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WorksheetsImaging II: 1313 Fall Final Review: 1
Total questions: 112
Worksheet time: 56mins
Which step directly causes electrons to be released from the filament in an X‑ray tube?
Increasing current causing the heating of tungsten on the filament
Selecting kVp at the control console
Reducing tube current substantially
Increasing the voltage across the tube
What primarily attracts electrons across the tube toward the target?
The thermal expansion of tungsten
The positively charged anode potential
The rotation speed of the target
The vacuum pressure inside housing
Bremsstrahlung radiation in an X‑ray tube is produced when an incident electron does what near the nucleus?
Fuses with a proton irreversibly
Captures a free neutron transiently
Slows or changes direction significantly
Maintains constant straight velocity
Characteristic radiation results after which initial interaction in the target atom?
Ejection of a K‑shell electron
Emission from the filament coil
Excitation of a valence electron
Ionization of the vacuum molecules
Which statement best contrasts the photon energies from Bremsstrahlung versus characteristic radiation?
Both depend only on filament temperature
Bremsstrahlung is polyenergetic; characteristic is discrete
Both produce identical monoenergetic spectra
Bremsstrahlung is discrete; characteristic is polyenergetic
Approximately what fraction of the incident electron kinetic energy becomes useful X‑rays at the target?
About ninety percent of the energy
About half of the energy
About one percent of the energy
About ten percent of the energy
If the target material changes from tungsten to a different element, which emission is most affected?
Anode electrostatic attraction
Characteristic photon energy lines
Bremsstrahlung continuous spectrum
Filament thermionic emission
A student increases tube voltage while keeping filament current constant. Which outcome mainly increases at the anode?
Cooling rate of the oil bath
Rotational torque on stator
Thermionic electrons boiled off
Electron acceleration toward target
Which factor primarily determines the maximum photon energy in an x‑ray beam?
Exposure time only
kVp at the tube
mAs at the console
Focal spot size
Beam quality in diagnostic imaging refers to which property of the x‑ray beam?
Spatial resolution of images
Tube heat loading capacity
Penetrating ability of photons
Total number of photons
Which setting controls beam quantity in routine radiography?
Filtration thickness only
mAs set by technologist
kVp at the generator
Anode angle selection
What happens to average photon energy when kVp is increased while other factors are held constant?
It becomes highly variable
It remains exactly unchanged
It increases on average
It decreases slightly overall
Increasing filtration typically produces which effect on the x‑ray spectrum?
Lowers average photon energy overall
Raises average photon energy overall
Removes only high‑energy photons
Creates more low‑energy photons
In the anode heel effect, where is beam intensity greatest across the field?
Uniform across the entire field
Toward the cathode side
Directly at the central ray
Toward the anode side
A shoulder radiograph involves unequal thickness across the field. How should you position the cathode‑anode axis to use the anode heel effect to your advantage?
Place the anode over the thicker side
Place the cathode over the thicker side
Center the beam on the thinner side
Rotate the tube to reduce filtration
Which component of the X-ray tube produces electrons for imaging?
Glass envelope surrounding tube
Oil inside the protective housing
Target on the rotating anode
Filament in the cathode assembly
What is the main role of the focusing cup in the X-ray tube?
Heats the filament to emit electrons
Provides vacuum so electrons travel
Narrows the electron cloud toward anode
Converts electrons into x-ray photons
Why is the anode designed to rotate during operation?
Reduces leakage radiation from housing
Maintains the vacuum around filament
Spreads heat to increase heat capacity
Accelerates electrons toward target
What is the function of the stator in a rotating anode tube?
Metal cup that shapes electron beam
External electromagnets that rotate rotor
Stationary target for x-ray production
Insulating oil that cools components
Where are x-rays produced within the tube?
In the oil around the housing
Within the focusing cup cavity
Inside the glass envelope body
At the target where electrons strike
What is the primary purpose of the glass envelope in an X-ray tube?
Contains oil for thermal dissipation
Acts as the target for electron impact
Provides structural support for housing
Maintains a vacuum for electron travel
Which statement best explains the role of oil and housing in tube operation?
