All of the following are preferred cathode filament materials except:
copper
Determines how an unknown radiation will affect tissue by comparing with a reference radiation (250 kVp)
RBE
Which of the following cells are typically insensitive to radiation?
adult nerve cells
Free radicals behave as an extremely reactive single entity as a result of the presence of:
Unpaired electrons
ATP is an energy releasing phophate compound essential for sustaining life.
True
This transformer will raise voltage
step-up
If a magnet is brought near a piece of iron the iron nearest the magnet will assume the opposite polarity. This is called what?
induction
Filtration is expressed in the terms of
thickness of aluminum equivalency (Al/Eq)
Which rectified waveform has 3.5% ripple?
3 phase, 12 pulse
An example of high LET radiation is:
Alpha particle
To increase the time of an AEC exposure for a breathing technique adjust the:
mA selector
Cracking of the anode typically occurs:
when a cold anode is hit with a high kVp exposure.
Which of these units is not classified as a diagnostic unit? Chest Unit: Particle Accelerator:Radiographic and Fluroscopic: or C-arm
Particle Accelerator
An x-ray generator is the same as an electrical generator.
false
Radiolysis of water results in forming which of the following nasty molecules?1. hydroxyl radicals 2. hydroperoxyl radicals 3. hydrogen peroxide
1,2, and 3
Which of the following is a process of reduction cell division (i.e. reducing the # of chromosomes from 46 to 23)?
meiosis
The time required to respond to the radiation and terminate the exposure is called the:
backup time
The difference in electrical pressure between two points in a circuit is called what?
potential difference
A device that destroys itself to save other vital equipment is referred to as a:
fuse
In what order do the four stages of acute radiation syndrome present?
prodromal. manifest illness.latent period. recovery or death
Two unlike magnetic fields are arranged 10 cm apart. If the distance between them is reduced to 5cm
the force between them is now:, increase fourfold
Which timer uses a SCR circuit to control the exposure?
Electronic timer
Which suspension system is carefully counter-balanced to prevent tipping?
Floor
What reduces the line voltage to 6-12 volts and 3-5 amps.
step down transformer
According to data from studies performed on U.S. radiologic technologists individuals who began working before 1950 has a somewhat higher risk of dying from __________ when compared with technologists who started working in 1950 and later.
leukemia
A generator with only two segments on the commutator will produce what?
pulsating DC
An acceptable radiograph of the chest is taken using 6.4 mAs at 120 kVp at a distance of 72". The patient is not able to stand any longer and the x-ray must be repeated laying down. The new distance is 40". What mAs should be used to produce an acceptable
2 mAs
DNA that provides information controlling cell growth and metabolism is a:
nucleic acid
Which part of the x-ray circuit makes the voltage uniform?
line voltage compensator
This transformer uses electromagnetic self induction
autotransformer
Multiphase power is not the same as three-phase power.
false
6-pulse rectification produces a ripple of about 14%
3-phase generator
A typical x-ray tube might have a total inherent filtration of 0.5-1.0 mm Al/Eq.
True
What is the RMS voltage for an AC circuit with a peak voltage of 40 volts?
28
An example of a stochastic effect would be:
cancer
Which of the following is not a timer in an x-ray circuit? Mechanical Analog Electronic AEC
Analog
What is the resulting effect if you increase the anode angle?
increase the effective focal spot
Filtration is the process of eliminating undesirable low-energy x-ray photons by the insertion of absorbing materials into the primary beam.
True
Who discovered Ohm's law?
Ohm
How does electricity flow through a conductor?
Valance electrons jump from atom to atom
What do basal cells of the skin intestinal crypt cells, and reproductive cells have in common?
All are radiosensitive
It takes one volt to push through _____ ohm of resistance
one
What is controlled by a knob on the console?
autotransformer
120 pulses per second
single-phase generator
Which of the following cellular organells function as cellular garbage disposals?
lysosomes
Which timer uses a parallel plate ionization chamber?
