Midterm Review Flashcards
1
Q
Energy is measured in _____.
a. kilograms
b. joules
c. electron volts
d. B or C
A
Joules
2
Q
Atoms and molecules are the fundamental building blocks of _____.
a. energy
b. radiation
c. matter
d. gravity
A
Matter
3
Q
The formula E=mc^2 is the basis for the theory that led to the development of _____.
a. x-rays
b. electromagnetic radiation
c. nuclear power
d. cathode ray tubes
A
Nuclear power
4
Q
Radio waves, light, and x-rays are all examples of _____ energy.
a. nuclear
b. thermal
c. electrical
d. electromagnetic
A
Electromagnetic
5
Q
What is the removal of an electron from an atom called?
a. ionization
b. pair production
c. irradiation
d. electricity
A
Ionization
6
Q
The energy of x-rays is _____.
a. thermal
b. potential
c. kinetic
d. electromagnetic
A
Electromagnetic
7
Q
The biggest source of man-made ionizing radiation exposure to the public is _____.
a. atomic fallout
b. diagnostic x-rays
c. smoke detectors
d. nuclear power plants
A
Diagnostic x-rays
8
Q
The basic quantities measured in mechanics are _____, _____, and _____.
a. volume, length, meters
b. mass, length, time
c. radioactivity, dose, exposure
d. meters, kilos, seconds
A
Mass, length and time
9
Q
_____ is a special quantity of radiologic science.
a. Mass
b. Velocity
c. Radioactivity
d. Momentum
A
Radioactivity
10
Q
Exposure is measured in units of _____.
a. becquerel
b. sieverts
c. meters
d. grays
A
Grays
11
Q
Today, radiology is considered to be a(n) _____ occupation.
a. safe
b. unsafe
c. dangerous
d. high-risk
A
Safe
12
Q
What does ALARA mean?
a. All Level Alert Radiation Accident
b. As Low As Reasonably Achievable
c. Always Leave A Restricted Area
d. As Low As Regulations Allow
A
As Low As Reasonably Achievable
13
Q
The smallest particle that has all the properties of an element is a(n) _____.
a. neutron
b. proton
c. electron
d. atom
A
Atom
14
Q
A positively charged nucleus surrounded by negatively charged electrons in well-defined orbits is the _____ model of the atom.
a. Bohr
b. Thomson
c. Rutherford
d. Dalton
A
Bohr
15
Q
What are the fundamental particles of an atom?
a. quark, positron, negatron
b. nucleon, electron, proton
c. proton, neutron, quark
d. proton, electron, neutron
A
Proton, neutron, electron
16
Q
An atom in a normal state has an electrical charge of _____.
a. one
b. zero
c. positive
d. negative
A
Zero
17
Q
The binding energies, or energy levels, of electrons are represented by their _____.
a. atomic numbers
b. atomic mass units
c. shells
d. isotopes
A
Shells
18
Q
When an atom has the same number of protons as another, but a different number of neutrons, it is called an _____.
a. isomer
b. isobar
c. isotone
d. isotope
A
Isotope
19
Q
An atom that loses or gains one or more electrons is a(n) _____.
a. ion
b. molecule
c. isotope
d. isomer
A
Ion
20
Q
The maximum number of electrons that can exist in an electron shell is calculated with the formula _____.
a. 2n
b. 2n^2
c. 2/n
d. 2/n^2
A
2n^2
21
Q
The innermost electron shell is symbolized by the letter _____.
a. J
b. K
c. L
d. M
A
K shell
22
Q
The atomic number of an element is symbolized by the letter _____.
a. A
b. X
c. Z
d. n
A
Z
23
Q
Two identical atoms which exist at different energy states are called _____.
a. isotopes
b. isomers
c. isotones
d. isobars
A
Isomers
24
Q
During beta emission, an atom releases _____.
a. electrons
b. positrons
c. protons
d. neutrons
A
Electrons
25
The only difference between x-rays and gamma rays is their _____.
a. energy
b. size
c. origin
d. name
Origin
26
The four properties of photons are _____, _____, _____ and _____.
a. size, shape, spin, mass
b. frequency, mass, amplitude, wavelength
c. frequency, wavelength, velocity, amplitude
d. refraction, velocity, spin, amplitude
Frequency, wavelength, velocity, amplitude
27
The smallest quantity of any type of electromagnetic radiation is a(n) _____.
a. photon
b. electron
c. neutrino
d. quark
Photon
28
What is the velocity of all electromagnetic radiation?