Increase x-ray photon energy output
Focus electrons onto a smaller spot
Create the vacuum around electrodes
Provide electrical insulation and cooling
A tube produces excessive heat at one spot on the anode. Which component is most likely not functioning as intended?
Stator that provides electromagnets
Glass envelope that maintains vacuum
Filament that emits electrons
Rotating anode that spreads heat
In digital radiography, what primarily determines displayed image brightness?
Look-up table and processing algorithms
Milliamperage and exposure time directly
Kilovoltage peak at the tube only
Patient thickness without processing
Quantum mottle is most likely when which exposure condition occurs?
Too many photons saturating the detector
Scatter completely eliminated by collimation
Too few incident photons reaching detector
Excessive post-processing edge enhancement
If kVp is increased while other factors are constant, image contrast generally becomes:
Random with unpredictable gray scale
Unchanged with any gray scale
Higher with a shorter gray scale
Lower with a longer gray scale
mAs has what relationship with image receptor exposure in radiography?
Quadratically related to receptor exposure
Directly proportional to receptor exposure
Inversely proportional to receptor exposure
Unrelated to receptor exposure
Which description best matches long-scale contrast on a radiographic image?
Black-and-white with minimal midtones
Few grays with very high contrast
Many grays with lower subject contrast
Edges enhanced with processing only
Which technique combination most commonly produces long-scale contrast?
Any kVp when mAs is very high
High kVp with increased scatter present
Low kVp with reduced scatter present
Moderate kVp with no effect from scatter
A radiograph shows very high contrast with few shades of gray. Which exposure factor set most likely produced it?
Low kVp with effective scatter control
High mAs with unchanged kVp
High kVp with abundant scatter
Low mAs with unchanged kVp
To reduce visible quantum noise without changing contrast, which adjustment is most appropriate?
Apply only a steeper LUT curve
Increase mAs while keeping kVp constant
Decrease kVp while keeping mAs constant
Increase SID without other changes
Which factor most directly causes motion blur in radiographic images?
Motion during exposure time
Low subject contrast range
High detector pixel density
Wide exposure latitude
Which change increases image magnification most effectively, all else equal?
Reduce patient thickness
Increase OID slightly
Center the x‑ray tube
Increase SID greatly
Size distortion in radiography primarily results from which condition?
Magnification due to SID or OID changes
Grid cutoff from misalignment
Quantum mottle from low mAs settings
Beam hardening at high kVp levels
Shape distortion such as elongation or foreshortening is mainly caused by what?
Improper alignment of tube, part, or IR
Excessive patient thickness only
Insufficient exposure time settings
Using a high grid ratio device
According to the inverse square law, if the source‑to‑image distance doubles, what happens to beam intensity at the image receptor?
It remains exactly the same
It becomes four times as intense
It becomes half as intense
It becomes one‑fourth as intense
A radiograph shows blur from patient motion. Which simple procedural change best improves spatial resolution without altering dose?
Increase kVp moderately
Increase SID slightly
Add a higher ratio grid
Shorten exposure time
You must maintain receptor exposure while increasing SID from 80 cm to 160 cm. Which adjustment matches the exposure maintenance concept?
Increase mAs by a small amount
Increase mAs by a factor of four
Decrease mAs by a factor of four
Keep mAs exactly the same
Which imaging factor is primarily controlled by mAs?
Amount of scatter generation
Subject contrast between tissues
X-ray beam penetration depth
Image receptor exposure quantity
Increasing kVp most directly increases which property of the x-ray beam?
Focal spot temperature
Photon penetration ability
Anode rotation speed
Exposure time duration
What is the typical effect of higher kVp on image contrast in radiography?
Lowers subject contrast
Raises subject contrast
Eliminates subject contrast
Leaves subject contrast unchanged
Filtration primarily removes which component from the x-ray beam?
Characteristic photons
Low-energy photons
High-energy photons
Backscatter photons
What happens to beam quality when filtration is increased?