AEC
A material can be magnetized if what?
the electrons of its atoms spin in one direction
How can we make something take on a negative static charge?
add electrons
Most diagnostic procedures result in equivalent doses:
less that 0.01 Sv (1 rem)
The most common filter material is
Aluminum
Cancer and genetic defects are examples of _______ effects.
stochastic
What is the power output of a single-phase generator that can produce 110 kV and 300 mA?
23,300 KW
Retentivity refers to what?
The ability of a magnet to resist demagnetization
Capacitor discharge units provide an RMS voltage significantly lower than the peak voltage.
True
step-up transformer and rectifier system can be made very small
high frequency generator
Tungsten is the metal of choice for the source of x-ray photons because of its:
high atomic number
Laminated transformer cores help to reduce power loss from eddy currents.
true
A rectifier changes:
AC to DC
Which of the following elements is not attracted by a magnet? iron copper nickel cobalt
Copper
Which statement is not correct? A. like charges repel unlike charges attract B. the charge is greatest on the most curved part of an oblong sphere C. the charge can exist on the interior part of a conductor D. only negative charges can move through a cond
C. the charge can exist on the interior part of a conductor
Radiation ionizes water which in turn interacts with the DNA molecule
indirect action
The rheostat is connected to the:
mA selector
requires 3 of everything auto-transformers, step-up windings, etc
3-phase generator
Melting of the anode commonly occurs:
when the stator fails and the rotor ceases to turn
According to U.S. Public Law 90-602 generators must terminate the exposure at 2,000 mAs above 50 kVp
false
maximum mA is always selected by the machine during the exposure-resulting in short exposures thus no breathing techniques
falling load generator
A high LET radiation is likely to cause ______ damage than a low LET radiation.
More
Which statement is a factor as to the size of induced EMF with electromagnetic induction between a wire and a magnetic field? speed of the conductor. angle between the conductor and flux lines.strenth of the magnetic field. all of the above. none of the a
all of the above
The zone of influence around the magnet is called:
magnetic field
This transformer will raise amperage
step-down
oxygen concentration will increase the likelihood of radiation damage
OER
How many types of electrical charges are there?
2
720 pulses per second
3-phase, 12 pulse generator
The idea that irradiation to a single key or master molecule controls the cell is referred to as:
Target theory
X-ray production requires all of the following to be present except a/an:
technologist
Water constitutes approximately _____ of the weight of the human body?
80%-85%
13,000 pulses per second
high frequency generator
Which of the following is the power rating equation for a three phase generator? W x V = A. W x A = V. A/V = W. V x A = W
V x A = W
Insulation of the high-voltage components of the tube and absorption of the heat produced by x-ray production is achieved through the use of:
dielectric oil
Which type of filtration is designed for unequal subject densities?
compensation
uses a chopper to produce output current of 500-5000 Hz
high frequency generator
What is the most common inorganic substance in the cell?
Water
6.24 x 10^18 electrons flowing past a point per second defines one
ampere
The mA controls the _____ of x-rays produced by the x-ray tube.
Quantity ( # of x-rays)
Mitosis is divided in 4 phases known as (select in the order they occur):
Prophase metaphase anaphase telophase
In 1988 after developing burns attributed to radiation exposure, this Boston dentist began investigating the hazards of radiation exposure and became the first advocate of radiation protection.
William Herbert Rollins
What is the power rating for single phase generator capable of delivering 99 kVp at 400 mA to the tube?
28,000 KW
Power loss due to the resistance in the wire of the coils is called hysteresis loss?
False
An x-ray exposure of 400 mR is recorded at a distance of 40". If the same technical factors are used what will the exposure be if the distance is increased to 72"?
123 mR
Which of the following uses the direct square law? filtration. mAs. kVp. distance
mAs
The "rotor" switch applies current to the stator.
true
What converts alternating current to direct current?
rectifier
Which of the following factors is the primary controller of radiographic film density and image receptor exposure (quantity)?
mAs
Work or power is measured in what unit?
watt
Electrons flow from negative (-) to positive (+) in circuits?
true
In a DNA macromolecule the sequence of _______ determines the characteristics of every living thing
Nitrogenous organic bases
Modern x-ray tubes use a metal envelope.
true
You should not plug many cords into one outlet because a fire may result when the total
amperage goes up
The exposure maintenance formula and the direct square law are the same.