a. 8 × 10^3 m/s
b. 2 × 10^8 m/s
c. 3 × 10^8 m/s
d. 4 × 10^3 m/s
3 x 10^8 m/s
29
The rate of rise and fall of a sine wave is called its _____.
a. amplitude
b. frequency
c. wavelength
d. velocity
Frequency
30
If the wavelength of a beam of electromagnetic radiation increases by a factor of 2, then its frequency must _____.
a. double
b. increase four times
c. decrease by half
d. remain constant
Decrease by half
31
The intensity of radiation _____ in _____ proportion to the square of the distance of the object from the source.
a. increases, direct
b. decreases, direct
c. increases, inverse
d. decreases, inverse
Decreases, inverse
32
If the intensity of light from a flashlight is 4 millilumens (mlm) at a distance of 3 feet, what will the intensity be at 6 feet?
a. 0.4 millilumens
b. 1 millilumen
c. 2 millilumens
d. 16 millilumens
1 millilumen
33
The energy of a photon is directly proportional to its _____.
a. amplitude
b. frequency
c. velocity
d. wavelength
Frequency
34
X-rays are usually identified by their _____.
a. energy
b. velocity
c. wavelength
d. hertz
Energy
35
Photons with the highest frequencies have the _____.
a. highest velocity
b. lowest energy
c. longest wavelengths
d. shortest wavelengths
Shortest wavelengths
36
The smallest unit of electrical charge is the _____.
a. electron
b. proton
c. neutron
d. neutrino
Electron
37
Electrification occurs through the movement of _____.
a. protons only
b. protons and electrons
c. electrons only
d. electrons and neutrons
Electrons only
38
Like charges _____ and unlike charges _____.
a. repel, repel
b. attract, attract
c. attract, repel
d. repel, attract
Repel, attract
39
```
Electrostatic force is _____ proportional to the distance between charges, and _____ proportional to
the product of the charges.
a. directly, inversely
b. inversely, directly
c. inversely, inversely
d. directly, directly
```
Inversely, directly
40
The charges on an electrified object are distributed _____.
a. in the center of the object
b. on the side nearest the charge
c. on the topside of the object
d. evenly throughout the object
Evenly throughout the object
41
On the surface of an electrified object, the charges concentrate on the _____.
a. top side
b. underside
c. sharpest curvatures
d. smoothest curvatures
Sharpest curvatures
42
A _____ is a source of direct current.
a. wall socket
b. battery
c. generator
d. spark
Battery
43
What is the unit of electric potential?
a. watt
b. amp
c. volt
d. ohm
Volt
44
An electric potential applied to a conductor produces _____.
a. an electric current
b. a magnetic field
c. an electric insulator
d. both A and B
Both an electric current and magnetic field
45
An alternating (AC) current is represented by a _____ line.
a. sinusoidal
b. horizontal
c. vertical
d. descending
Sinusoidal
46
. A _____ uses direct current.
a. hair dryer
b. toaster
c. microwave
d. flashlight
Flashlight
47
Alternating current is produced by a _____.
a. battery
b. generator
c. capacitor
d. semiconductor
Generator
48
What is Ohm’s law?
a. I = V/R
b. V = I/R
c. R = VI
d. I = VR
I = V/R
49
A charged particle in motion creates a(n) _____.
a. negative charge
b. positive charge
c. magnetic field
d. electrostatic charge
Magnetic field
50
Electrical power is measured in _____.
a. coulombs
b. amperes
c. volts
d. watts
Watts
51
Rubber and glass are _____.
a. semiconductors
b. conductors
c. insulators
d. superconductors
Insulators
52
The rotation of electrons on their axis is the property called _____.
a. magnetic force
b. electron spin
c. unified field theory
d. magnetic induction
Electron spin
53
When a group of dipoles are aligned, they create _____.
a. a magnetic domain
b. paramagnetic material
c. magnetic resonance
d. a north pole
Magnetic domain
54
In the United States, alternating current goes through a complete cycle every _____ second.
a. 1/120
b. 1/100
c. 1/60
d. 1/30
1/60 second
55
What is the SI unit of magnetic field strength?
a. ampere
b. tesla
c. dipole
d. ohm
Tesla
56
. The force between magnetic poles is proportional to the _____ of the magnetic pole strengths,
divided by the _____ of the distance between them.
a. square, sum
b. sum, square
c. square, product
d. product, square
Product, square
57
What type of material can be made magnetic when placed in an external magnetic field?
a. diamagnetic
b. ferromagnetic
c. paramagnetic
d. nonmagnetic
Ferromagnetic
58
Like magnetic poles _____ and unlike magnetic poles _____.