Beam becomes harder overall
Beam becomes softer overall
Beam intensity becomes random
Beam wavelength becomes longer
Half-Value Layer (HVL) is defined as the thickness of material that does what?
Reduces beam intensity by half
Doubles beam intensity output
Halves patient exposure time
Eliminates scatter completely
HVL is used primarily as a measure of which characteristic?
Beam quality or hardness
Detector efficiency rating
Beam quantity per second
Tube heat capacity
What is the main purpose of beam restriction using collimation?
Reduce scatter reaching the detector
Increase photon penetration power
Decrease exposure time needed
Improve tube heat dissipation
What is the primary function of the autotransformer in an X-ray circuit?
Selects kVp before high voltage
Increases current to heat filament
Converts AC to DC current
Provides backup to prevent overexposure
A step-up transformer in an X-ray unit mainly does which of the following?
Increases voltage to produce high kVp
Decreases voltage to increase current
Stabilizes ripple to reduce noise
Switches AC direction during exposure
The step-down transformer is used in the filament circuit primarily to:
Increase current to heat the filament
Increase voltage for the X-ray tube
Rectify AC into DC pulses
Limit exposure by timing cutoff
What is the role of a rectifier in an X-ray generator?
Converts alternating current to direct current
Raises voltage to shorten exposure time
Selects the desired kilovoltage peak value
Monitors output to prevent overexposure
Which component prevents patient overexposure if the set exposure fails to terminate?
Step-up transformer in primary
Backup timer in the generator
Rectifier in the tube circuit
Autotransformer in the control panel
Compared to single-phase generators, three-phase generators are generally:
Most efficient with shortest exposures
Less efficient with higher ripple
Equally efficient with similar ripple
More efficient with steadier output
Where are AEC ionization chambers positioned in a radiographic system?
Behind the control panel console
Inside the X-ray tube housing
Adjacent to the collimator assembly
Between patient and image receptor
What is the primary function of the AEC detector during an exposure?
Calibrates generator before imaging
Measures patient thickness for mAs
Selects kilovoltage automatically
Detects radiation and ends exposure
Which factor most critically influences AEC performance and image quality?
Use of additional filtration
Higher source-to-image distance
Increased tube current setting
Precise patient positioning
Using AEC, what manual selection does the technologist typically not set?
Exposure time selection
Focal spot size choice
Grid ratio selection
Source-to-image distance
AEC density controls primarily adjust which image characteristic?
Collimator field size
Tube potential waveform
Patient entrance dose
Built-in optical density
Which combination best applies the ALARA principles during radiographic procedures?
Minimize time, reduce distance, avoid shielding
Minimize time, maximize distance, use shielding
Increase time, reduce distance, avoid shielding
Maintain time, ignore distance, limited shielding
In radiology, what does shielding typically refer to for staff and patients?
Lead protection devices
Concrete ceiling panels
Aluminum beam filters
Plastic scatter curtains
Secondary radiation consists of which components?
Scatter plus leakage
Primary beam photons
Backscatter only
Leakage from generator
Primary radiation is best described as which source?
Direct beam from the tube
Scatter from the patient
Transmission through table
Leakage from housing
What is the annual whole-body occupational dose limit in diagnostic radiography?
5 mSv per year
150 mSv per year
1 mSv per year
50 mSv per year
What is the monthly fetal dose limit for pregnant workers?
0.5 mSv per month
5 mSv per month
1 mSv per month
50 mSv per month
Which monitoring device uses aluminum oxide and is read by laser stimulation?
Film badge dosimeter
Thermoluminescent dosimeter
Electronic dosimeter
Optically stimulated luminescence
Which personal dosimeter requires heating to emit light proportional to dose?
Thermoluminescent dosimeter
Optically stimulated luminescence
Film badge dosimeter
Electronic dosimeter
Which instrument measures exposure rate rather than merely detecting presence?
Electronic dosimeter
Scintillation detector
Geiger-Müller counter
Ion chamber survey meter
Which barrier is designed to be struck by the primary beam in a radiography room?
Primary barrier surface
Secondary barrier surface
Mobile rolling barrier
Scatter-only barrier
Which grid error most likely produces a uniform loss of receptor exposure across the image?
