Rad Physics Final Flashcards
What is the smallest particle of an element that retains the characteristics of the element?
A. Mole
B. Atom
C. Molecule
D. Quark
B. Atom
X-rays travel as bundles of energy called:
A. Energy waves
B. Phasers
C. Electromagnetic bursts
D. Photons
D. Photons
What type of current is required for proper operation of the x-ray tube?
A. Direct
B. Falling load
C. Alternating
D. Fluctuating
A. Direct
The law stating that the outer shell of an atom can contain no more than eight electrons is called:
A. Ohm’s law
B. Octet rule
C. Octagon rule
D. Electron binding energy
B. Octet rule
Electromagnetic radiation travels:
A. In waves along a straight path
B. In circles
C. Back and forth
D. As electrons in waves along a straight path
A. In waves along a straight path
At what speed do x-rays travel?
A. The speed of light – 186,000 miles per hour
B. The speed of incident electrons – 93,000 miles per second
C. The speed of light – 186,000 miles per second
D. Infinite speed
C. The speed of light – 186,000 miles per second
Waves of radiation are called:
A. Sine waves
B. Strong waves
C. Signal waves
D. Current waves
A. Sine waves
Wavelength is defined as:
A. The x-ray tube to the patient
B. The cathode to the anode
C. The bottom of a wave to the top
D. Peak to peak of the wave
D. Peak to peak of the wave
Frequency is defined as:
A. Synonymous with wavelength
B. The number of waves passing a point per unit time
C. The number of waves striking the patient
D. The number of exposures needing during an exam
B. The number of waves passing a point per unit time
The speed of x-rays is based on:
A. mAs
B. kVp
C. The size of the patient
D. The fact that they are a form of electromagnetic radiation
D. The fact that they are a form of electromagnetic radiation
Wavelength and frequency are:
A. Directly proportional to each other
B. Inversely proportional to each other
C. Inversely proportional to the square of their distance
D. Unrelated to each other
B. Inversely proportional to each other
The x-ray beam changes as it travels through the patient by a process called:
A. Filtration
B. Attenuation
C. Electrification
D. Annihilation
B. Attenuation
The intensity of radiation is inversely proportional to the square of the distance between the source of radiation and the person receiving it. This describes the:
A. Square law
B. Reciprocity law
C. Inverse square law
D. Octet law
C. Inverse square law
The two types of electromagnetic radiation are:
A. Autoinduction and mutual induction
B. Self-induction and mutual induction
C. Generated induction and self-induction
D. Current induction and voltage induction
B. Self-induction and mutual induction
Self-induction is used in the operation of what device?
A. Step-up transformer
B. Autotransformer
C. Step-down transformer
D. Electronic timer
B. Autotransformer
The strength of the magnetic fields in a transformer is increased by:
A. Coiling the wires and placing them in adjoining machines
B. Coiling the wires and letting their magnetic fields overlap
C. Keeping the wires very straight, increasing their effectiveness
D. Replacing the wires with diodes
B. Coiling the wires and letting their magnetic fields overlap
Electricity is supplied to the imaging department by a:
A. Motor
B. Rectifier
C. Generator
D. Voltmeter
C. Generator
High-frequency power:
A. Is less effective than single-phase power
B. Has almost no ripple
C. Has more ripple than three-phase power
D. Is yet unproved
B. Has almost no ripple
A variable transformer that is used to select kV for the x-ray circuit is the:
A. Step-up transformer
B. Autotransformer
C. Step-down transformer
D. Rectifier
B. Autotransformer
A transformer that has more turns in the secondary coil than in the primary coil is called a:
A. Step-up transformer
B. Solenoid
C. Step-down transformer
D. Filament transformer
A. Step-up transformer
What is the transformer used to boost voltage to kilovoltage called?
A. Autotransformer
B. Step-down transformer
C. Step-up transformer
D. Low-voltage transformer
C. Step-up transformer
Voltage coming to the x-ray machine is kept constant through the use of a(n):
A. Autotransformer
B. Step-down transformer
C. Rectifier
D. Line voltage compensator
D. Line voltage compensator
A step-down transformer:
A. Steps down voltage
B. Steps down current
C. Steps up voltage
D. Steps up resistance
A. Steps down voltage
Where does thermionic emission occur?
A. Step-down transformer
B. Rectifier
C. Cathode
D. Timer
C. Cathode
Which of the following devices is prereading?
