MIDTERM Qs (ALL TESTED QUESTIONS) Flashcards
1
Q
TRUE/FALSE
Technologists wear a TLD type personnel monitoring device.
A
FALSE
2
Q
TRUE/FALSE
The common property of all electromagnetic (EM) radiation is frequency.
A
FALSE
3
Q
The wavelength of an electromagnetic wave is:
inversely proportional to wave velocity
directly proportional to wave frequency
inversely proportional to wave frequency
usually designated by the letter c
A
inversely proportional to wave frequency
4
Q
TRUE/FALSE
Time, Distance and shielding are the cardinal rules of radiation safety.
A
TRUE
5
Q
Which of the following creates the most ionizations in air, and has a radiation weighting factor of 4?
x-ray
beta particle
alpha particle
they are equal
A
alpha particle
6
Q
If the photon (x-ray) frequency is increased tenfold, then the:
velocity will increase times 10
velocity will decrease to 10
wavelength will increase times 10
wavelength will decrease to 1/10
A
wavelength will decrease to 1/10
7
Q
A technologist is exposed to 10 mR of radiation at a distance of 50 cm . What distance would result in an exposure of 100mR?
5 cm
500 cm
16 cm
160 cm
A
16 cm
8
Q
Background radiation accounts for 6 mSv of exposure, man mad sources account for ____mSv of that.
1
2
3
4
A
3
9
Q
In the ionization process an electron is removed from an atom. In excitation the electron is moved to a/an ___ energy state.
lower
higher
incomplete
all of the above
A
higher
10
Q
TRUE/FALSE
Air KERMA is an easily measured and comparable factor used for entrance skin exposure.
A
TRUE
11
Q
Which of the following units of measure are used for patient absorbed dose?
R
Sv
Gy
Bq
A
Gy
12
Q
The particles that distinguish one element from another are the
neutrons
protons
electrons
beta particles
A
protons
13
Q
TRUE/FALSE
Thomas Edison discovered x-rays.
A
FALSE
14
Q
A gamma ray is created in ___ and an x-ray is created in ___.
nucleus of an atom, x-ray tube
x-ray tube, nucleus of an atom
nucleus of an atom, image tube
none of the above
A
nucleus of an atom, x-ray tube
15
Q
Visible light (moderate energy) acts like a ___ while x-rays(high energy) act like a ___.
particle, particle
wave, particle
particle, wave
wave, wave
A
wave, particle
16
Q
If an electron is gained or lost from an atom, that atom becomes:
an ion
a new element
an isotope
unstable
A
an ion
17
Q
TRUE/FALSE
0.05 Sv or 5 rem is the yearly occupational dose limi in the US.
A
TRUE
18
Q
What unit of measure is used for the absorbed dose multiplied by the radiation weighting factor in the SI system
rem
Gy
Ci
Sv
A
Sv
19
Q
The theory that electrons circulate in discrete circular paths was proposed by
Bohr
Einstein
Planck
Rutherford
A
Bohr
20
Q
The maximum number of electrons found in any energy level (shell) at any point in time is
2
6
10
2n^2
A
2n^2
21
Q
TRUE/FALSE
Stochastic effects of radiation require a threshold dose before they are detectable.
A
FALSE
22
Q
WhIch of the following describes a product of the absorbed dose, the radiation weighting factor and the tissue sensitivity?
Effective dose
Equivalent dose
Absorbed dose
Tissue KERMA
A
Effective dose
23
Q
The sum of protons and neutrons in a nucleus is called the
electron number
atomic weight
quantum number
atomic mass
A
atomic mass
24
Q
Isotopes have ______ number of protons and ________ number of neutrons compared to a stable atom of a material.
the same, the same
the same, different
different, the same
different, different
A
the same, different
25
Frequency and the energy of electromagnetic waves have a ___ relationship, as explained by Plank's equation. .
directly proportional
inversely proportional
exponential
indirect linear
directly proportional
26
Matter is measured in ____.
kilograms
joules
electron volts
rems
kilograms
27
Energy is measured in ____.
kilograms
curies
electron volts
becqurels
electron volts
28
Atoms and molecules are the fundamental building blocks of ____.
energy
radiation
matter
gravity
matter
29
Radio waves, light, and x-rays are all examples of ____ energy.
nuclear
thermal
electrical
electromagnetic
electromagnetic
30
What is the removal of an electron from an atom called?
ionization
pair production
irradiation
electricity
ionization
31
The energy of x-rays is ____.
thermal
potential
kinetic
electromagnetic
electromagnetic
32
The biggest source of man-made ionizing radiation exposure to the public is ____.
atomic fallout
diagnostic x-rays
smoke detectors
nuclear power plants
diagnostic x-rays
33
___ is a special quantity of radiologic sciences.
mass
velocity
radioactivity
momentum
radioactivity
34
Absorbed dose is measured in units of ____.
becquerel
sieverts
meters
grays
grays
35
Today, radiology is considered to be a(n) ___ occupation.
safe
unsafe
dangerous
high-risk
safe
36
What does ALARA mean?
All Level Alert Radiation Accident
As Low As Reasonably Achievable
Always Leave A Restricted Area
As Low As Regulations Allow
As Low As Reasonably Achievable
37
The smallest particle that has all the properties of an element is a(n) ____.
neutron
proton
electron
atom
atom
38
A positively charged nucleus surrounded by negatively charged electrons in well-defined orbits is the ___ model of the atom.
Bohr
Thomson
Rutherford
Dalton
Bohr
39
The chemical element is determined by the number of ___ in the atom.
protons
electrons
neutrons
nucleons
protons
40
An atom in a normal state has an electrical charge of ___.
one
zero
positive
negative
zero
41
The binding energies, or energy levels, of electrons are represented by their ____.
atomic numbers
atomic mass units
shells
isotopes
shells
42
When an atom has the same number of protons as another, but a different number of neutrons, it is called an ____.
isomer
isobar
isotone
isotope
isotope
43
TRUE/FALSE
KERMA is a measure only done in air.
FALSE
44
An atom that loses or gains one or more electrons is a(n) ____.
ion
molecule
isotope
isomer
ion
45
The maximum number of electrons that can exit in the 2nd electron shell is calculated with ____.
2*2
2*2^2
2/2
2/2^2
2*2^2
46
The absorbed dose for the PA view of the chest is 1 mrad, the absorbed dose for the lateral view of the chest is 4 mrad. What is the integral dose for this chest exam?
1
3
4
5
5
47
The atomic number of an element is symbolized by the letter ____.
A
X
Z
n
Z
48
Deterministic effects of radiation include all of the following except______?
skin burns
hairloss
sterility
cancers
cancers
49
During beta emission, an atom releases ____.
electrons
positrons
protons
neutrons
electrons
50
The only difference between x-rays and gamma rays is their ____.
energy
size
origin
name
origin
51
The ___ is the least penetrating form of ionizing radiation.
beta particle
x-ray
gamma ray
alpha particle
alpha particle
52
The three properties of photons are ___, ____, and ____.
size, shape, spin
frequency, mass, amplitude
frequency, wavelength, energy
refraction, velocity,amplitude
frequency, wavelength, energy
53
The theory of ALARA for health care workers supports which of the following practices for pregnant technologist?