Off-level grid positioning
Off-center beam alignment
Upside-down grid placement
Off-focus source distance
A radiograph shows one-sided cutoff with adequate exposure on the opposite side. Which error best explains this appearance?
Off-level grid error
Off-center grid error
Moiré interference pattern
Off-focus grid error
Cutoff is most pronounced at the lateral edges while the center remains acceptable. Which situation is most consistent with this finding?
Grid used at wrong SID
Grid placed upside-down
Grid tilted relative to beam
Detector sampling aliasing
Severe exposure loss at both edges with a narrow band of exposure centrally is characteristic of which grid problem?
Off-level grid error
Off-center grid error
Upside-down grid error
Off-focus grid error
A stationary grid used with computed radiography produces a wavy, repeating pattern over the image. What is this artifact called?
Moiré effect
Quantum mottle
Saturation banding
Anode heel
Which action best reduces scatter reaching the receptor when imaging a body part thicker than 10 cm?
Increase exposure mAs
Use a radiographic grid
Open the collimators
Lower tube filtration
You increase kVp to improve penetration for a large patient. To maintain receptor exposure, which complementary change is most appropriate?
Reduce mAs appropriately
Decrease SID slightly
Increase collimation width
Remove the anti-scatter grid
When increasing the source-to-image distance (SID) while keeping other factors constant, what adjustment maintains receptor exposure?
Increase mAs according to distance
Center off the grid slightly
Add an air-gap without grid
Decrease kVp by small steps
Which subatomic particle carries a negative charge in an atom?
Electron with negative charge
Positron with positive charge
Proton with positive charge
Neutron with neutral charge
Two atoms are isotopes when they have the same atomic number but what differs?
Number of neutrons thus mass
Electron arrangement only
Number of shells thus size
Number of protons thus charge
An ion forms when an atom has what relationship between protons and electrons?
Equal protons and electrons
Unequal protons and electrons
More neutrons than protons
More shells than electrons
Which change will increase electron binding energy within an atom?
Reducing nuclear charge shielding
Placing electrons farther out
Decreasing atomic number Z
Increasing atomic number Z
Compared with an electron in the L shell, an electron in the K shell generally has what?
Lower binding energy overall
Equal binding energy overall
No binding energy overall
Higher binding energy overall
What is ionization in atomic physics?
Adding a neutron to the nucleus
Removing an electron from an atom
Exciting an electron to a higher shell
Converting a proton into a neutron
Which statement best reflects the law of conservation of energy?
Energy can be created from heat
Energy changes form but is conserved
Energy is destroyed in reactions
Energy only exists as kinetic energy
Which statement best describes magnetic poles?
Poles have no effect on nearby materials
All poles attract regardless of orientation
Like poles attract while unlike poles repel
Like poles repel while unlike poles attract
Magnetic flux in this context refers to which idea?
A measure of magnetic field strength
The speed of electron motion
Heat transferred by conduction
A unit of electrical resistance
Which set lists types of magnets correctly?
Static magnets and kinetic magnets
Thermal magnets and acoustic magnets
Natural magnets and artificial magnets
Chemical magnets and nuclear magnets
What microscopic change creates magnetism in a material?
Expansion of crystal lattice
Alignment of magnetic domains
Increase of thermal vibrations
Accumulation of electric charge
Which combination is required to induce an emf in a circuit?
Magnetic field, conductor, and relative motion
Static charge, dielectric, and capacitor
Battery, resistor, and closed switch
High voltage, vacuum, and insulator
According to Faraday’s law for a coil, the induced current depends on which factors?
Field strength, speed, angle, and number of turns
Wire color, coil shape, and ambient noise
Battery polarity, fuse rating, and humidity
Mass density, wavelength, and refractive index
Lenz’s law determines which feature of an induced current?
Its magnitude equals the flux value
Its direction opposes the flux change
Its frequency matches the field lines
Its phase leads the applied voltage
Which statement best describes a step-up transformer?