A. Step-down transformer
B. Rectifier
C. Timer
D. kVp meter
D. kVp meter
Which device reduces voltage and provides current to produce an electron cloud or space charge at the filament?
A. Step-down transformer
B. Rectifier
C. Cathode
D. Timer
A. Step-down transformer
Which device is electronic, with a setting as low as 0.001?
A. Step-down transformer
B. Rectifier
C. Cathode
D. Timer
D. Timer
What changes AC to DC?
A. Step-down transformer
B. Rectifier
C. Cathode
D. Timer
B. Rectifier
Which of the following is surrounded by a negatively charged focusing cup?
A. Step-down transformer
B. Rectifier
C. Filament
D. Timer
C. Filament
Which of the following is composed of solid-state silicon-based diodes?
A. Step-down transformer
B. Rectifier
C. Cathode
D. Timer
B. Rectifier
What regulates the duration of x-ray production?
A. Step-down transformer
B. Rectifier
C. Cathode
D. Timer
D. Timer
What is located in the x-ray circuit between the high-voltage transformer and the x-ray tube? A. Step-down transformer
B. Rectifier
C. Cathode
D. Timer
B. Rectifier
Which of the following measures tube current?
A. Anode
B. mA meter
C. Ionization chamber
D. Step-up transformer
B. mA meter
What device spins at 10,000-12,000 rpm?
A. Anode
B. mA meter
C. Ionization chamber
D. Falling load generator
A. Anode
What is the source of Bremsstrahlung and characteristic x-rays?
A. Anode
B. mA meter
C. Falling load generator
D. Step-up transformer
D. Step-up transformer
What is the most commonly used AEC?
A. Phototimer
B. mA meter
C. Ionization chamber
D. Falling load generator
C. Ionization chamber
What device is turned by a rotor?
A. Anode
B. mA meter
C. Ionization chamber
D. Step-up transformer
A. Anode
The filament is kept warm by:
A. A standby current from the time the x-ray machine is turned on
B. Insulating oil
C. Lead housing
D. A current produced only during exposures
A. A standby current from the time the x-ray machine is turned on
Activating the rotor:
A. Accelerates a procedure
B. Reduces tube life
C. Keeps it oiled
D. Keeps the cooling fan activated
B. Reduces tube life
When making an exposure, the radiographer should:
A. Hold the rotor for several seconds before pressing “expose”
B. Activate the rotor and exposure switch in one continuous motion
C. Begin the rotor while a student is still positioning a patient
D. Activate the rotor while estimating how fast the anode is spinning
B. Activate the rotor and exposure switch in one continuous motion
The process of thermionic emission causes:
A. Electrons to boil off the anode
B. The anode to spin
C. The cathode to cool quickly
D. Electrons to boil off the filament
D. Electrons to boil off the filament
The force with which the electron stream passes from the cathode to the anode is a result of ____ passing through the x-ray tube
A. Current
B. Kilovoltage
C. Tungsten
D. Heat
B. Kilovoltage
Heat is produced in the x-ray tube as:
A. Electrons break apart while striking the anode
B. Electrons interact with the target material
C. The anode stops spinning
D. The rectifier operates
B. Electrons interact with the target material
Most of the energy conversion in the x-ray tube produces:
A. X-rays
B. Light
C. Heat
D. Current
C. Heat
X-rays are produced as incident electrons are slowed going past the nuclei of target atoms by a process called:
A. Classical
B. Photoelectric
C. Bremsstrahlung
D. Compton
C. Bremsstrahlung
X-rays are produced as incident electrons collide with inner shell electrons in target atoms by a process called:
A. Characteristic
B. Photoelectric
C. Bremsstrahlung
D. Compton
A. Characteristic
What percentage of energy in the x-ray tube is converted to x-rays?