No rotations through fluoroscopy
Limited rotations through portable examinations
No interventional or OR rotations
no modification to the work rotation
no modification to the work rotation
54
What is the velocity of all electromagnetic radiation?
8 x 10^3 m/s
2 x 10^8 m/s
3 x 10^8 m/s
4 x 10^3 m/s
3 x 10^8 m/s
55
The rate of rise and fall of a sine wave is called its ____.
amplitude
frequency
wavelength
velocity
frequency
56
A hertz (Hz) is equal to ___ cycle(s) per second.
103
102
10
1
1
57
If the wavelength of a beam of electromagnetic radiation increases by a factor of 2, then its frequency must ____.
double
increase four times
decrease by half
remain constant
decrease by half
58
The intensity of radiation ___ in ___ proportion to the square of the distance of the object from the source.
increases, direct
decreases, direct
increases, inverse
decreases, inverse
decreases, inverse
59
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?
0.4 millilumens
1 millilumen
2 millilumens
16 millilumens
1 millilumen
60
The energy of a photon is directly proportional to its ____.
amplitude
frequency
velocity
wavelength
frequency
61
Photons with the highest frequencies have the ____.
highest velocity
lowest energy
longest wavelengths
shortest wavelengths
shortest wavelengths
62
The smallest unit of electrical charge is the ____.
electron
proton
neutron
neutrino
electron
63
Electrification occurs through the movement of ____.
protons only
protons and electrons
electrons only
electrons and neutrons
electrons only
64
Like charges ____ and unlike charges ____.
repel, repel
attract, attract
attract, repel
repel, attract
repel, attract
65
The charges on an electrified object are distributed ____.
in the center of the object
on the side nearest the charge
evenly on the surface of the object
on the side opposite the charge
evenly on the surface of the object
66
On the surface of an electrified object, the charges concentrate on the ____.
top side
underside
sharpest curvatures
smoothest curvatures
sharpest curvatures
67
A ___ is a source of direct current.
wall socket
battery
generator
spark
battery
68
What is the unit of electric potential?
watt
amp
volt
ohm
volt
69
An electric potential applied to a conductor produces ____.
an electric current
a magnetic field
an electric insulator
both A and B
both A and B
70
An alternating (AC) current is represented by a ____ line.
sinusoidal
horizontal
vertical
descending
sinusoidal
71
What is Ohm's law?
I = V/R
V = I/R
R = VI
I = VR
I = V/R
72
A charged particle in motion creates a(n) ____.
negative charge
positive charge
magnetic field
electrostatic charge
magnetic field
73
Electrical power is measured in ____.
coulombs
amperes
volts
watts
watts
74
Rubber and glass are ___.
semiconductors
conductors
insulators
superconductors
insulators
75
When a group of atomic dipoles are aligned, they create ____.
a magnetic domain (a magnet)
paramagnetic material
magnetic induction
magnetic repulsion
a magnetic domain (a magnet)
76
What is the SI unit of magnetic field strength?
ampere
tesla
dipole
ohm
tesla
77
Methods of electrification are all of the following except
retention
friction
contact
induction
retention
78
Radiation protection practices, for example, shielding all patients and applying ALARA principles are based on the theory of ________, which has a non threshold relationship.
Deterministic
Stochastic
Erythema
Epilation
Stochastic
79
In diagnostic imaging (x-rays) 4.2 R of exposure is said to be equivalent to _________ absorbed dose.
4. 2 rem
0. 042 Rad
0. 042 Air Kerma
0. 042 Gy
0.042 Gy
80
Which of the following describes the type of radiation used, the tissue exposed and the amount absorbed, in other words, which tells us the most information regarding an exposure to radiation?
Integral dose
Air Kerma
Effective dose
Equivelent dose
Effective dose
81
TRUE/FALSE
AC current is required in the x-ray tube, and DC current is required in the transformers
FALSE
82
The filament in the x-ray tube requires ______ amperes to emit electrons, thermionic emission.
0.5-1
1-2
3-5
not enough information to answer
3-5
83
TRUE/FALSE
The high voltage generator consists of a high voltage transformer, rectifiers and an autotransformer
FALSE
| no autotransformer
84
the most likely found incoming line current in a modern radiography system is
single phase power
three phase power
direct current
~ 60 volts
three phase power
85
The incoming power to a step up transformer is 100 V, 10 A with a turns ration of 250:1.
What is the resulting voltage in this transformer?
25,000 kV
25,000 V
0. 4 kV
0. 4 V
25,000 V
| 100 * 250
86
The voltage in the x-ray circuit is adjusted or fine tuned in the __________ for ease and safety.
filament transformer
high voltage transformer
rectifier circuit
autotransformer
autotransformer
87
An induction motor is used in what area of imaging?
rotor rotation
power increase
x-ray table movement
all of the above
rotor rotation
88
A filament transformer with a turns ration of 1:20 provides 3.1 amperes to the filament. What is the current flowing through the primary coil of the transformer?
62
6. 2
1. 55
.155
.155
| .155 * 20
89
TRUE/FALSE
In single phase power systems, the potential never drops to zero.
FALSE
90
When full wave rectification is applied to three phase current, a varying (slight increases and decreases over time) ____ is produced.
current
star
double
voltage
voltage
91
The electrical device used to adjust the mA station is the
autotransformer
stator
switch
precision resistor
precision resistor
92
Nearly all hard wired equipment operates on incoming line voltage of
440 V
120 AC
120 Hz
210 A
440 V
93
All of the following are radiographer operated controls except
kVp selection
generator selection
rotor switch
mA selection
generator selection
94
A step down transformer has ______ windings in the secondary vs. primary side.
less
more
the same
none of the above
less
95
TRUE/FALSE
The basic x-ray circuit is divided into the main circuit and the anode circuit.
FALSE
96
A single phase full wave rectified system produces _____ pulses per cycle.
1
2
6
12
2
97
TRUE/FALSE
The mAs in a system controls the quality of the beam.
FALSE
98
At what point in the x-ray circuit is the rectification circuit located?
between the semiconductors and the valve tubes
between the step down transformer and the rheostat
between the step up transformer and the x-ray tube
between the thermionic diode tubes and the x-ray tube
between the step up transformer and the x-ray tube
99
Which of the following transformers has one winding?
Filament transformer
Hi voltage transformer
Autotransformer
none of the above
Autotransformer
100
Which of the following waveforms has the highest efficiency?
