RAD 119 Test #4 Review
An exposure taken at 100 kVp would have a continuous emission spectrum with a maximum energy of ___ kEv. A. 30 B. 69 C. 100 D. 140
100
At 55 kVp, ___ of the x-rays are bremsstrahlung. A. 15% B. 80% C. 100% D. none
100%
In a tungsten-targeted x-ray tube operated at 90 kVp, the most abundant x-ray would be a : A. 10 keV characteristic x-ray B. 12 keV characteristic x-ray C. 30 keV bremsstrahlung x-ray D. 69 keV bremsstrahlung x-ray E. 90 keV bremsstrahlung x-ray
30 keV bremsstrahlung x-ray
In a tungsten-targeted x-ray tube operated at 90 kVp, the most abundant x-ray would be a: A. 10 keV characteristic x-ray B. 12 keV characteristic x-ray C. 30 keV bremsstrahlung x-ray D. 69 keV bremsstrahlung x-ray E. 90 keV bremsstrahlung x-ray
30 keV bremsstrahlung x-ray
Projectile electrons travel from A. anode to cathode B. cathode to anode C. target to patient D. inner shell to outer shell
cathode to anode
Which of the following factors primarily affects the low-energy side of the x-ray emission spectra? A. exposure time B. filtration C. tube current D. tube voltage E. voltage waveform
filtration
Inherent filtration
filtration that is a result of the composition of the tube and housing (0.5 mm)
Approximately ___ of the kinetic energy of the projectile electrons is converted to x-rays at the target. A. 1% B. 10% C. 50% D. 99%
1%
Gold is sometimes used as the target material in special types of radiation-producing systems. Its electron-binding energies are as follows: K-Shell: 81 keV; L-Shell: 14 keV; M-Shell: 3 keV; N-Shell: 1 keV. Which of the following characteristic x-rays would be produced with operation at 90 kVp? A. 12 keV B. 67 keV C. 87 keV D. 76 kEv E. 90 keV
67 keV
The useful characteristic x-rays from tungsten targets are ___ x-rays. A. K-shell B. L-shell C. M-shell D. N-shell
K-shell
When a bremsstrahlung x-ray produced? A. a projectile electron is absorbed B. a projectile electron loses energy C. a target electron is displaced D. a target electron is excited E. a target electron is ionized
a projectile electron loses energy
Which of the following factors explains the low number of x-rays emitted at low energy? A. added filtration B. the glass envelope of the x-ray tube C. the kVp D. the mAs enclosing the x-ray tube E. the product of tube current and exposure time
added filtration
Which of the following factors principally accounts for the reduced x-ray intensity at low energy? A. added filtration B. beam collimation C. atomic number of the target material D. energy spectrum of the projectile electrons E. voltage waveform
added filtration
Type of material used in filters
aluminum
The shift of the characteristic x-ray spectrum to higher energy occurs because of which of the following? A. a decrease in voltage ripple B. a decrease in kVp C. a higher atomic number filter D. an increase in kVp E. an increase in target atomic number
an increase in target atomic number
Added filtration
any filtration that occurs outside the tube and housing before the image receptor (1.0 mm)
Characteristic x-rays: A. are characteristic of target Z B. are characteristic of the filter material C. are characteristic of the voltage waveform D. have velocity varying from zero to the speed of light E. vary in energy as kVp is varied
are characteristic of target Z
The energy of characteristic x-rays increases with increasing: A. filtration B. atomic mass of target material C. atomic number of target material D. kVp E. voltage waveform
atomic number of target material
The wavelength of an x-ray: A. becomes longer as projectile electron kinetic energy is receded B. becomes longer with increasing projectile electron energy C. is longer than that of ultraviolet light D. is the longest when the projectile electron loses all its kinetic energy E. is proportional to its frequency
becomes longer as projectile electron kinetic energy is receded
An increase in mAs results in an increase in: A. average x-ray energy B. both characteristic and bremsstrahlung x-rays C. minimum wavelength D. only bremsstrahlung x-rays E. only characteristic x-rays
both characteristic and bremsstrahlung x-rays
Normally, the x-ray emission spectrum contains: A. both characteristic and bremsstrahlung x-rays B. both photoelectric and Compton x-rays C. only bremsstrahlung x-rays D. only characteristic x-rays E. only discrete lines
both characteristic and bremsstrahlung x-rays
Most of the x-rays produced at the target are _____. A. bremsstrahlung B. characteristic C. gamma D. beta
bremsstrahlung
If radiographic technique is 74 kVp/80 mAs: A. bremsstrahlung x-ray energy increases if the voltage is increased to 84 kVp B. bremsstrahlung x-rays are emitted at discreet energies C. bremsstrahlung x-rays have a maximum energy of 80 keV D. characteristic x-ray energy increases if the voltage is increased to 84 kVp E. characteristic x-rays are emitted only at 74 kEv