A. 99%
B. 75%
C. 1%
D. 100%
C. 1%
Which of the following are properties of x-rays? (Select 5)
a. Electrically negative
b. Scatter and produce secondary radiation
c. Invisible to the human eye
d. Travel at the speed of light (186,000 miles per hour)
e. Possess wavelengths between 1 A and 5 A
f. Travel in bundles of energy called photons
g. Can ionize matter and gasses
h. Can be focused by collimators
i. Cause phosphors to fluoresce
b. Scatter and produce secondary radiation
c. Invisible to the human eye
f. Travel in bundles of energy called photons
g. Can ionize matter and gasses
i. Cause phosphors to fluoresce
The x-ray beam is:
A. Heterogenous–all rays possess the same energy
B. Homogenous–all rays produce the same energy
C. Monoenergetic–all energies correspond to the kVp
D. Heterogenous or polyenergetic–consist of many different energies (wavelengths)
D. Heterogenous or polyenergetic–consist of many different energies (wavelengths)
The x-ray emission spectrum consists of:
A. Brems and characteristic rays
B. Discrete spectrum (produced by brems rays) and continuous spectrum (produced by characteristic rays)
C. Discrete spectrum (produced by characteristic rays) and continuous spectrum (produced by brems rays)
D. X-rays and electrons, both part of the electromagnetic spectrum
C. Discrete spectrum (produced by characteristic rays) and continuous spectrum (produced by brems rays)
The primary purpose of filtration is:
A. Radiation protection
B. To remove short-wavelength (soft) rays
C. To harden the beam for imaging
D. To remove long-wavelength (hard) rays
A. Radiation protection
Which of the following statements regarding filtration is true?
A. Total filtration must not be less than 2–mm aluminum equivalent
B. Total filtration must remove all soft rays from the beam
C. Total filtration (added + compensating) must not be less than 2.5-mm aluminum equivalent
D. Total filtration (not less than 2.5-mm aluminum equivalent) = inherent filtration (glass envelope, tube housing oil) + added filtration (aluminum)
D. Total filtration (not less than 2.5-mm aluminum equivalent) = inherent filtration (glass envelope, tube housing oil) + added filtration (aluminum)
The primary type of grid used in diagnostic imaging is:
A. Crosshatch
B. Parallel
C. Rhombic
D. Focused
D. Focused
Single-phase, full-wave rectification produces:
A. Direct current
B. Pulsating direct current
C. Pulsating direct current with 120 pulses per second
D. Pulsating direct current with 120 pulses per second and 100% ripple
D. Pulsating direct current with 120 pulses per second and 100% ripple
Three-phase, 6-pulse full-wave rectification produces:
A. Direct current with 13-14% ripple
B. Direct current with 4% ripple
C. Direct current with 100% ripple
D. Alternating current with 13% ripple
A. Direct current with 13-14% ripple
Three-phase, 12-pulse full-wave rectification produces
A. Direct current with 13-14% ripple
B. Direct current with 4% ripple
C. Direct current with 100% ripple
D. Alternating current with 13% ripple
B. Direct current with 4% ripple
The radiographic image is formed by:
A. Exit rays striking the image receptor
B. Laser light
C. Cosmic rays
D. Electrons and heat
A. Exit rays striking the image receptor
The primary controlling factors of receptor exposure are:
A. kVp and mAs
B. mAs and SID
C. SID and OID
D. SID, OID, and FSS
A. kVp and mAs
Which of the following describes the relationship between mAs and receptor exposure?
A. Receptor exposure is directly proportional to mAs
B. Receptor exposure is inversely proportional to mAs
C. Receptor exposure is directly proportional to mAs^2
D. mAs controls the number of electrons boiled off the anode and the number of x-rays produced
A. Receptor exposure is directly proportional to mAs
The number of electrons boiled off the cathode and consequently the number of x-rays produced are controlled by:
A. kVp
B. SID
C. mA
D. OID
C. mA
Receptor exposure was formerly called:
A. Contrast
B. Detail
C. Density
D. Distortion
C. Density
mAs directly controls:
A. The energy of the x-ray emission spectrum
B. The quality and quantity of x-rays produced at the cathode
C. The quality and quantity of x-rays produced at the anode
D. The quantity of x-rays produced at the anode
D. The quantity of x-rays produced at the anode
The relationship between kVp and receptor exposure may be described as:
A. Directly proportional
B. Direct, although not proportional
C. Governed by the 15 to 50 rule
D. Controlled by the x-ray tube current
B. Direct, although not proportional
The 15% rule states that:
A. Receptor exposure may be halved by decreasing the kVp by 15%
B. kVp should be 15% of the mAs selected
C. Receptor exposure may be halved by increasing kVp by 15%
D. At least a 15% change in mAs is required to make a change visible
C. Receptor exposure may be halved by increasing kVp by 15%
Which of the following governs the relationship between SID and receptor exposure?
A. Reciprocity law
B. 15% rule
C. Inverse square law
D. Ohm’s law
C. Inverse square law
Which of the following describes the relationship between receptor exposure and the use of grids?