a. attract, attract
b. repel, repel
c. repel, attract
d. attract, repel
Repel, attract
59
Water is a _____ material.
a. paramagnetic
b. magnetic
c. diamagnetic
d. ferromagnetic
Diamagnetic
60
The magnetic intensity of an electromagnet is greatly increased by the addition of a(n) _____ core.
a. wood
b. iron
c. aluminum
d. copper
Iron core
61
The transformer changes:
a. on AC but not on DC
b. on both DC and AC
c. on DC but not on AC
d. only above its critical current
e. only on a constant voltage
On AC but not on DC
62
The output current in a step-up transformer is:
a. higher than the input current
b. independent of the input current
c. independent of the turns ratio
d. lower than the input current
e. the same as the input current
Lower than the input current
63
If DC is applied to the primary coil of a step-up transformer, what is the result in the secondary coil?
a. AC
b. Increased current
c. Increased magnetic field
d. Increased voltage
e. Nothing
Nothing
64
Power to the primary side of the high-voltage transformer comes from the:
a. Filament transformer
b. Line-voltage compensator
c. Primary side of the autotransformer
d. Rectifier
e. Secondary side of the autotransformer
Secondary side of the transformer
65
The autotransformer has only one:
a. Coil
b. Meter
c. Rectifier
d. Switch
e. Turns ratio
Coil
66
Line compensation:
a. Adjusts the line frequency to 60 Hz
b. Compensates for rectification
c. Is necessary for proper exposure timing
d. Is necessary to convert AC to DC
e. Is required to stabilize voltage
Is required to stabilize voltage
67
The filament transformer:
a. Has four windings
b. Increases current
c. Increases voltage
d. Is an autotransformer
e. Must have precision resistors
Increases current
68
The design of fixed mA stations requires the use of which of the following?
a. A center-tapped meter
b. DC power
c. Major and minor taps
d. Precision resistors
e. Primary and secondary windings
Precision resistors
69
A change in the voltage waveform from the primary side to the secondary side of the high-voltage transformer produces a change in:
a. Amplitude
b. Frequency
c. Phase
d. Velocity
e. Wavelength
Amplitude
70
Which of the following is an advantage of three-phase power over single-phase power?
a. Improved spatial resolution
b. Increased kVp
c. Increased mAs
d. Increased x-ray intensity per mAs
e. Lower capital cost
Increased x-ray intensity per mAs
71
Oil is used in the high-voltage section of an x-ray imaging system for which of the following functions?
a. Electrical insulation
b. Reduction of rotor friction
c. Reduction of voltage ripple
d. Thermal conduction
e. Voltage rectification
Electrical insulation
72
If 60 Hz AC power is full-wave rectified, output voltage consists of:
a. 60 pulses per second
b. 90 pulses per second
c. 120 pulses per second
d. 70% ripple
e. Zero ripple
120 pulses per second
73
True/False
As the kinetic energy of the incident electron increases, so does the efficiency of the photon production.
TRUE
74
True/False
In the diagnostic range, the kinetic energy of the incident electrons is high enough to eject an outer-shell electron causing ionization.
TRUE
75
True/False
In a bremsstrahlung interaction, the closer the incident electron travels to the nucleus, the lower the energy of the resultant x-ray photon.
FALSE
76
True/False
The electron ejected during a characteristic interaction is also known as the x-ray photon.
FALSE
77
True/False
The creation of a characteristic photon is always the result of a K-shell electron ejection.
FALSE
78
True/False
The creation of a characteristic photon in the diagnostic range is always the result of a K-shell electron ejection.
FALSE
79
True/False
As the tube ages, the anode begins to pit and the glass envelope may gain a mild coating of vaporized metal. This will cause a decrease in inherent filtration.
FALSE
80
True/False
Inherent filtration is the filtration found within the tube design.
TRUE
81
True/False
In diagnostic radiology, filtration is typically added between the source and the patient.
TRUE
82
Almost all of the kinetic energy of the incident electrons is converted to
a. a bremsstrahlung photon c. light
b. a characteristic x-ray photon d. heat
Heat
83
What percentage of target interaction results in the production of x-ray photons?
a. 1 percent c. 99 percent
b. 50 percent d. 100 percent
1 percent
84
The transfer of the incident electrons’ kinetic energy to the outer-shell electrons causing vibration of the outer-shell electron results in the emission of
a. infrared radiation. c. light.
b. ultraviolet radiation. d. sound.
