 2- equal 3- less 4- more energy
o
o
o
o
o
o
o
Which of the following is electromagnetic radiation (xray)
Infrared radiation is a ( non ionizing radiation)
The filter measurment should be (1.5 mm of aluminum)
Compton radiation is absorbed by the patient ? ( true )
Coherent scatteing radiation cause image degradation ?
The target should have a high atomic number to produce effective x ray photons
Which of the following is th smallest, fastest and something from the following ?:
Electron,Alpha particle, Beta particle,
o Which of the following densely ionize electons ? ( Alpha particles)
o The energy that should exceed the electrostatic force called binding energe? ( true or false )
o There were two questions about the self rectified and another one about the photoelectric
absorption
+ Version 2
1. Particulate and electromagnetic radiation are two types of radiation. Answer: True
2. Quantum number can indicate the number of shells an atom has
3. Which one has the most energy? Alpha, beta, cathode, or microwave
4. When the electron hits the target liner energy is changed into? Answer: X-ray photon
5. What's the material of the focal spot? Answer, tungsten
6. A filament should have lower heat conductivity? True or false
7. Something about having low melting point is good? Answer false
8. In the self rectified wave what's happening in the inverse bit
9. A question on the half wave rectified
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10. A t/fqon Characteristic X-rays. No matter which shell is involved the binding energy is always low
and doesn't effect the x-ray?
11. What's the material of the collimating barrier? Answer metal
12. What's used to change the shape and size of the x-Ray beam? Answer collimator
13. Coherent scattering leads to many absorbed photons and damage? False
14. More photoelectric absorption leads to what? Foggy image, no absorbed radiation, full absorbed
15. Another q in photoelectric absorption
16. A q with a KVp number and you have to say the aluminium required, the KVP was 90. Answer:
2.5mm (this question is from chapter 21)
17.1 forgot the question (not from the notes too) but the options were- homogeneous, heterogenous,
neutral
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