A. Grids always reduce receptor exposure
B. Grids reduce receptor exposure unless mAs is increased to compensate
C. Grids reduce receptor exposure by only absorbing scatter radiation
D. Receptor exposure increases as grid ratio increases
B. Grids reduce receptor exposure unless mAs is increased to compensate
The use of filtration:
A. Greatly reduces receptor exposure because of the absorption of short-wavelength x-rays
B. Greatly reduces radiographic receptor exposure because of the absorption of high-energy x-rays
C. Increases radiographic receptor exposure by removing long-wavelength x-rays
D. Has little effect on receptor exposure because x-rays removed from the beam are not image-producing rays
D. Has little effect on receptor exposure because x-rays removed from the beam are not image-producing rays
As beam restriction increases (becomes tighter):
A. Receptor exposure increases
B. Receptor exposure increases as a result of focusing of x-rays
C. Receptor exposure decreases
D. Receptor exposure is not affected
C. Receptor exposure decreases
Which of the following affects receptor exposure?
A. Atomic mass of the x-ray anode
B. X-ray tube angle
C. Atomic number of the cathode filament
B. X-ray tube angle
The variation of x-ray beam intensity along the longitudinal axis of the x-ray beam describes:
A. Beam collimation
B. Positive beam limitation
C. Anode heel effect
D. X-ray emission spectrum
C. Anode heel effect
The thicker part of the anatomy should be placed under which aspect of the x-ray tube?
A. Central ray
B. Cathode
C. Anode
D. Collimator
B. Cathode
The function of contrast is to:
A. Make the image appear sharper
B. Compensate for uneven anatomic structures
C. Brighten the image
D. Make details visible
D. Make details visible
A radiographic image with few gray tones, primarily exhibiting black and white, would be described as having what type of contrast? (Select 2)
A. Long scale
B. Short scale
C. Low
D. High
B. Short scale
D. High
Lower spatial resolution may be caused by which of the following factors?
A. Short OID
B. Long SID
C. Small focal spot
D. Wide pixel pitch
D. Wide pixel pitch
Which of the following describes the outcome of using high kVp? (Select 3)
A. High contrast
B. Few gray tones
C. Long-scale contrast
D. Short-scale contrast
E. Low contrast
F. Many gray tones
C. Long-scale contrast
E. Low contrast
F. Many gray tones
Which of the following describes the outcome of using low kVp? (Select 3)
A. High contrast
B. Few gray tones
C. Long-scale contrast
D. Short-scale contrast
E. Low contrast
F. Many gray tones
A. High contrast
B. Few gray tones
D. Short-scale contrast
More uniform penetration of anatomic structures occurs when what level of kVp is used?
A. Low
B. High
C. kVp does not affect penetration
D. The level at which photoelectric interaction predominates
B. High
Differential absorption of the x-ray beam is a function of:
A. Compton interaction
B. Atomic mass of anatomic structures
C. mAs
D. Photoelectric interaction
D. Photoelectric interaction
What affect does beam restriction have on contrast
A. Decreases contrast by focusing the x-ray beam
B. Decreases contrast because a higher kVp level is used
C. Increases contrast by focusing the x-ray beam
D. Increases contrast because of reduction in the number of Compton interactions that occur
D. Increases contrast because of reduction in the number of Compton interactions that occur
The adjustment in technical factors required when using beam restriction is to:
A. Increase kVp
B. Decrease kVp to reduce the number of Compton interactions taking place
C. Decrease mAs to compensate for the number of rays removed from the primary beam
D. Increase mAs to compensate for the number of rays removed from the primary beam
D. Increase mAs to compensate for the number of rays removed from the primary beam
What effect does the use of radiographic grids have on contrast?
A. Decreases contrast
B. Increases contrast
C. No effect on contrast
D. Increases contrast by absorbing scatter radiation
D. Increases contrast by absorbing scatter radiation
As the amount of beam filtration is increased:
A. Contrast increases
B. There is no effect on contrast
C. Contrast decreases
D. Contrast increases because the beam is harder
C. Contrast decreases
The portion of contrast that is caused by variations in the anatomy or that is secondary to pathological changes is called:
A. Radiographic contrast
B. Anatomic contrast
C. Pathologic contrast
D. Subject contrast
D. Subject contrast
Spatial resolution is:
A. Photographic representation of the part being radiographed
B. Controlled by kVp
C. Controlled by mAs
D. Geometric representation of the part being radiographed
D. Geometric representation of the part being radiographed
Which of the following will result in higher spatial resolution? (Select 3)
A. Long SID
B. Long OID
C. Short SID
D. Short OID
E. Large focal spot
F. Small focal spot
A. Long SID
D. Short OID
F. Small focal spot
Optimal spatial resolution may be created using which of the following factors?