Three phase 6 pulse
three phase 12 pulse
single phase full wave
all are equal
three phase 12 pulse
101
An increase in kVp would ___ the ___ of the emission spectrum.
increase, position alone
increase, amplitude alone
increase, amplitude and position (shift to right)
not effect, amplitude and position
increase, amplitude and position (shift to right)
102
Voltage across the x-ray tube is most constant with ____.
high frequency generators
single-phase, half-wave rectification
single-phase, full-wave rectification
three-phase, full-wave rectification
high frequency generators
103
The quantity of bremsstrahlung radiation increases proportionately with increased ___.
kVp
mAs
filtration
rotor speed
mAs
104
Variations in power distribution to the x-ray machine are corrected by the ____.
line voltage compensator
high voltage autotransformer
full-wave rectifier
automatic exposure control
line voltage compensator
105
Cracking on the anode can occur from ___.
filament vaporization
a single excessive exposure
long exposure times
high kVp and low mA
a single excessive exposure
106
The efficiency of x-ray production increases as ___ increases.
mA
kVp
time
both A and B
kVp
107
A step-down transformer is located in the ___ circuit.
tube
timing
filament
rectifier
filament
108
The least accurate type of timer is the ____ timer.
mechanical
electronic
synchronous
mAs
mechanical
109
The external structure of the x-ray tube includes the support structure, the protective housing, and the ___.
anode
cathode
glass envelope
focusing cup
glass envelope
110
The x-ray beam generated by the circuit with the ___ voltage ripple has the ___ quantity and quality.
no correlation between V ripple and quality and quantity
highest, highest
lowest, highest
lowest, lowest
lowest, highest
111
Bremsstrahlung x-rays are produced by ___ at the target.
outer shell excitation
slowing electrons
K-shell interactions
L-shell interactions
slowing electrons
112
The ___ is/are outside the glass envelope.
stators
rotor
focal spot
filaments
stators
113
Full-wave rectified, three-phase units provide an x-ray beam at ___ pulse(s) per second.
1
60
120
360
360
114
The heel effect is caused by the ___.
stator windings
anode angle
exposure times
induction motor
anode angle
115
What is the formula for heat units for a 3-phase, 6-pulse x-ray machine?
kVp x mA x seconds
1. 35 x kVp x mA x seconds
1. 41 x kVp x mA x seconds
1. 66 x kVp x mA x seconds
1.35 x kVp x mA x seconds
116
The effective focal spot size is ___ the actual focal spot size.
equal to
larger than
equal to or larger than
smaller than
smaller than
117
Projectile electrons travel from ___.
anode to cathode
cathode to anode
target to patient
inner shell to outer shell
cathode to anode
118
The useful characteristic x-rays from tungsten targets are ___-shell x-rays.
K
L
M
N
K
119
Changes in ___ result in directly proportional changes in the amplitude of the emission spectrum.
mA
time
kVp
both A and B
both A and B
120
The ____ circuit (transformer) provides electrons for the cathode within the x-ray tube.
rectifier
autotransformer
high voltage
filament
filament
121
Extra-focal or off-focus radiation is produced from ___.
overheated anodes
scattered x-rays
non focused electrons
dual focus cathodes
non focused electrons
122
The x-ray intensity is lower on the anode side of the tube because of the ___.
line focus principle
heel effect
focusing cup
filament length
heel effect
123
Most of the x-rays produced at the target are ___.
bremsstrahlung
characteristic
gamma
beta
bremsstrahlung
124
Most of the heat generated at the target is due to ___.
inner-shell ionization
outer-shell excitation
nucleus bombardment
K x-rays
outer-shell excitation
125
The difference in the waveform between the primary and secondary sides of the high voltage transformer is ____.
frequency
velocity
amplitude
all of the above
amplitude
126
High capacity tube rotors revolve at ___ rpm.
2,000
3,600
6,000
10,000
10,000
127
Thermionic emission at the filament determines the ___ across the x-ray tube during an exposure.
kilovoltage
milliamperage
resistance
magnetism
milliamperage
128
The rotating anode is turned by a ___.
thermal cushion
rotating belt
magnetic field
mechanical pulley
magnetic field
129
The filament in an x-ray tube is about ___ cm in length.
1-2
3-4
8-10
10-20
1-2
130
Which of the following component receives power first in the x-ray circuit ?
mA meter
high voltage transformer
rectifier
autotransformer
autotransformer
131
The mAs timer is usually set to give the ___ mA at the ___ time.
highest, highest
highest, shortest
lowest, shortest
lowest, highest
highest, shortest
132
At 55 kVp, ___ of the useful x-rays produced are bremsstrahlung.
15%
80%
100%
none
100%
133
The x-ray generator with the lowest power rating is the ___ imaging system.
high frequency
three-phase, twelve-pulse
three-phase, six-pulse
single-phase
single-phase
134
Electron interactions at the inner-shell of the target atoms produce ___ radiation.
gamma
Bremsstrahlung
characteristic
all of the above kinds of
characteristic
135
Tube failure can occur from ___.
focal radiation
short exposure times
low kVp techniques
long exposure times
long exposure times
136
An exposure taken at 100 kVp would have a continuos emission spectrum with a maximum energy of ___ keV.
30
69
100
140
100
137
With half-wave rectification, the current flows through the x-ray tube during the ___ part of the cycle.
zero
positive or negative
positive
negative
positive
138
A single-phase waveform has ___ ripple.
1%
4%
14%
100%
100%
139
The automatic exposure control (AEC) terminates the exposure when ____.
the set time is reached
set radiation leaves the x-ray tube
sufficient radiation reaches the image receptor
the correct mAs is reached
sufficient radiation reaches the image receptor
140
The filament is made of ____.
graphite
tungsten
copper
molybdenum
tungsten
141
The high voltage generator contains the high voltage transformer, the ___, and the ___.
autotransformer, timer
timer, rectifiers
kVp meter, filament transformer
filament transformer, rectifiers
filament transformer, rectifiers
142
The three main parts of the x-ray imaging system are the x-ray tube, ____, and ____.
protective barrier, tabletop
operating console, high voltage generator
rectification circuit, operating console
crane assembly, tabletop
operating console, high voltage generator
143
Because of the line focus principal, the effective focal spot size decreases with decreasing ___.
target angle
rotor speed
window thickness
space charge
target angle
144
When electrons bombard the target, ___% of their kinetic energy is converted to heat.
10
25
50
99
99
145
As an x-ray tube ages, the inside can become coated with tungsten, which can cause ___ in the tube.
convection
anode pitting
on-focus radiation
arcing
arcing
146
At the target, the projectile electrons characteristically interact with ___ but are not useable radiation.
outer-shell electrons
inner-shell electrons
atomic nuclei
only A and B
outer-shell electrons
147
The following emission spectrum (SAME SHAPE, HIGHER # OF X-RAY PHOTONS) represents and increase in?
kVp
filtration
generator type
mAs
mAs
148
The ___ is the source of radiation in the x-ray tube.
filament
focal spot
focusing cup
stator
focal spot
149
Thermionic emission at the filament creates a ___.
space charge
grid control
line focus
heel effect
space charge
150
A diode allows electrons to flow from ____.
anode to cathode
cathode to anode
cathode to cathode
anode to anode
cathode to anode
151
An increase in mAs would ___ the ___ of the emission spectrum.
increase, position alone
increase, amplitude alone
increase, amplitude and position
not effect, amplitude and position
increase, amplitude alone
152
Which of the following changes are represented in the following emission spectrum (LOWER PHOTON INTENSITY, SLIGHT SHIFT INSIDE AND TO THE RIGHT)?
filtration
kVp
mAs
anode material
filtration
153
Characteristic x-rays are produced by ___.
braking electrons
excitation of outer shell electrons
nuclear fragmentation
released binding energy
released binding energy
154
The ___ of an x-ray beam is higher when the peak of the emission spectrum is further to the ___.
quality, right
quantity, right
quality, left
quantity, left
quality, right
155
The operating console contains circuits that are ____.
both high voltage and low voltage
high voltage only
low voltage only
non-voltage
low voltage only
156
Characteristic K-shell tungsten x-rays have an effective energy of ___ keV.