bremsstrahlung x-ray energy increases if the voltage is increased to 84 kVp
Useful characteristic x-rays are produced in tungsten: A. by excitation of a K-shell electron B. by removal of a K-shell electron C. by ionization of an L-shell electron D. when a valence electron is removed E. when the projectile electron interacts with an outer-shell electron
by removal of a K-shell electron
Bremsstrahlung radiation is produced by: A. conversion of projectile electron kinetic energy to electromagnetic energy B. conversion of target electron kinetic energy to electromagnetic energy C. intrashell electron transitions D. projectile electron-target electron interaction E. target election-nuclear interaction
conversion of projectile electron kinetic energy to electromagnetic energy
Both the shape and the position of the characteristic x-ray emission spectrum: A. are described by the number of projectile electrons B. represent projectile electron energy C. can be described as continuous D. correspond to target electron binding energies E. result from nuclear interaction
correspond to target electron binding energies
Character x-radiation is related to the: A. difference between K- and L-shell binding energy B. energy required to eject K-shell electrons C. energy to eject L-shell electrons D. number of electrons E. number of K-shell electrons
difference between K- and L-shell binding energy
How would the characteristic spectrum change if operation were at 64 kVp/200 mA/20 ms? The characteristic x-ray spectrum would: A. decrease in height B. disappear C. increase in height D. shift slightly to the left E. shift slightly to the right
disappear
Bremsstrahlung x-rays are produced only at: A. discreet energies B. energies above characteristic x-rays C. energies below characteristic x-rays D. energies up to projectile electron energy E. projectile electron energy potential
energies up to projectile electron energy
Molybdenum has a lower atomic number than tungsten; therefore, the molybdenum x-ray emission spectrum: A. extends to higher energies B. extends to lower energies C. has higher amplitude D. has higher-energy characteristic x-rays E. has lower amplitude
has lower amplitude
The amplitude of the bremsstrahlung x-ray emission spectrum: A. approaches maximum at an energy equal to the kVp B. approaches maximum at zero energy C. has maximum value at energy approximately one third of the kVp D. has maximum value of energy at equal to the kVp E. is enhanced with filtration
has maximum value at energy approximately one third of the kVp
What is produced with a projectile electron excites an outer-shell electron? A. bremsstrahlung x-ray B. characteristic x-ray C. energy D. heat E. photoelectric x-ray
heat
An increase in kVp would _____ the _____ of the emission spectrum. A. increase, position only B. increase, amplitude only C. increase, amplitude and position D. not affect, amplitude and position
increase, amplitude and position
An increase in mAs would _____ the _____ of the emission spectrum. A. increase, position only B. increase, amplitude only C. increase, amplitude and position D. not affect, amplitude and position
increase, amplitude only
The efficiency of x-ray production is: A. approximately 5% B. greater than that of heat production C. in excess of 5% D. independent of the tube current E. independent of the tube voltage
independent of the tube current
The kinetic energy of the projectile electron in an x-ray tube: A. causes excitation in the vacuum of the x-ray tube B. causes ionization in the vacuum of the x-ray tube C. is about 1% efficient in the production of x-rays D. is converted into mass E. is totally converted into x-ray energy
is about 1% efficient in the production of x-rays
The output intensity of an x-ray tube: A. increases when filtered B. is limited by the K-shell binding energy C. is monoenergetic D. often is measured in curies E. is primarily due to bremsstrahlung x-rays
is primarily due to bremsstrahlung x-rays
When a projectile electron enters a target atom and interacts with the nuclear force field: A. it decreases in velocity B. it increases in velocity C. it ionizes the atom D. it ionizes the nucleus E. it removes an inner-shell electron
it decreases in velocity
How would the bremsstrahlung spectrum change if operation at 80 kVp/200 mA/100 ms were changed to 64 kVp/200 mA/100 ms? A. it would remain the same, but the amplitude would decrease B. it would remain the same, but the amplitude would increase C. it would shift to the left, and the amplitude would be lower D. it would shift to the left, and the amplitude would be higher E. it would shift to the right, and the amplitude would be higher
it would shift to the left, and the amplitude would be lower
The efficiency of x-ray production increases as _____ increases. A. mA B. kVp C. time D. both a and b