True
The actual focal spot is controlled by the:
length of the filament
The timing circuit is connected to the:
time selector
What is the primary energy source of cells?
carbohydrates
Power to the high voltage side of the transformer comes from the:
Autotransformer
Point mutations typically occur with ______ LET radiation.
Low
This type of generator is typically used for dedicated chest units?
falling load generators
The filament current is measured in:
Amps
Like poles of magnets do what?
repel each other
To change the contrast of an AEC exposure, adjust the:
kV selector
All of the following are part of the primary circuit except:main switch. autotransformer. circuit breaker. rheostat
rheostat
Lines of force (flux) around a magnet move:
north to south
The area of the focal spot that is projected out of tube toward the object being radiographed is the:
effective focal spot
Which tabletop is the most common type?
flat
Which of the following will cause a decrease in resistance in a conductor?
increase in the cross-sectional area
This device is connected to the kVp selector on the control panel.
autotransformer
Which of the following is not a prime factor? filtration. mAs. kVp. distance
filtration
An acceptable radiograph of the humerus is produced using 8 mAs at 75 kVp. If the kVp is decreased by 15% to 64 kVp, what mAs would be needed to maintain the exposure?
16
Which generator provides the greates x-ray output?
3 phase, 12 pulse
The power loss in an electrical circuit may be defined by which equation?
PL=I2R
A thyratron is used in what type of timer?
phototimer
In which type of cell division does the nucleus divide first, followed by the cytoplasm?
Mitosis
Which phase produces 360 pulses per second?
Three phase
The filament voltage is measured in:
Volts
How is a voltmeter connected in a circuit?
in parallel
Lethal dose of ionizing radiation for humans is usually given as:
LD 50/60
Which of the following factors is the primary controller of contrast (quality)? filtration. mAs. kVp. distance
kVp
Opposition to the flow (resistance) of AC in a coil is referred to as what?
Inductance (back EMF)
12-pulse rectification produces ripple of about 4%
3 phase generator
An AC generator will not have what device?
commutator
A filament may break due to:
vaporization
All of the following units are specialized diagnostic equipment except: mammography. urologic. fluroscopic. tomography
fluroscopic
Which of the following is considered to be an insulator?
plastic
Which of the following occurs spontaneously in normal tissues or tumors?
Apoptosis
A thoerus filter is an example of this type of filtration?
compound
The primary factors are controlled by the generator?
false
When cells are exposed to sublethal doses of ionizing radiation approximately ______ of radiation induced damage may be reapaired over time, and about _______ is irreparable
90%, 10%
Somatic cells divide through the process of:
mitosis
What is the basic constituent of all matter?
carbon
When radiographing a wedge anatomical structure such as the femur the thicker portion of the anatomy should be positioned
under the cathode end of the tube
A function of the cathode is to produce:
a thermionic cloud
The modern minimum reaction time for AEC's is:
0.001 seconds
to determine power output of _______, wattage must be multiplied by .707
single phase generator
A "double strand break" is an example of interaction of energy with a:
DNA molecule
backup times may exceed the tube's heat limit.
false
The inverse square law is applied to the primary factor of distance.
True
mAs timers are used in falling load generators and capacitor discharge machines
true
360 pulses per second
three-phase, 6 pulse generator
Which of the following systems is the most radiosensitive vital organ system in human beings?
hematopoietic
The reciprocity law states that density/IR exposure will remain unchanged as long as the intensity and duration of the exposure are changed.
False
This machine takes incoming electricity and steps up and rectifies the high voltage to the x-ray tube. It also allows us to manipulate the current (mA) to determine quantity of x-rays.
X-ray generator
What is the power output of a 3-phase generator that can produce 100 kV at a maximum of 500 mA?
50,000 KW
The first coil in a transformer is called the primary coil.