0.6
3
12
69
69
157
The cathode side of the tube should be directed toward the ___ part of the patient.
upper
lower
thicker
thinner
thicker
158
The negative side of the x-ray tube holds the ____.
filament
anode
target
rotor
filament
159
The production of heat at the anode is directly proportional to ___.
rotor speed
mAs
kVp
voltage ripple
mAs
160
The autotransformer has ____ winding(s).
one
two
three
four
one
161
TRUE/FALSE
A photoelectric interaction is more likely to occur when the x-ray photon energy and the electron binding energy are farther from one another.
FALSE
162
During photoelectric absorption, the ejected electron is called a/an
incident electron
photoelectron
characteristic electron
nuclear electron
photoelectron
163
The photon that exits the atom after a Compton scattering is called the Compton
scattered photon
scattered electron
recoil electron
photoelectron
scattered photon
164
TRUE/FALSE
During pair production, the positively charged electron is termed a negatron.
FALSE
165
When an x-ray photon with a slightly greater energy than the binding energy of the inner-shell electron interacts with that inner-shell electron, the following interaction results:
Compton scattering
coherent scattering
photoelectric absorption
characteristic radiation
photoelectric absorption
166
Which of the following interactions has a significant impact on the x-ray image?
Compton scattering
coherent scatter
pair production
photodisintegration
Compton scattering
167
During coherent scattering, the scattered photon possesses ___ as the incident photon.
the same energy, the same frequency, and the same wavelength
the same energy, the same frequency, and a different wavelength
the same energy, a different frequency, and the same wavelength
a different energy, the same frequency, and the same wavelength
the same energy, the same frequency, and the same wavelength
168
TRUE/FALSE
When a scattered photon is deflected back toward the source, it is traveling in the direction opposite to the incident photon and is called backscatter radiation.
TRUE
169
What is the total differential absorption in bone compared to fat?
bone Z# 13.8 and mass density 1900 kg/m3
fat Z# 6.8 and mass density 910 kg/m3
0. 51
1. 05
4. 02
17. 5
17.5
170
During which interaction with matter is the x-ray photon converted to matter in the form of two electrons?
pair production
Compton scattering
photoelectric absorption
coherent scattering
pair production
171
In which element are the inner-shell electrons more tightly bound to the nucleus?
mercury (Z = 80)
tungsten (Z = 74)
lead (Z = 82)
chromium (Z = 24)
lead (Z = 82)
172
Which of the following interaction has a significant impact on the x-ray image?
photoelectric absorption
coherent scatter
pair production
photodisintegration
photoelectric absorption
173
Which atomic shell possesses the highest binding energy?
K
L
M
all atomic shells possess the same binding energy
K
174
Which of the following interactions with matter results in a radiograph with a short scale of contrast (high contrast black and white image)?
Compton scattering
coherent scatter
photoelectric interactions
photodisintegration
photoelectric interactions
175
When x-ray photons interact with matter and change direction, the process is called
absorption
scatter
radiation
binding energy
scatter
176
Compton scattering occurs when an incident x-ray photon interacts with a ___ electron.
loosely bound inner-shell
tightly bound inner-shell
loosely bound outer-shell
tightly bound outer-shell
loosely bound outer-shell
177
Which of the following interactions with matter results in a radiograph with a long scale of contrast (low contrast gray image)?
Compton scattering
coherent scatter
photoelectric interactions
photodisintegration
Compton scattering
178
When an x-ray passes through matter, it undergoes a process called
radiation
filtration
attenuation
fluoroscopy
attenuation
179
TRUE/FALSE
During the photoelectric interaction, the incident x-ray photon must be greater than the binding energy of the inner-shell electron.
TRUE
180
Secondary radiation is created after a ________ interaction.
Pairs production
Photoelectric absorption
Photodisintegration
Compton's scatter
Photoelectric absorption
181
TRUE/FALSE
As kVp increases, the total number of photons transmitted without interaction increases.
TRUE
182
During Compton scattering, the incident photon energy is divided between the
ejected electron and the scattered photon
incident photon and the scattered photon
incident photon and the recoil electron
recoil electron and the photoelectron
ejected electron and the scattered photon
183
The electron dislodged during Compton scattering is called the
photoelectron
recoil electron
incident electron
lost electron
recoil electron
184
TRUE/FALSE
Some x-ray photons may pass through matter and not interact with that matter at all.
TRUE
185
Secondary radiation energies are highest for which element?
hydrogen
carbon
barium
oxygen
barium
186
During the photoelectric interaction, as an electron transfers from an outer shell to a vacant inner shell, energy is released in the form of
a characteristic photon
a primary radiation
an incident electron
an incident photon
a characteristic photon
187
During photoelectric absorption, a/an ___ shell electron is typically ejected.
inner-
middle-
outer-
all of the above
inner-
188
An interaction that occurs between very low energy x-ray photons and matter is called ___ scatter.
coherent
classical
unmodified
all of the above
all of the above
189
Unwanted densities caused predominantly by scattered photons are called
kilovoltage
radiation fog
amperage
pair production
radiation fog
190
During the process of attenuation, the x-ray photon may interact with
the nucleus
the entire atom
an orbital electron
all of the above
all of the above
191
The two primary forms of x-ray interaction in the diagnostic range are ____.
Compton scattering and pair production
photoelectric absorption and coherent scattering
Compton scattering and photoelectric absorption
coherent scattering and Thompson scattering
Compton scattering and photoelectric absorption
192
An incident x-ray interacts with an atom without ionization during ____.
photoelectric absorption
Compton scattering
coherent scattering
pair production
coherent scattering
193
An outer-shell electron is ejected and the atom is ionized during ___.
photoelectric interactions
Compton interactions
coherent scattering
pair production
Compton interactions
194
Which x-ray interaction involves the ejection of the K-shell electron?
photoelectric absorption
pair production
Compton interaction
coherent scattering
photoelectric absorption
195
The scattered x-ray from a Compton interaction usually retains ___ of the energy of the incident photon.
none
little
most
all
most
196
As kVp ___, the probability of photoelectric absorption ___.
increases, remains the same
increases, decreases
decreases, decreases
decreases, remains the same
increases, decreases
197
In ___, there is complete absorption of the incident x-ray photon
photoelectric interaction
Compton interaction
coherent scatter
none of the above
photoelectric interaction
198
____ occurs only at the very high energies used in radiation therapy and in nuclear medicine P.E.T. imaging.
photoelectric absorption
coherent scatter
pair production
Compton scatter
pair production
199
Only at energies above 10 MeV can ___ take place.
photodisintegration
pair production
Compton scatter
photoelectric absorption
photodisintegration
200
When the mass density of the absorber is ___, it results in ___ Compton scatter.
decreased, increased
increased, increased
increased, decreased
decreased, no change
increased, increased
201
K-shell binding energy increases with increasing ____.
mass density
kVp
atomic number
mAs
atomic number
202
Which has the greatest mass density?
soft tissue
bone
fat
air
bone
203
Differential absorption in diagnostic imaging is primarily caused by ___.
photoelectric absorption
Compton scatter
pair production
all of the above
photoelectric absorption
204
Differential absorption is dependent on (the) ___.
kVp of the exposure
atomic number of the absorber
mass density of the absorber
all of the above
all of the above
205
Barium is a good contrast agent because of its ____.
low atomic number
high atomic number
light color
low density
high atomic number
206
In the diagnostic range, rare earth scintillators are better absorbers than Calcium Tungstate. This is due to the phenomena know as ________.