kVp
During an exposure, most of the _____ energy of the projectile electrons is converted to _____. A. kinetic, x-rays B. x-ray, kinetic C. kinetic, heat D. heat, kinetic
kinetic, heat
The amplitude of the emission spectrum with a _____ generator is _____ it is with a three-phase generator. A. lower, single-phase B. lower, high frequency C. higher, single-phase D. the same, single phase
lower, single-phase
The quantity of bremsstrahlung radiation increases proportionately with increased _____. A. kVp B. mAs C. filtration D. rotor speed
mAs
When projectile electron energy is increased: A. characteristic x-ray energy decreases B. characteristic x-ray energy increases C. more bremsstrahlung x-rays are produced D. more bremsstrahlung x-rays are produced, but only at high energies E. more bremsstrahlung x-rays are produced, but only at low energies
more bremsstrahlung x-rays are produced
If an average radiographic technique is used: A. excitation of the target is approximately 50% B. ionization of the target is almost complete C. maximum-energy x-ray is the electron binding energy D. most x-rays are bremsstrahlung E. most x-rays are characteristic
most x-rays are bremsstrahlung
A diagnostic x-ray beam contains: A. bremsstrahlung only B. mostly bremsstrahlung x-rays, with some characteristic x-rays C. mostly Compton x-rays, few bremsstrahlung x-rays, and some pair production x-rays D. some Compton x-rays, some bremsstrahlung x-rays, and some pair production x-rays E. some photoelectric x-rays
mostly bremsstrahlung x-rays, with some characteristic x-rays
Which of the following electron transitions results in the most useful bremsstrahlung x-ray? A. L to K B. M to K C. M to L D. O to K E. none of the above
none of the above
To construct an x-ray emission spectrum, one must know the: A. kVp and mAs B. mAs and x-ray frequency C. number of x-rays and each energy interval D. projectile electron number and energy interval E. target element and filtration
number of x-rays and each energy interval
Most of the heat generated at the target is due to A. inner-shell ionization B. outer-shell excitation C. nucleus bombardment D. k x-rays
outer-shell excitation
Bremsstrahlung x-rays produced in a tungsten-targeted x-ray tube: A. are all diagnostically useful B. are generally less useful than characteristic x-rays C. are less intense than characteristic x-rays D. are less intense than if produced in molybdenum E. outnumber characteristic x-rays
outnumber characteristic x-rays
The continuous x-ray emission spectrum principally depends on which of the following: A. exposure time B. filtration C. mAs D. projectile electron energy E. target material
projectile electron energy
X-rays are produced when: A. electric current flows through the x-ray tube filament B. projectile electrons bounce off the cathode C. projectile electrons interact with target atoms D. the target angle is sufficiently large E. the x-ray tube filament is heated to thermionic emission
projectile electrons interact with target atoms
The ___ of the x-ray beam is higher when the peak of the emission spectrum is further to the ___. A. quality, right B. quantity, right C. quality, left D. quantity, left
quality, right
An increase in kVp results in an increase in: A. Characteristic x-ray energy B. only the bremsstrahlung x-ray emission spectrum C. only the characteristic x-ray emission spectrum D. radiation quality E. minimum wavelength
radiation quality
How does added filtration affect the emission spectrum? A. increased amplitude and a shift to the right B. reduced amplitude and a shift to the left C. reduced amplitude and a shift to the right
reduced amplitude and a shift to the right
Characteristic x-rays are produced by A. braking electrons B. excitation of outer shell electrons C. nuclear fragmentation D. released binding energy
released binding energy
Which of the following projectile electron-target interactions results in x-ray emission? A. excitation of inner-shell electron B. excitation of outer-shell electron C. removal of inner-shell electron D. removal of nucleus E. removal of outer-shell electron
removal of inner-shell electron
Bremsstrahlung x-rays are produced by ___ at the target. A. outer shell excitation B. slowing electrons C. K-shell interactions D. L-shell interactions
slowing electrons
When a tungsten-targeted x-ray tube is operated at 68 kVp: A. K-shell characteristic x-rays can be produced B. L-shell x-rays cannot be produced C. one possible K-shell characteristic x-ray will have 12 keV of energy D. some projectile electrons may have 68 keV of energy E. some projectile electrons may have 75 keV of energy
some projectile electrons may have 68 keV of energy
Conditions necessary for x-ray production
source of electrons, target (anode), high potential difference, sudden deceleration of projectile electrons