A. Large focal spot
B. Narrow pixel pitch
C. Long OID
D. Short SID
B. Narrow pixel pitch
Improper use of grids may result in an image artifact known as:
A. SNR
B. Moire pattern
C. Elongation
D. Foreshortening
B. Moire pattern
Distortion may be described as:
A. Misrepresentation of an anatomic structure on the image
B. Foreshortening
C. Elongation
D. Magnification
A. Misrepresentation of an anatomic structure on the image
Elongation and foreshortening are examples of:
A. Size distortion
B. Shape distortion
C. Motion
D. Distortion caused by short SID and long OID
B. Shape distortion
Magnification is caused by: (Select 2)
A. Short SID
B. Long SID
C. Short OID
D. Long OID
A. Short SID
D. Long OID
Distortion that occurs when the x-ray beam is angled along the long axis of a part is:
A. Elongation
B. Magnification
C. Minification
D. Misrepresentation
A. Elongation
Gross overexposure of the IR results in:
A. Saturation
B. Oversampling
C. Extreme latitude
D. High spatial resolution
A. Saturation
Quantum noise limits ability to see:
A. Detail
B. Contrast
C. Fatty tissue
D. Additive pathologies
A. Detail
Grid ratio is defined as:
A. The ratio of the lead strips to the space between them
B. The thickness of the lead strips divided by the thickness of the aluminum interspacers
C. The ratio of the height of the lead strips over the distance between the lead strips
D. The ratio of the distance between the lead strips over the height of the lead strips
C. The ratio of the height of the lead strips over the distance between the lead strips
Which of the following are true concerning grids? (Select 3)
A. Contrast improvement factor is the measure of the ability of a grid to enhance contrast
B. Grid selectivity is the ratio of primary radiation transmitted through the grid to secondary radiation transmitted through the grid
C. Grids are used when part thickness is less than 10 cm
D. GCF is the amount of increase in kVp necessary when converting from nongrid to grid technique
E. The primary purpose of grids is radiation protection
F. The main function of grids is to prevent Compton scatter from reaching the IR
G. Grids prevent the production of scatter
A. Contrast improvement factor is the measure of the ability of a grid to enhance contrast
B. Grid selectivity is the ratio of primary radiation transmitted through the grid to secondary radiation transmitted through the grid
F. The main function of grids is to prevent Compton scatter from reaching the IR
A grid with lead strips and aluminum interspacers that are angled to coincide with the divergence of the x-ray beam is called a:
A. Parallel grid
B. Focused grid
C. Crosshatch grid
D. Rhombic grid
B. Focused grid
The range of SIDs that may be used with a focus grid is called:
A. Grid ratio
B. Objective plane
C. Anticutoff distances
D. Focal distance (grid radius)
D. Focal distance (grid radius)
The best scatter cleanup is achieved with the use of:
A. Air gap technique
B. Focused grids
C. Crosshatch grids
D. Parallel grids
C. Crosshatch grids
Grid cutoff may be described as:
A. Decreased density in the middle of the radiograph caused by using a parallel grid inserted upside down
B. Decreased density on a radiograph as a result of absorption of image-forming rays
C. Increased density in the center of a radiograph caused using a focused grid inserted upside down
D. Decreased density on the edges of a radiograph only
B. Decreased density on a radiograph as a result of absorption of image-forming rays
Use of the air gap technique:
A. Works because x-rays are absorbed in the air between the patient and the image receptor
B. Should occur when possible
C. May cause some magnification because of decreased OID
D. Works because scatter radiation travels in divergent paths and misses the IR as a result of increased OID
D. Works because scatter radiation travels in divergent paths and misses the IR as a result of increased OID
The number of pixels making up the digital image is the:
A. Pixel depth
B. Matrix size
C. Pixel pitch
D. Field of view
B. Matrix size
The smallest area represented in a digital image is the:
A. Image matrix
B. Pixel
C. Voxel
D. Bit
B. Pixel
The number of pixels/mm in an image is called:
A. Pixel density
B. Bit depth
C. Pixel pitch
D. Matrix depth
A. Pixel density
The space from the center of a pixel to the center of the adjacent pixel is called:
A. Pixel density
B. Bit depth
C. Pixel pitch
D. Matrix depth
C. Pixel pitch
Mathematical codes use to generate the digital image are called:
A. Binary codes
B. Algorithms
C. Binary digits
D. Bytes
B. Algorithms