Infared radiation
85
The types of target interaction that occur in the production of diagnostic-range x-ray photons are dependent upon
a. electron kinetic energy.
b. nuclear binding energy.
c. electron potential energy.
d. both a and b
Electron kinetic energy
86
The energy of a bremsstrahlung photon is
a. equal to the kinetic energy of the entering electron.
b. equal to the kinetic energy of the exiting electron.
c. the sum of the entering and exiting kinetic energy of the electron.
d. the difference between the entering and exiting kinetic energy of the electron.
The difference between the entering and exiting kinetic energy of the electron
87
Bremsstrahlung interactions may occur only when the incident electron interacts with
a. an inner-shell electron.
b. an outer-shell electron.
c. the force field of the nucleus.
d. none of the above
The force field of the nucleus
88
Characteristic interactions may occur only when the incident electron interacts with
a. an inner-shell electron.
b. an outer-shell electron.
c. the force field of the nucleus.
d. none of the above
An inner shell electron
89
During a characteristic interaction, the energy of the incident electron must be ____ the electron it knocks from its orbit.
a. less than that of
b. greater than that of
c. proportional to that of
d. characteristic of
Greater than that of
90
During a characteristic interaction, the dropping of a higher-energy state electron into a lower-energy state “hole” results in the emission of
a. a photon of energy.
b. a high-energy electron.
c. a low-energy electron.
d. more than one of the above
A photon of energy
91
The energy of a characteristic photon is
a. equal to the binding energy of the entering electron.
b. equal to the binding energy of the exiting electron.
c. the sum of the binding energy of the outer and inner shells between which the electron dropped.
d. the difference between the binding energy of the outer and inner shells between which the electron dropped.
The difference between the binding energy of the outer and inner shells between which the electron dropped.
92
At the end of the characteristic cascade, the ____ shell is missing an electron.
a. innermost
b. K
c. outermost
d. characteristic
Outermost
93
The K-shell can hold a maximum of ____ electrons.
a. 1
b. 2
c. 6
d. 8
2 electrons
94
Filtration is the process of eliminating undesirable ____ by the insertion of absorbing materials into the primary beam.
a. high-energy x-ray photons
b. high-energy incident electrons
c. low-energy x-ray photons
d. low-energy incident electrons
Low energy x-ray photons
95
Filtration permits the radiographer to ____ the photon emission spectrum into a more useful beam.
a. narrow
b. widen
c. soften
d. There is no effect.
Narrow
96
Filtration has what effect on patient dose?
a. It has no effect on patient dose.
b. It increases patient dose.
c. It decreases patient dose.
d. It increases occupational worker dose.
It decreases patient dose
97
Which of the following materials is/are used as a filter?
a. glass
b. oil
c. aluminum
d. all of the above
All of the above
98
All filtration can be expressed in terms of the thickness of
a. HVL.
b. Pb/Eq.
c. Al/Eq.
d. Sn/Eq..
Al/Eq
99
The amount of material that will reduce the intensity of the primary beam to one-half its original value is the
a. half-value layer.
b. radioactive half-life.
c. aluminum equivalency
d. half-life equivalency.
Half value layer
100
Which of the following is affected by half-layer value?
a. anode construction
b. image quality
c. target longevity
d. patient exposure
Patient exposure
101
How many half-value layers must be added to the primary beam to reduce its intensity to less than 20 percent of its original value?
a. 1
b. 2
c. 3
d. 4
3
102
Which one of these statements is true?
a. The thickest portion of the wedge filter is placed over the densest part of the patient.
b. The thickest portion of the wedge filter is placed over the less dense part of the patient.
c. The thinnest portion of the wedge filter is placed over the less dense part of the patient.
d. A wedge filter should not be used to compensate for unequal subject density.
The thickest portion of the wedge filter is placed over the less dense part of the patient.
103
The reduction in the number and energy of photons as radiation passes through matter is termed:
a. Irradiation
b. Deflection
c. Photoelectrolysis
d. Attenuation
Attenuation
104
The production of scatter radiation wen x-radiation strikes an object principally results from:
a. Compton interaction
b. Brem’s event
c. Characteristic event
d. Photoelectric interaction
Compton interaction
105
The type of interaction in the diagnostic range responsible for the radiographic contrast between soft tissue and bone is:
a. Compton interaction
b. Coherent scattering
c. Pairs production
d. Photoelectric absorption
Photoelectric absorption
106
At photon energies above 1.02 MeV, the creation of a negatron and a positron may occur in an event termed:
a. Photodisintegration
b. Pairs production
c. Annihilation reaction
d. Van de Graff production
Pairs production
107
The photoelectric interaction most commonly occurs when the incident photon strikes a/an:
a. Inner shell electron
b. Outer shell electron
c. Protons
d. Neutron
Inner shell electron
108
The interaction of a x-ray photon and an orbital electron, which results in partial transfer of energy is
a. Photoelectric effect
b. Pairs production
c. Compton scatter
d. Thomas scatter
Compton scatter
109
At 70 KeV photon strikes and inner shell electron, all of the photon energy is transferred to the electron. This describes:
a. Coherent scattering
b. Compton scattering
c. Photoelectric effect
d. Photodisintegration
Photoelectric effect
110
The incoming photon before any interaction with matter takes place is called the :
a. Incident photon
b. Scatter photon
c. Inherent photon
d. Recoil photon
Incident photon
111
Which of the following interactions contributes to image noise?