Quantum mottle
Annihilation reaction
k-edge effect or absorption
Photoelectric effect
k-edge effect or absorption
207
X-rays transmitted without interaction contribute to ___.
photoelectric absorption
the radiographic image
the image fog
beam attenuation
the radiographic image
208
Compton interactions, photoelectric absorption, and transmitted x-rays all contribute to ___.
image fog (graying of image)
differential absorption (gray vs. Black and white)
patient dose
attenuation
differential absorption (gray vs. Black and white)
209
At energies below 40 keV, the predominant x-ray interaction in bone is ___.
coherent scatter
Compton scatter
photoelectric absorption
photodisintegration
photoelectric absorption
210
If 5% of an incident beam is transmitted through a body part, then 95% of that beam was ___.
absorbed
back-scattered
scattered
attenuated
attenuated
211
The main reason to use a scintillator or phosphor as a capture element is ________.
to increase detail vs. direct exposure film systems
to decrease exposure time vs. direct exposure systems
to decrease patient exposure (dose) vs. direct exposure systems
none of the above
to decrease patient exposure (dose) vs. direct exposure systems
212
The light-emitting efficiency (speed) of the intensifying screen is improved by the ___.
protective coating
reflective layer
added dyes
phosphor afterglow
reflective layer
213
Screen characteristics are determined by the ___.
size of the phosphor crystals
thickness of the phosphor layer
phosphor composition
all of the above
all of the above
214
A phosphorescent material emits light ___.
only from chemical stimulation
for less than a nanosecond
for a period of time after stimulation
only while it is stimulated
for a period of time after stimulation
215
Luminescent material emits light after its outer shell electrons are ___.
excited
ejected
removed
none of the above
excited
216
A screen that emits light after an exposure terminates is exhibiting ___.
conversion efficiency
image noise
screen lag
screen blur
screen lag
217
The intensification factor is a measurement of screen ___.
resolution
speed
noise
quality
speed
218
The ability of an intensifying screen to absorb x-rays is called ___.
intensification factor
quantum mottle
conversion efficiency
detective quantum efficiency
detective quantum efficiency
219
Image noise in increased with increased ___.
detective quantum efficiency (DQE)
conversion efficiency (CE)
both A and B
none of the above
conversion efficiency (CE)
220
Both the isotropic emission of light from screen phosphor crystals and the added reflective layer contribute to ___.
conversion efficiency
image blur
quantum mottle
detective quantum efficiency
image blur
221
As screen speed ______ image detail _______.
increases, increases
increases, decreases
decrease, decrease
decrease, no change
increases, decreases
222
A wrist x-ray required ________ detail and would be best imaged with a ______ speed phosphor.
lower, 100
lower, 400
higher, 400
higher, 100
higher, 100
223
Adding a light absorbing dye to the tube side of a phosphor ___________ the screen speed compared to phosphors with a reflective layer
does not change
decreases
increases
decreases
224
TRUE/FALSE
The tube side of a cassette should have a high Z# material, to prevent excessive attenuation.
FALSE
225
A scintillator can resolve 6 LP/mm, what is the smallest object we can resolve in that image?
0.1mm
.09mm
0.17mm
not enough information to answer
.09mm
226
TRUE/FALSE
The best method of reducing noise when using a very fast speed system, would be to increase the mAs.
TRUE
227
Energy is measured in _____.
a. kilograms
b. joules
c. electron volts
d. B or C
D
| Energy is measured in joules or electron volts
228
Atoms and molecules are the fundamental building blocks of _____.
a. energy
b. radiation
c. matter
d. gravity
C
| Atoms and molecules are the fundamental building blocks of matter.
229
The formula E=mc2 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
C
| The formula E=mc2 is the basis for the theory that led to the development of nuclear power.
230
Radio waves, light, and x-rays are all examples of _____ energy.
a. nuclear
b. thermal
c. electrical
d. electromagnetic
D
| Electromagnetic energy includes radio waves, light, and x-rays as well as other parts of the spectrum.
231
What is the removal of an electron from an atom called?
a. ionization
b. pair production
c. irradiation
d. electricity
A
| The removal of an electron from an atom is called ionization.
232
The energy of x-rays is _____.
a. thermal
b. potential
c. kinetic
d. electromagnetic
D
| X-rays are a form of electromagnetic energy.
233
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
B
| Medical x-ray exposure is the biggest source of man-made radiation.
234
The basic quantities measured in mechanics are _____, _____, and _____.
a. volume, length, meters
b. mass, length, time
c. radioactivity, dose, exposure
d. meters, kilos, seconds
B
| The basic quantities measured in mechanics are mass, length, and time.
235
_____ is a special quantity of radiologic science.
a. Mass
b. Velocity
c. Radioactivity
d. Momentum
C
| Radioactivity is a special quantity of radiologic science.
236
Exposure is measured in units of _____.
a. becquerel
b. sieverts
c. meters
d. grays
D
| Exposure is measured in units of grays.
237
Today, radiology is considered to be a(n) _____ occupation.
a. safe
b. unsafe
c. dangerous
d. high-risk
A
| Today, radiology is considered to be a safe occupation because of effective radiation protection practices.
238
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
B
| ALARA means As Low As Reasonably Achievable.
239
The smallest particle that has all the properties of an element is a(n) _____.
a. neutron
b. proton
c. electron
d. atom
D
| The smallest particle that has all the properties of an element is an atom.
240
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
A positively charged nucleus surrounded by negatively charged electrons in well-defined orbits is the Bohr model of the atom.
241
What are the fundamental particles of an atom?
a. quark, positron, negatron
b. nucleon, electron, proton
c. proton, neutron, quark
d. proton, electron, neutron
D
| The fundamental particles of an atom are the proton, electron, and neutron.
242
An atom in a normal state has an electrical charge of _____.
a. one
b. zero
c. positive
d. negative
B
| An atom in a normal state has an electrical charge of zero.
243
The binding energies, or energy levels, of electrons are represented by their _____.
a. atomic numbers
b. atomic mass units
c. shells
d. isotopes
C
| The binding energies, or energy levels, of electrons are represented by their shells.
244
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
D
| When an atom has the same number of protons as another, but a different number of neutrons, it is called an isotope.
245
An atom that loses or gains one or more electrons is a(n) _____.
a. ion
b. molecule
c. isotope
d. isomer
A
| An atom that loses or gains one or more electrons is an ion.
246
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
B
| The number of electrons in an electron shell is calculated with the formula 2n^2.
247
The innermost electron shell is symbolized by the letter _____.
a. J
b. K
c. L
d. M
B
| The innermost electron shell is symbolized by the letter K.
248
The atomic number of an element is symbolized by the letter _____.
a. A
b. X
c. Z
d. n
C
| The atomic number of an element is symbolized by the letter Z.