In general, when changes are made that affect the x-ray emission spectrum and the: A. amplitude increases, the radiation quantity decreases B. line spectrum moves, voltage waveform has changed C. spectrum shifts to the left, a higher-quality beam is emitted D. spectrum shifts to the left, more filtration was used E. spectrum shifts to the right, a more penetrating beam is emitted
spectrum shifts to the right, a more penetrating beam is emitted
The efficiency of bremsstrahlung x-ray production increases with increasing: A. collimation B. filtration C. mA D. SID E. target atomic number
target atomic number
The characteristic x-ray emission spectrum principally depends on which of the following? A. filtration B. kVp C. mAs D. projectile electron energy E. target material
target material
The discrete portion of the x-ray emission spectrum would change position with a change in _____. A. kVp B. target material C. voltage ripple D. both a and b
target material
When a bremsstrahlung x-ray is emitted: A. a projectile electron is absorbed B. an inner-shell electron is removed from the target atom C. an outer-shell electron is removed from the target atom D. this results from the conversion of kinetic energy E. the target atom is ionized
this results from the conversion of kinetic energy
If an x-ray emission spectrum represented operation at 85 kVp with a tungsten target: A. at 85 kEv, the number of projectile electrons would be maximum B. bremsstrahlung x-rays would be most intense at 85 keV C. the K-characteristic x-ray emission would occur at 69 keV D. x-rays representing maximum frequency would occur at 69 keV E. x-rays representing minimum wavelength would occur at 0 keV
the K-characteristic x-ray emission would occur at 69 keV
The intensity of x-ray exposure is best represented by: A. the amplitude of the bremsstrahlung x-ray emission spectrum B. the amplitude of the characteristic x-ray emission spectrum C. the amplitude of the highest emission spectrum D. the area under the emission spectrum E. the energy range of the emission spectrum
the area under the emission spectrum
When characteristic x-rays are produced, the energy of the x-rays is characteristic of: A. the atomic number of the filter B. the atomic number of the target C. the outer-shell electron binding energy D. the mass of filtration E. the orientation of the target
the atomic number of the target
If an x-ray emission spectrum represente operation at 26 kVp with a molybdenum target: A. K-characteristic x-rays would not be produced B. more characteristic bremsstrahlung x-rays would be emitted C. the characteristic radiation would have an energy of approximately 19 keV D. maximum frequency x-rays would have an energy of 17 keV E. minimum wavelength x-rays would have an energy of keV
the characteristic radiation would have an energy of approximately 19 keV
If radiographic technique in a tungsten target at 60 kVp/80 mAs is changed to 80 kVp/80 mAs: A. additional filtration is required B. bremsstrahlung x-ray intensity remains unchanged C. characteristic x-ray intensity remains unchanged D. the number of projectile electrons increases E. the number of x-rays produced increases
the number of x-rays produced increases
The x-ray emission spectrum is a plot of: A. mAs versus kVp B. the number of electrons versus energy C. the number of x-rays versus energy D. x-rays and electrons emitted from cathode atoms D. x-rays and electrons emitted from target atoms
the number of x-rays versus energy
In bremsstrahlung x-ray production: A. the projectile electron is bound to tungsten B. the projectile electron is from the cathode C. the target electron exits as a free electron D. the target electron is from the cathode E. the target electron is ionized
the projectile electron is from the cathode
Total filtration
the sum of inherent and added filtration and mirror (1.0 mm) (2.5 mm total)
Which of the following statements applies to the x-ray emission spectrum? A. adding filtration affects characteristic x-ray energy B. adding filtration affects the minimum wavelength C. adding filtration increases entrance skin exposure D. the target material affects the amplitude of bremsstrahlung x-rays E. the target material affects the minimum wavelength
the target material affects the amplitude of bremsstrahlung x-rays
The area under the curve of the x-ray emission spectrum represents: A. the average energy of the x-rays B. the average number of x-rays per unit of energy C. the total energy of the x-rays D. the total number of x-rays E. total exposure
the total number of x-rays
The x-ray emission spectrum represents: A. projectile electron energy B. atomic mass and number of the target atom C. electron binding energy of target material D. total x-ray beam filtration E. x-rays emitted from the x-ray tube
x-rays emitted from the x-ray tube