True
X-ray equipment operates on an incoming line voltage of:
210-220 volts
Please list the syndromes in order as they relate to dose (low to high).
hematopoietic, gastrointestinal, cerebrovascular
Which type of filtration is a part of the structures of the tube and housing?
inherent
440 V is supplied to 1000 primary turns of an autotransformer. If the desired output voltage is 100 V how many secondary turns must be tapped?
227
The amount of energy delivered per unit of track by radiation
LET
220 volts are supplied to 800 primary turns of an autotransformer. What will be the output voltage across 400 secondary turns?
110
What automatic exposure control (AEC) device is connected to flurescent screens to produce a signal to the timer?
photomultiplier tube
An electron cloud (thermionic emission) is produced around the cathode inside the x-ray tube via:
Filament circuit
in order to take advantage of the anode heel effect it is best to position thicker parts under the
cathode
What device makes sure that the x-ray tube operates in a saturated state (maximum mA all the time)?
Space charge compensator
T/F: Special transformer coils are necessary for 3 phase circuits.
True
The exact point on the anode where the x-ray beam emanates is the:
focal spot
A device that allows the free flow of electrons is called what?
conductor
What tube-support system allows controls of longitudinal and transverse positioning as well as vertical distance?
Overhead suspension system
A cell will rupture when there is ______ water content.
too much
To change the density of an AEC exposure adjust the
density selector
Heating the filament to free electrons is called thermionic emission.
True
A stochastic effect is the same as:
Probablistic
Tilting tables are sometimes described by their tilting capabilities?
true
The law of Bergonie and Tribondeau states that "the radiosensitive of cells is _______ proportional to their reproductive activity and _______ proportional to their degree of differentiation".
directly/inversely
kV drops in relation to the selected mAs during exposure (not good)
capacitor discharge generator
Capacitors store electricity:
electrostatically
When filtration is increased technical factors are ________ to maintain the same image receptor exposure.
increased
pitting of the anode commonly occurs:
with extended use
What is total filtration?
sum of inherent and added
As more and more electrons build up in the area of the filament their negative charges oppose the emission of additional electrons. This phenomenon is known as:
space charge effect
What is the average (RMS) voltage if the peak voltage in a single-phase generator is 220?
155
It is acceptable to use compression bands as the sole restraint device.
false
The physical area of a rotating anode focal track affected by the cathode electron beam, is the
actual focal spot
The most common diagnostic radiography target angle is ________ degrees.
12
Back-up times should be set at ______ of the anticipated manual exposure mAs.
150%
Some examples of measurable late biologic damage are:1. Cataracts 2. Leukemia 3.nausea and vomitting 4. genetic mutations
1, 2, and 4 only
The focusing cup has a/an _________ charge.
negative
The protective housing controls leakage and scatter radiation through:
absorption
In the human cell protein synthesis occurs in which of the following locations?
ribosomes
What is the power output of a three-phase generator that can produce 150 kV and 500 mA?
75,000 KW
Who invented the bucky used in diagnostic x-ray equipment?
Dr. Bucky
Discharges a capacitor through the x-ray tube to create x-rays
capacitor discharge generator
________ are the energy warehouses and are most abundant in the ______ and _______.
Carbs, liver, muscle tissue
The electron flow between the cathode and the anode of the x-ray tube is called:
tube current
Which of the following is not an advantage to falling-load generators? Cannot be used for breathing techniques. Shorter times in heavy-load situations. Simpler operation. Less expensive
cannot be used for breathing techniques
Which of the following terms are similiar? I. electromitive force (EMF) II. Potential difference III. wattage
I and II
As the actual focal spot size increases the effective focal spot size:
increases.
All parts of the x-ray tube are located inside the glass envelope.
false
Is the same as the "quality factor" used to determine rems
RBE
Radiation acts on the DNA molecule
direct action
A macromolecule composed of amino acis that form 15% of cell content that include hormones enzymes, and antibodies are referred to as:
protiens
The autotransformer is connected to the:
kV selector
The power in a circuit equals
V x I
Mobile tube supports are the most costly and the most flexible.
False
A device that chemically produces potential difference is what?
Battery