249
Two identical atoms which exist at different energy states are called _____.
a. isotopes
b. isomers
c. isotones
d. isobars
B
| Two identical atoms which exist at different energy states are called isomers.
250
During beta emission, an atom releases _____.
a. electrons
b. positrons
c. protons
d. neutrons
A
| During beta emission, an atom releases electrons.
251
The only difference between x-rays and gamma rays is their _____.
a. energy
b. size
c. origin
d. name
C
| The only difference between x-rays and gamma rays is their origin.
252
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
C
| The properties of photons are frequency, wavelength, velocity, and amplitude.
253
The smallest quantity of any type of electromagnetic radiation is a(n) _____.
a. photon
b. electron
c. neutrino
d. quark
A
| The smallest quantity of any type of electromagnetic radiation is a photon.
254
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
C
| The velocity of all electromagnetic radiation is 3 × 10^8 m/s.
255
The rate of rise and fall of a sine wave is called its _____.
a. amplitude
b. frequency
c. wavelength
d. velocity
B
| The rate of rise and fall of a sine wave is called its frequency.
256
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
C
If the wavelength of a beam of electromagnetic radiation increases by a factor of 2, then its frequency must decrease by half.
257
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
D
| The intensity of radiation decreases in inverse proportion to the square of the distance of the object from the source.
258
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
B
If the intensity of light from a flashlight is 4 millilumens (mlm) at a distance of 3 feet using the inverse square law, it will be 1 millilumen at 6 feet.
259
The energy of a photon is directly proportional to its _____.
a. amplitude
b. frequency
c. velocity
d. wavelength
B
| The energy of a photon is directly proportional to its frequency.
260
X-rays are usually identified by their _____.
a. energy
b. velocity
c. wavelength
d. hertz
A
| X-rays are usually identified by their energy.
261
Photons with the highest frequencies have the _____.
a. highest velocity
b. lowest energy
c. longest wavelengths
d. shortest wavelengths
D
| Photons with the highest frequencies have the shortest wavelengths.
262
The smallest unit of electrical charge is the _____.
a. electron
b. proton
c. neutron
d. neutrino
A
| The smallest unit of electrical charge is the electron.
263
Electrification occurs through the movement of _____.
a. protons only
b. protons and electrons
c. electrons only
d. electrons and neutrons
C
| Electrification occurs only through the movement of electrons.
264
Like charges _____ and unlike charges _____.
a. repel, repel
b. attract, attract
c. attract, repel
d. repel, attract
D
| Like charges repel and unlike charges attract.
265
```
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
```
B
Electrostatic force is inversely proportional to the distance between charges, and directly
proportional to the product of the charges.
266
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
D
| The charges on an electrified object are distributed evenly throughout.
267
On the surface of an electrified object, the charges concentrate on the _____.
a. top side
b. underside
c. sharpest curvatures
d. smoothest curvatures
C
| On the surface of an electrified object, the charges concentrate on the sharpest curvature.
268
A _____ is a source of direct current.
a. wall socket
b. battery
c. generator
d. spark
B
| A battery is a source of direct current.
269
What is the unit of electric potential?
a. watt
b. amp
c. volt
d. ohm
C
| The unit of electric potential is the volt.
270
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
D
When an electric potential is applied to a conductor, both an electric current and a magnetic field are
produced.
271
An alternating (AC) current is represented by a _____ line.
a. sinusoidal
b. horizontal
c. vertical
d. descending
```
A
An alternating (AC) current is represented by a sinusoidal line.
```
272
A _____ uses direct current.
a. hair dryer
b. toaster
c. microwave
d. flashlight
D
| A flashlight is battery operated, and batteries use direct current.
273
Alternating current is produced by a _____.
a. battery
b. generator
c. capacitor
d. semiconductor
B
| Alternating current is produced by a generator.
274
What is Ohm’s law?
a. I = V/R
b. V = I/R
c. R = VI
d. I = VR
A
| Ohm’s law is I = V/R.
275
A charged particle in motion creates a(n) _____.
a. negative charge
b. positive charge
c. magnetic field
d. electrostatic charge
C
| A charged particle in motion creates a magnetic field.
276
Electrical power is measured in _____.
a. coulombs
b. amperes
c. volts
d. watts
D
| Electrical power is measured in watts.
277
Rubber and glass are _____.
a. semiconductors
b. conductors
c. insulators
d. superconductors
C
| Rubber and glass are insulators because they are nonconductors.
278
The rotation of electrons on their axis is the property called _____.
a. magnetic force
b. electron spin
c. unified field theory
d. magnetic induction
B
| The rotation of electrons on their axis is the property called electron spin.
279
When a group of dipoles are aligned, they create _____.
a. a magnetic domain
b. paramagnetic material
c. magnetic resonance
d. a north pole
A
| When a group of dipoles are aligned, they create a magnetic domain.
280
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
C
| In the United States, alternating current goes through a complete cycle every 1/60 second.
281
What is the SI unit of magnetic field strength?
a. ampere
b. tesla
c. dipole
d. ohm
B
| The SI unit of magnetic field strength is the tesla or gauss.
282
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
D
The force between magnetic poles is proportional to the product of the magnetic pole strengths,
divided by the square of the distance between them.
283
What type of material can be made magnetic when placed in an external magnetic field?
a. diamagnetic
b. ferromagnetic
c. paramagnetic
d. nonmagnetic
B
| Ferromagnetic material can be made magnetic when placed in an external magnetic field.
284
Like magnetic poles _____ and unlike magnetic poles _____.
a. attract, attract
b. repel, repel
c. repel, attract
d. attract, repel
C
| Like magnetic poles repel and unlike magnetic poles attract.
285
Water is a _____ material.
a. paramagnetic
b. magnetic
c. diamagnetic
d. ferromagnetic
C
| Water is a diamagnetic material.
286
The magnetic intensity of an electromagnet is greatly increased by the addition of a(n) _____ core.
a. wood
b. iron
c. aluminum
d. copper
B
| The magnetic intensity of an electromagnet is greatly increased by the addition of an iron core.
287
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
```
A. on AC but not on DC
288
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
```
D. lower than the input current
289
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
```
E. Nothing
290
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
```
E. Secondary side of the autotransformer
291
The autotransformer has only one:
```
A. Coil
B. Meter
C. Rectifier
D. Switch
E. Turns ratio
```
A. Coil
292
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
```
E. Is required to stabilize voltage
293
The filament transformer:
```
A. Has four windings
B. Increases current
C. Increases voltage
D. Is an autotransformer
E. Must have precision resistors
```
B. Increases current
294
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
```
D. Precision resistors
295
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
```
A. Amplitude
296
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
```
D. Increased x-ray intensity per mAs
297
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
```
A. Electrical insulation
298
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
```
C. 120 pulses per second
299
TRUE/FALSE
As the kinetic energy of the incident electron increases, so does the efficiency of the photon production.
TRUE
300
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
301
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
302
TRUE/FALSE
The electron ejected during a characteristic interaction is also known as the x-ray photon.
FALSE
303
TRUE/FALSE
The creation of a characteristic photon is always the result of a K-shell electron ejection.
