Chapter 4 X-ray Circuit
A 12-volt battery use 12 joules of energy to move: 1 coulomb of charge 2 coulombs of charge 12 coulombs of charge 24 coulombs of charge
1 coulomb of charge
With self-induction, the secondary current: is in a secondary coil is in the original coil opposes the original current B and C
B and C
mAs is: another name for tube current related to the amount of radiation exposing the patient the product of mA and exposure time B and C
B and C
During a radiographic procedure using AEC, the exposure time will be shorter when the spine covers the ionization chamber, as compared with air covering the chamber. T/F
False
Every magnet has a north, south, east, and west pole. T/F
False
Lines of flux in the same direction attract each other. T/F
False
Nonmagnetic material, when interacting with a magnet, distorts the magnetic field. T/F
False
The autotransformer, using only one coil of wire, does not have both a primary and secondary side. T/F
False
The filament is a straight piece of wire in the cathode. T/F
False
The number of turns on the primary and secondary sides of the step-down transformer can be adjusted to control the current to the filaments. T/F
False
The synchronous timer is the most widely used timer in today's x-ray equipment. T/F
False
To produce x-rays, a cloud of electrons are necessary and the cathode must have a strong positive charge. T/F
False
The idea that electricity could be induced in a wire by moving it through a magnetic field was discovered by: Faraday Roentgen Telsa Oersted
Faraday
Place the following events leading to the production of x-rays in order from first to last: I. resistance is adjusted at the rheostat II. filament is heated III. filament current is increased IV. electrons are boiled off filalment
I, III, II, IV
Place the following events leading to the production of x-rays in order from first to last: I. electrons are boiled off the filament II. electricity leaves the autotransformer III. electricity goes to primary side of step-down transformer IV. filament is heated
II, III, IV, I
Place the following events leading to the production of x-rays in order, from first to last: I. kilovoltage is rectified II. voltage is adjusted at the autotransformer III. anode and cathode develop large positive and negative charges IV. voltage changes to kilovoltage IV, III, II, I II, IV, I, III III, I, II, IV I, II, IV, II
II, IV, I, III
Place the following events leading to the production of x-rays in order, from first to last: I. AC is converted to DC II. voltage is adjusted at the autotransfomer III. kilovoltage leaves the step-up transformer IV. voltage goes to primary side of step-up transformer I, II, III, IV, II, I, IV, III IV, III, II, I II, IV, III, I
II, IV, III, I
The primary side of the high-voltage transformer is found on the: primary circuit secondary circuit filament circuit none of the above
Primary circuit
Self-induction is based on the concepts introduced in: Ohm's law Lenz's law Oersted's law Faraday's law
Lenz's law
The idea that electricity flowing through a conductor produces a magnetic field was identified by: Faraday Roentgen Telsa Oersted
Oersted
Lines of flux in the opposite directions attract each other. T/F
True
Only electrons are free to move in solid conductors. T/F
True
Water with mineral impurities is a good conductor. T/F
True
With alternating current, the north and south poles of the magnetic field surrounding the wire change each time the electrons change direction. T/F
True
An electromagnet includes: a coil of wire an iron core a solenoid all of the above
all of the above
Half-wave rectification: suppresses half of the AC cycle uses two rectifiers is seldom used in modern x-ray equipment all of the above
all of the above
_____________ current is induced in the secondary coil when mutual induction takes place. Alternating direct neither A or B both A and B
alternating
60 Hz characterizes: alternating current indirect current direct current weak current
alternating current
Current that changes direction in the conductor is: alternating current indirect current direct current weak current
alternating current
With mutual induction, to induce voltage in the secondary coil, there must be: a physical connection between two coils of wire alternating current in the primary coil of wire direct current in the primary coil of wire A and B
alternating current in the primary coil of wire
Rubber is: an excellent conductor an excellent insulator a weak conductor a weak insulator
an excellent insulator
Electrification by induction requires that the two objects: are in direct constant contact with each other are not at all in contact with each other contact each other and then separate are as far apart as possible from each other
are not at all in contact with each other
If a conductor is curved, the greatest amount of charge will be found: at the beginning of the conductor at the end of the conductor at the area of the greatest curvature of the conductor along the straightest area of the conductor
at the area of the greatest curvature of the conductor
AEC stands for: automatic x-ray control applied exposure control automatic exposure control automatic exposure centering
automatic exposure control