It increases voltage and decreases current
It increases current and decreases voltage
It keeps voltage and current unchanged
It decreases both voltage and current
In an ideal transformer, the turns ratio primarily determines which quantity change between primary and secondary coils?
Frequency change of the output
Core permeability over time
Voltage change between the two coils
Resistance change of the windings
Which loss in a transformer is mainly due to circulating currents induced in the core material?
Copper loss in the windings
Hysteresis loss from magnetization
Leakage flux loss in air
Eddy current loss in the magnetic core
Which component is associated with an AC generator for transferring current to the external circuit?
Field rheostat controller
Slip rings on the rotating armature
Commutator with split rings
Brushless diode rectifier
A DC generator differs from an AC generator primarily because it uses which device to deliver unidirectional current?
A commutator with split segments
A synchronous rotor coil
Two continuous slip rings
An induction stator cage
What is the fundamental energy conversion performed by an electric motor?
Chemical energy into magnetic fields
Thermal energy into electrical charge
Mechanical energy into electrical output
Electrical energy into mechanical rotation
In an induction motor, which part is driven to rotate by the induced magnetic field interaction?
The slip rings on the axle
The commutator ring assembly
The rotor attached to the shaft
The stationary outer stator
As electromagnetic frequency increases, what happens to wavelength and photon energy?
Wavelength increases, energy decreases
Wavelength decreases, energy increases
Wavelength decreases, energy decreases
Wavelength increases, energy increases
Which statement best describes X-rays in the electromagnetic spectrum?
High energy, ionizing radiation
Moderate energy, partly ionizing radiation
Variable energy, non-ionizing radiation
Low energy, non-ionizing radiation
Wave–particle duality means photons behave as what?
Only particles in all conditions
Particles and waves depending on context
Only waves in all conditions
Neither waves nor particles ever
Which characteristic defines a stochastic radiation effect?
Severity increases with dose
Always causes immediate symptoms
Has a clear threshold dose
Probability increases with dose
Which outcome is a typical example of a stochastic effect?
Cataract at deterministic threshold
Radiation-induced cancer years later
Skin erythema after fluoroscopy
Temporary sterility at high dose
Deterministic effects are best described by which feature?
Always genetic with no tissue damage
Have a threshold; severity rises with dose
Independent of absorbed dose amount
No threshold, random occurrence
Why is ionizing radiation dangerous at the cellular level?
It neutralizes free radicals safely
It blocks non-ionizing wavelengths
It causes ionization leading to mutations
It only heats tissues slightly
What is the primary purpose of an anti-scatter grid in radiography?
Shorten exposure time significantly
Magnify the anatomical structures
Remove scatter to improve contrast
Increase patient dose intentionally
How is grid ratio defined for radiographic grids?
Height of lead strips divided by distance between them
Number of lead lines per centimeter of grid
Thickness of lead strips times grid area
Angle of strips relative to central ray
Increasing grid ratio generally results in what imaging effect?
No change in scatter or contrast
Lower patient dose with same mAs
Better scatter cleanup and higher contrast
Worse scatter cleanup and lower contrast
What does grid frequency specify in a radiographic grid?
Number of lead lines per centimeter or inch
Ratio of strip height to strip spacing
Percentage of primary beam transmitted
Amount of scatter produced by tissue
How do focused grids differ from non-focused grids?
Focused grids eliminate the need for collimation
Focused grids are placed behind the image receptor
Focused grids have angled strips to match divergence
Focused grids use parallel strips for all beams
Where is a radiographic grid properly positioned during an exposure?
Between tube and patient
Directly on the X-ray tube housing
Between patient and image receptor
Behind the image receptor
Which factor most directly increases the quantity of x-ray photons produced in the tube?
Decreasing SID
Increasing mAs
Increasing filtration
Reducing kVp
What is the main effect of using a smaller focal spot size in radiography?
Decreases tube heat capacity
Increases image sharpness
Reduces beam intensity
Raises patient dose
Which adjustment will most effectively reduce patient exposure while maintaining image quality?
Reduce filtration
Increase kVp and decrease mAs
Decrease kVp and increase mAs
Increase OID