FALSE
304
TRUE/FALSE
The creation of a characteristic photon in the diagnostic range is always the result of a K-shell electron ejection.
FALSE
305
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
306
TRUE/FALSE
Inherent filtration is the filtration found within the tube design.
TRUE
307
TRUE/FALSE
In diagnostic radiology, filtration is typically added between the source and the patient.
TRUE
308
Almost all of the kinetic energy of the incident electrons is converted to:
a. a bremsstrahlung photon
b. a characteristic x-ray photon
c. light
d. heat
d. heat
309
What percentage of target interaction results in the production of x-ray photons?
a. 1 percent
b. 50 percent
c. 99 percent
d. 100 percent
a. 1 percent
310
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.
b. ultraviolet radiation.
c. light.
d. sound.
a. infrared radiation.
311
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.
d. the difference between the entering and exiting kinetic energy of the electron.
312
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
c. the force field of the nucleus.
313
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
a. an inner-shell electron.
314
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
b. greater than that of
315
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. a photon of energy.
316
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.
d. the difference between the binding energy of the outer and inner shells between which the electron dropped.
317
At the end of the characteristic cascade, the ____ shell is missing an electron.
a. innermost
b. K
c. outermost
d. characteristic
c. outermost
318
The K-shell can hold a maximum of ____ electrons.
a. 1
b. 2
c. 6
d. 8
b. 2
319
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
c. low-energy x-ray photons
320
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.
a. narrow
321
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.
c. It decreases patient dose.
322
Which of the following materials is/are used as a filter?
a. glass
b. oil
c. aluminum
d. all of the above
d. all of the above
323
All filtration can be expressed in terms of the thickness of:
a. HVL.
b. Pb/Eq.
c. Al/Eq.
d. Sn/Eq..
c. Al/Eq.
324
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.
a. half-value layer.
325
Which of the following is affected by half-layer value?
a. anode construction
b. image quality
c. target longevity
d. patient exposure
d. patient exposure
326
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
c. 3
327
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.
b. The thickest portion of the wedge filter is placed over the less dense part of the patient.
328
True/False?
AC current is required in the x-ray tube, and DC current is required in the transformers
False
329
The filament in the x-ray tube requires ______ amperes to emit electrons, thermionic emission.
0.5-1
1-2
3-5
not enough information to answer
3-5
330
True/False?
The high voltage generator consistes of a high voltage transformer, rectifiers and an autotransformer
False
331
The most likely found incoming line current in a modern radiography system is:
single phase power
three phase power
direct current
~ 60 volts
three phase power
332
The incoming power to a step up transformer is 100 V, 10 A with a turns ration of 250:1.
What is the resulting voltage in this transformer?
25,000 kV
25,000 V
0.4 kV
0.4 V
25,000 V
333
The voltage in the x-ray circuit is adjusted or fine tuned in the __________ for ease and safety.
filament transformer
high voltage transformer
rectifier circuit
autotransformer
autotransformer
334
An induction motor is used in what area of imaging?
rotor rotation
power increase
x-ray table movement
all of the above
rotor rotation
335
A filament transformer with a turns ration of 1:20 provides 3.1 amperes to the filament. What is the current flowing through the primary coil of the transformer?
62
6. 2
1. 55
.155
155
336
True/False
In single phase power systems, the potential never drops to zero.
False
337
When full wave rectification is applied to three phase current, a varying(slight increases and decreases over time) ____ is produced.
current
star
double
voltage
voltage
338
The electrical device used to adjust the mA station is the
autotransformer
stator
switch
precision resistor
precision resistor
339
Nearly all hard wired equipment operates on incoming line voltage of
440 V
120 AC
120 Hz
210 A
440 V
340
All of the following are radiographer operated controls except
kVp selection
generator selection
rotor switch
mA selection
generator selection
341
A step down transformer has ______ windings in the secondary vs. primary side.
less
more
the same
none of the above
less
342
True/False?
The basic x-ray circuit is divided into the main circuit and the anode circuit.
False
343
A single phase full wave rectified system produces _____ pulses per cycle.
1
2
6
12
2
344
True/False?
The mAs in a system controls the quality of the beam.
False
345
At what point in the x-ray circuit is the rectification circuit located?
between the semiconductors and the valve tubes
between the step down transformer and the rheostat
between the step up transformer and the x-ray tube
between the thermionic diode tubes and the x-ray tube
between the step up transformer and the x-ray tube
346
Which of the following transformers has one winding?
Filament transformer
Hi voltage transformer
Autotransformer
none of the above
Autotransformer
347
Which of the following waveforms has the highest efficiency?
Three phase 6 pulse
Three phase 12 pulse
Single phase full wave
All are equal
Three phase 12 pulse
348
The voltage input to an x-ray transformer is most likely _____.
A. 60
B. 220
C. 660
D. >660
B. 220
349
A typical turns ratio in a step-up transformer is most likely _____.
A. 7:1
B. 70:1
C. 700:1
D. 7000:1
C. 700:1
350
Variation of x-ray tube voltage with time is best described as the:
A. ripple
B. pulse frequency
C. uniformity
D. nonlinearity
A. ripple
351
The percentage of ripple of a high-frequency generator is most likely:
A. 1
B. 5
C. 10
D. >10
A. 1
352
The number of pulses per cycle of a half-wave rectified single-phase generator is _____.
A. 1/2
B. 1
C. 2
D. 6
B. 1
353
Which generator has the lowest ripple?
A. single pulse
B. six pulse
C. twelve pulse
D. high-frequency
D. high-frequncy
354
Which generator is most likely to reduce the kVp during an exposure?
A. portable
B. dedicated chest
C. R/F unit
D. Interventional radiology
portable
355
The maximum distance (mm) energetic electrons travel to the x-ray tube tungsten target is most likely _____.
A. 0.05
B. 0.5
C. 5
D. 50
B. 0.5
356
The maximum Bremasstrahlung energy (keV) produced at 80 kVp is most likely _____.
A. 100
B. 80
C. 70
D. 35
B. 80
357
The percentage of Bremasstrahlung radiation at 120 kVp is most likely _____%.
A. 1
B. 10
C. 50
D. 90
D. 90
358
The average Bremsstrahlung energy (keV) produced at 100 kVp is most likely _____.
A. 100
B. 70
C. 55
D. 40
D. 40
359
Tungsten characteristic K-shell x-rays have an energy (keV) of _____.
A. 85
B. 65
C. 35
D. 18
B. 65
360
The percentage of K-shell characteristic x-rays at 55 kVp in a tungsten target is _____.
A. 0
B. 5
C. 10
D. >10
A. 0
361
An x-ray spectrum shows a graph of the number of photons on the vertical axis against _____ on the horizontal axis.
A. kVp
B. keV
C. mAs
D. mA
B. keV
362
The highest intensity in a spectrum from a tungsten target is most likely at the _____.
A. low energies
B. middle energies
C. high energies
D. low and high energies
B. middle energies
363
1 roentgen is approx. equal to _____ mGy.
A. 0.1
B. 1
C. 10
D. 100
C. 10
364
An x-ray tube current is a flow of:
A. electrons
B. protons
C. neutrons
D. ionized atoms
A. electrons
365
Doubling the x-ray tube current, and quadrupling exposure time, increases x-ray tube output by _____.