The device referred to as the kVp selector is the: primary side of the high-voltage transformer secondary side of the high-voltage transformer step-down transformer autotransformer
autotransformer
The line compensator is typically wired to the: timer circuit primary side of the high-voltage transformer autotransformer step-down transformer
autotransformer
The only adjustable transformer in the x-ray circuit is the: Primary side of the high-voltage transformer secondary side of the high-transformer autotransformer step-down transformer
autotransformer
the device that produces electrons through a chemical reaction is a: transformer fuse resistor battery
battery
The purpose of the filament circuit is to: produce high voltage provide direct current to the x-ray tube boil electrons off the filament reduce the current reaching the filament
boil electrons off the filament
AEC controls the______________of radiation reaching the image receptor type quantity energy level all of the above
quantity
The device that change alternating to direct current are the: transformers filaments rectifiers rheostats
rectifiers
Slowing down the speed at which the conductor passes through the magnetic field results in: increased electromagnetic induction reduced electromagnetic induction no effect on electromagnetic induction
reduced electromagnetic induction
Reducing the number of coils in the wire will result in: Increased electromagnetic induction reduced electromagnetic induction no effect on electromagnetic induction
reducing electromagnetic induction
Like poles of a magnet _______ each other and opposite poles ________ each other. attract; attract repel; repel attract; repel repel; attract
repel; attract
One of the laws of electrostatics is that like charges _______ and unlike charges _______. attract; repel attract; attract repel; attract repel; repel
repel; attract
The property of a circuit that impedes the flow of electrons is: electric current electric potential resistance electrostatics
resistance
When a metallic conductor is colder: resistance decreases resistance increases resistance remains the same none of the above
resistance decreases
When a conductor has a smaller cross-sectional area: resistance decreases resistance increases resistance remains the same none of the above
resistance increases
When a conductor is longer: resistance decreases resistance increases resistance remains the same none of the above
resistance increases
When a conductor is more twisted: resistance decreases resistance increases resistance remains the same none of the above
resistance remains the same
Adjusting the rheostat changes the___________ in the _______ circuit. resistance; primary voltage; primary resistance; filament voltage; filament
resistance; filament
The device that regulates the amount of current flowing in the circuit is the: battery resistor fuse transformer
resistor
An adjustable form of a resistor is the: rheostat capacitor switch diode
rheostat
What must be adjusted to change the temperature of the filament? step-up transformer rheostat autotransformer solid-state rectifier
rheostat
The mA meter is found on the: primary circuit secondary circuit filament circuit none of the above
secondary circuit
The rectifiers are found on the: primary circuit secondary circuit filament circuit none of the above
secondary circuit
The secondary side of the high-voltage transformer is found on the: primary circuit secondary circuit filament circuit none of the above
secondary circuit
The x-ray tube (not filaments) is found on the: primary circuit secondary circuit filament circuit none of the above
secondary circuit
Mutual induction involves electricity being induced into a __________. primary coil secondary coil moving magnetic field none of the above
secondary coil
Determining which filament will be used during an exposure is done at the operating console by the selection of: small or large focal spot small or large filament high or low exposure time high or low kVp
small or large focal spot
Inside the magnet, the lines of flux travel from: north pole to south pole south pole to north pole east pole to west pole west pole to east pole
south pole to north pole
The _________________converts volts to kilovolts. step-down transformer step-up transformer autotransformer none of the above
step-up transformer
The timer that is based on a motor is the: synchronous timer mAs timer digital timer electronic timer
synchronous timer
Magnetic field strength is measured in: telsa ohms newtons joules
telsa
Assuming all other factors are accurately adjusted, the exposure time with AEC is based on: the procedure being done the anatomy placed over the ionization chamber the age of the patient the desired quality of the image
the anatomy placed over the ionization chamber
A pulsed DC is produced by: half-wave rectification full-wave rectification three-phase power high-frequency generators
high-frequency generators
The least amount of ripple is the result of: half-wave rectification full-wave rectification three-phase power high-frequency generators
high-frequency generators
The primary purpose of the step-down transformer is to: decrease the voltage going to the filaments decrease the amperage going to the filaments increase the amperage going to the filaments
increase the amperage going to the filaments