a. Brems
b. Characteristic
c. Compton
d. Photodisintegration
e. Photoelectric effect
Compton
112
Compton scatter is:
a. Independent of Z#
b. Inversely proportional to Z#
c. Proportional to E
d. Proportional to Z#2
Independent of Z#
113
The probability that a photon will undergo attenuation :
a. Decreases with increasing energy
b. Increases with decreasing electron energy
c. Increases with increasing electron energy
d. Increase with increasing x-ray energy
Decreases with increasing energy
114
The photoelectric effect is principally associated with which of the following?
a. Absorption of an x-ray
b. Brems production
c. Characteristic production
d. Scattering of an x-ray
Absorption of an x-ray
115
During photoelectric interactions:
a. An electron is emitted from an atom
b. An x-ray is emitted from the atom
c. Electron excitation results
d. The atom is made radioactive
An electron is emitted from an atom
116
A 35 KeV x-ray will most likely undergo a k-shell PE interaction with which of the following?
a. Barium, BE of 37 keV
b. Calcium, BE of 4 keV
c. Iodine, BE of 33 keV
d. Tungsten, BE of 69 keV
Iodine, BE of 33 keV
117
The probability of the PE effect varies as what function of x-ray energy?
a. E^-3
b. E^-2
c. E
d. E^2
e. E^3
E^-3
118
A 39 keV photon interacts through PE absorption with a k-shell electron having a BE of 37 keV. Therefore:
a. The photoelectron will have 2 keV of energy
b. The photoelectron will have 37 keV of energy
c. The photoelectron will have 39 keV of energy
d. The scatter x-ray will have 2 keV of energy
The photoelectron will have 2 keV of energy
119
Differential absorption between bone and soft tissue occurs principally for which of the following reasons?
a. The difference in Z#
b. The difference in mass density
c. The polychromatic x-ray beam
d. The monochromatic x-ray beam
The difference in Z#
120
The passage of x-ray photons through a patient without interaction is called:
a. Absorption
b. Attenuation
c. Scattering
d. Direct transmission
Direct transmission
121
In which of the following x-ray interactions with matter is the energy of the incident photon completely absorbed?
a. Compton
b. Photoelectric
c. Incoherent
d. Rayleigh
Photoelectric
122
Compton scattered electron:
a. Annihilated another electron
b. Is absorbed within a few microns of the site of the original Compton interaction
c. Causes pair production
d. Engages in the process of photodisintegration
Is absorbed within a few microns of the site of the original Compton interaction
123
Within the energy range of diagnostic radiology that includes mammography, when kVp is decreased, the patient dose:
a. Decreases
b. Increases
c. Remains the same
d. Doubles
Decreases
124
The quality, or penetrating power, of an x-ray beam is controlled by:
a. The absorption characteristics of the patient being radiographed
b. Flourescent yield
c. mAs
d. kVp
kVp
125
kVp controls:
a. Absorption characteristics of the body part being radiographed
b. Fluorescent yield
c. Random interaction of x-ray photons with the image receptor
d. Quality, or penetrating power, of the photons in the x-ray beam
Quality, or penetrating power, of the photons in the x-ray beam
126
The process most responsible for the contrast between bone and soft tissue in a diagnostic radiographic image is:
a. Coherent scattering
b. Compton scattering
c. Photoelectric absorption
d. Photodisintegration
Photoelectric absorption
127
True/False
In the radiographic kilovoltage range, compact bone with a high calcium content by weight undergoes much more photoelectric absorption than an equal mass of soft tissue and air
TRUE
128
What is photoelectric effect?
The incident x-rays interacts with an inner-shell electron and ejects it from the atom, ionizing the atom.
129
What are characteristic x-rays in the photoelectric effect?
Characteristic x-rays are then produced as outer-shell electrons fill the void left by the inner shell electron