A. 2x
B. 4x
C. 8x
D. 16x
C. 8x
366
The most likely x-ray tube output (mGy/mAs) 100cm from the x-ray tube focus is most likely _____.
A. 0.05
B. 0.5
C. 5
D. 50
A. 0.05
367
Doubling the mAs increases x-ray production efficiency by ______%.
A. 0
B. 10
C. 50
D. 100
A. 0
368
Doubling the x-ray tube voltage would likely increase the x-ray tube output by _____%.
A. 50
B. 100
C. 200
D. 400
D. 400
369
Doubling the x-ray tube voltage would likely increase the x-ray tube output by _____%.
A. 50
B. 100
C. 200
D. 400
D. 400
370
Doubling the x-ray tube mAs is equivalent to increasing the x-ray tube voltage by _____%.
A. 5
B. 15
C. 50
D. 100
B. 15
371
Which x-ray component is most likely to store the heat generated during an x-ray?
A. anode
B. cathode
C. target
D. filament
A. anode
372
Anode heat capacity is most likely expressed in terms of:
A. heat units
B. watts
C. temperature
D. specific heat
A. heat units
373
How many heat units is 1J?
A. 0.35
B. 0.7
C. 1.35
D. 1.7
C. 1.35
374
Which of the following is not a method for heat dissipation?
A. conduction
B. radiation
C. convection
D. spallation
D. spallation
375
The length of an x-ray tube filament is most likely _____ mm.
A. 0.15
B. 1.5
C. 15
D. 150
B. 1.5
376
X-ray tube filaments are most likely made of:
A. moly
B. silver
C. tungsten
D. lead
C. tungsten
377
The most likely x-ray tube filament current is _____ A.
A. 0.04
B. 0.4
C. 4
D. 40
C. 4
378
The melting point of tungsten targets in x-ray tubes is most likely _____ °C.
A. 34
B. 340
C. 3,400
D. 34,000
C. 3,400
379
The material added to tungsten targets in x-ray tubes is most likely:
A. rhenium
B. silver
C. thorium
D. iron
A. rhenium
380
The target of a mammography x-ray tube is most likely:
A. moly
B. silver
C. aluminum
D. copper
A. moly
381
X-ray tube targets are most likely embedded in the:
A. anode
B. cathode
C. housing
D. focusing grid
A. anode
382
The most likely rotation speed of an anode in a chest radiograph x-ray tube is _____ RPM.
A. 50
B. 500
C. 5,000
D. 50,000
C. 5,000
383
The type of gas in an x-ray tube is most likely:
A. air
B. oxygen
C. nitrogen
D. none (vacuum)
D. none (vacuum)
384
Vaporized tungsten coated on the x-ray tube glass envelope is most likely to result in:
A. arcing
B. leakage radiation
C. gas leaks
D. secondary radiation
A. arcing
385
X-ray production in an x-ray tube is most likely to be emitted towards:
A. anode
B. cathode
C. filament
D. isotropically
D. isotropically
386
The area of an x-ray window is most likely _____ cm^2.
A. 5
B. 50
C. 500
D. 5000
A. 5
387
Radiation that escapes through the protective housing is most likely called:
A. primary
B. secondary
C. leakage
D. scatter
C. leakage
388
The most likely material between the protective housing and the x-ray tube is:
A. oil
B. water
C. air
D. acrylic
A. oil
389
The shape of an aperture diaphragm is least likely a(n):
A. circle
B. square
C. rectangle
D. ellipse
D. ellipse
390
Field size is most severely restricted by use of a(n):
A. cylinder
B. cone
C. diaphragm
D. alignment mirror
A. cylinder
391
The lead thickness of collimator leaves is most likely _____ mm.
A. 0.003
B. 0.03
C. 0.3
D. 3
D. 3
392
The minimum filtration required in a diagnostic x-ray tube is most likely _____ mm Al.
A. 1.0
B. 1.5
C. 2.5
D. 4.0
C. 2.5
393
Added filtration is most likely made of:
A. moly
B. rhenium
C. aluminum
D. silver
C. aluminum
394
The inherent aluminum equivalence of light mirror is most likely _____ mm.
A. 0.01
B. 0.3
C. 1
D. 3
C. 1
395
The small focal spot size in a conventional (W target) x-ray tube is most likely _____ mm.
A. 0.1
B. 0.3
C. 0.6
D. 1.2
C. 0.6
396
The limiting tube current on a small focal spot size is most likely _____ mA.
A. 3
B. 30
C. 300
D. 3000
C. 300
397
The maximum tube current for a typical diagnostic x-ray tube is most likely _____ mA.
A. 100
B. 1,000
C. 10,000
D. 100,000
B. 1,000
398
The maximum tube voltage for a typical diagnostic x-ray tube is most likely _____ kV.
A. 15
B. 150
C. 1,500
D. 15,000
B. 150
399
The most likely exposure time(s) for a synchronous timer would be _____ second.
A. 1/50
B. 1/60
C. 1/70
D. 1/80
B. 1/60
400
The lowest exposure time of an electronic timer is most likely _____ second.
A. 0.001
B. 0.003
C. 0.010
D. 0.030
A. 0.001
401
The most important factor affecting the heel effect is most likely the anode:
A. angle
B. rotation
C. size
D. density
A. angle
402
Which field size (cm x cm) is likely to show the highest heel effect?
A. 35 x 43
B. 30 x 35
C. 24 x 30
D. 18 x 25
A. 35 x 43
403
Off-focus radiation is best controlled by the use of:
A. high kVp
B. high mA
C. collimators
D. a grid
C. collimators
404
X-ray tubes that are used with reduced techniques are most likely to have:
A. longer lives
B. off-focus radiation
C. microprocessor failures
D. repeat rates
A. longer lives
405
Which target will result in the most x-rays, assuming a constant x-ray tube kVp?
A. Mo
B. Rh
C. W
D. no difference (all the same)
C. W
406
1. The reduction in the number and energy of photons as radiation passes through matter is termed:
a. Irradiation
b. Deflection
c. Photoelectrolysis
d. Attenuation
d. Attenuation
407
2. 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
a. Compton interaction
408
3. 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
d. Photoelectric absorption
409
4. 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
b. Pairs production
410
5. 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
a. Inner shell electron
411
6. 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
c. Compton scatter
412
7. 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
c. Photoelectric effect
413
8. 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
a. Incident photon
414
9. Which of the following interactions contributes to image noise?
a. Brems
b. Characteristic
c. Compton
d. Photodisintegration
e. Photoelectric effect
c. Compton
415
10. Compton scatter is:
a. Independent of Z#
b. Inversely proportional to Z#
c. Proportional to E
d. Proportional to Z#2
a. Independent of Z#
416
11. 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
a. Decreases with increasing energy
417
12. 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
a. Absorption of an x-ray
418
13. 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
a. An electron is emitted from an atom
419
14. 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
c. Iodine, BE of 33 keV
420
15. 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
a. E^-3
421
16. 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
a. The photoelectron will have 2 keV of energy
422
17. 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
a. The difference in Z#
423
The formula for computing the generator power is:
A. voltage + current
B. voltage • current
C. voltage / current
D. (voltage / current)^-1
B. voltage • current