Increasing the strength of the magnetic field results in: increased electromagnetic induction reduced electromagnetic induction no effect on electromagnetic induction
increased electromagnetic induction
A step-up transformer results in: increased current increased voltage A and B none of the above
increased voltage
When there is movement of some of the electrons of an uncharged metallic object as it is brought into the electric field of a charged object, this is electrification by: contact friction induction A and B
induction
A material that resists the movement of electrons is a(n): ohm insulator conductor inductor
insulator
Glass is an example of a(n): insulator conductor material that allows the flow of electrons inductor
insulator
The force of magnetic attraction varies: directly with the square of the strength of the poles inversely with the square of the strength of the poles directly with the square of the distance between the poles inversely with the square of the distance between the poles
inversely with the square of the distance between the poles
A transformer with 100 turns on the primary side and 50 turns on the secondary: is a step-up transformer is a step-down transformer is a transformer that works on self-induction will have 100 times the current on the secondary side
is a step-down transformer
A transformer with 100 times more turns on the secondary side as compared with the primary: is a step-up transformer is a step-down transformer is a transformer that works on self-induction will have 100 times the current on the secondary side
is a step-up transformer
As 2 charges get closer, the electrostatic force: is directly proportional to the amount of distance between them is inversely proportional to the amount of distance between them is inversely proportional to the square of the distance between them is directly proportional to the square of the distance between them
is inversely proportional to the square of the distance between them
A volt is the ratio of work per unit of charge and is written: joules/coulomb coulomb/joules watt/coulomb coulomb/watt
joules/coulomb
Kilovolt peak is abbreviated as: KP kPk kVPk kVp
kVp
The device the adjusts the incoming power supplied to the x-ray circuit to maintain 220 V is the: circuit breaker autotransformer timer circuit line compensator
line compensator
The lines of force in space associated with a magnet are called: lines of flux dipoles domains lines of field
lines of flux
The selection of the large or small filament in the cathode depends on the choice of focal spot size at the operating console and the: exposure time selected kVp selected mA station selected all of the above
mA station selected
The timer located on the secondary circuit is the: synchronous timer mAs timer digital timer none of the above
mAs timer
The ability of a material to attract iron, cobalt, or nickel is called: electromagnetism potential difference magnetism voltage
magnetism
A device that converts electrical energy to mechanical energy is a: motor transformer generator electromagnet
motor
The purpose of grounding is to: provide a source for electricity neutralize a charged object replace the circuit breaker none of the above
neutralize a charged object
Closed-core and shell-type transformers: are seldom used in x-ray equipment are less efficient types of transformers are simpler types of transformers none of the above
none of the above
Wood and plastic are considered: nonmagnetic paramagnetic ferromagnetic diamagnetic
nonmagnetic
Outside the magnet, the lines of flux travel from: north pole to south pole south pole to north pole east pole to west pole west pole to east pole
north pole to south pole
A(n) ________ is the electrical resistance between two points along a conductor that, when one volt is applied, produces 1 ampere of current. amp volt ohm watt
ohm
A device that temporarily stores charge is the: rheostat capacitor transformer fuse
capacitor
A material that allows electrons to move is a(n): volt insulator conductor inductor
conductor
Which of the following materials is a good conductor? glass copper plastic they are all good conductors
copper
The unit of measurement of electrical charges (SI) is: watt joule newton coulomb
coulomb
When a negative charge is placed on the p-type crystal and a positive charge on the n-type crystal, the result is: current flows the diode current does not flow through the diode voltage decreases voltage increases
current does not flow through the diode
Which of the following occurs first in the sequence of events leading to x-ray production? voltage is stepped down and amperage increases electron cloud is produced current is adjusted by rheostat electrons flow from cathode to anode
current is adjusted by rheostat
The solid-state rectifier has a(n)__________ crystal and a(n)__________ crystal. a-type; b-type x-type; z-type a-type; c-type p-type; n-type
p-type; n-type
A material that is weakly attracted to a magnetic field is: nonmagnetic paramagnetic ferromagnetic diamagnetic
paramagnetic
For AEC, the ionization chamber is placed between the _________ and _______. tube; patient patient; image receptor grid; image receptor image receptor; wall
patient; image receptor
A step-up transformer results in: decreased current decreased voltage A and B none of the above
decreased current
A step-down transformer results in: decreased current decreased voltage A and B none of the above
decreased voltage
The autotransformer is found on the: primary circuit secondary circuit filament circuit none of the above
primary circuit
The main power switch is found on the: primary circuit secondary circuit filament circuit none of the above
primary circuit
The timer circuit is found on the: primary circuit secondary circuit filament circuit none of the above
primary circuit
A material that is weakly REPELLED by a magnetic field is classified as: nonmagnetic paramagnetic ferromagnetic diamagnetic
diamagnetic
Which of the following devices allow the electricity to flow in one direction only? fuse switch transformer diode
diode
A battery produces: alternating current indirect current direct current current that changes direction
direct current
A closed pathway of wires and related elements is a(n): diode fuse rheostat electric circuit
electric circuit
The ampere is the unit of measure for: electric current electric potential resistance electrostatics
electric current
The flow of electrons along a conductor is: electric current electric potential resistance electrostatics
electric current
The ability to do work because of a separation of charges is electric current electric potential resistance electrostatics
electric potential
The volt is the unit of measure for: electric current electric potential resistance electrostatics
electric potential
Electricity is typically thought to be: electromagnetism electrodynamics electronics electrostatics
electrodynamics
The study of electric charges in motion is electrodynamics electromagnetism electronics electrostatics
electrodynamics
One coulomb is equal to the electrical charge of 6.25 X 10^18 electrons protons neutrons nuclei
electrons
The n-type crystal from a solid-state rectifier has an abundance of: electrons electron traps protons proton traps
electrons
A material that is strongly attracted to a magnetic field is: nonmagnetic paramagnetic ferromagnetic diamagnetic
ferromagnetic
The filament within the x-ray tube are found on the: primary circuit secondary circuit filament circuit none of the above
filament circuit
The rheostat is found on the: primary circuit secondary circuit filament circuit none of the above
filament circuit
The step-down transformer is found on the: primary circuit secondary circuit filament circuit none of the above
filament circuit
Rubbing a rubber rod with fur is an example of electrification by: contact friction induction A and B
friction
Four rectifiers will produce: alternating current half-wave rectified current full-wave rectified current indirect current
full-wave rectified current
A device that converts mechanical energy to electrical energy is a: motor transformer generator electromagnet
generator
which of the following is NOT a good electrical conductor? gold copper glass water
glass
Which of the following is NOT a good insulator? glass gold wood ceramic
gold
A general purpose radiographic tube typically has_________ filament(s). one two three four
two
The autotransformer: uses self-induction uses two coils of wire does not use a magnetic core is not typically found in an x-ray machine
uses self-induction
Three-phase power: uses three AC waveforms at the same time results in three times the ripple is half-wave rectified A and B
uses three AC waveforms at the same time
Which of the following occurs first in the sequence of events leading to x-ray production? AC is converted to DC voltage becomes kilovoltage anode and cathode become positively & negatively charged electrons flow from cathode to anode
voltage becomes kilovoltage
Ohm's Law can be written as: amps= volts X ohms volts= amps X ohms ohms= volts X amps none of the above
volts= amps X ohms
Single-phase full-wave rectified current has: 10% ripple 25% ripple 50% ripple 100% ripple
100% ripple
the rate of flow of electrons passing through the x-ray tube during an exposure is: mA tube current filament current A and B
A and B
To get electrons to flow along a conductor, there must be: an excess of negative charges at one end of the wire an excess of negative charges at both ends of the wire an excess of positive charges at one end of the wire an excess of positive charges at both ends of the wire A and C
A and C
Three-phase power has less than 1% ripple. T/F
False
A capacitor and rheostat are used in electronic timers. T/F
True
Electric charges are found only on the outside of a conductor. T/F
True
A step-down transformer results in: increased current increased voltage A and B none of the above
increased current
When a switch is turned on, the electric circuit: is closed does not allow electrons to flow is opened none of the above
is closed
Which of the following devices can increase or decrease voltage by a set amount? battery capacitor transformer A and C
transformer
A volt is the potential difference that will maintain a current of ________ ampere in a circuit with a resistance of ______ ohm. 1; 2 2; 1 1; 1 2; 2
1; 1
The ampere is defined as ________ coulomb passing by a point in ______second. 1; 1 2; 1 1; 2 2; 2
1; 1
Which of the following requires the greatest amount of resistance in the filament circuit (assuming the voltage is the same for each)? 50 mA 100 mA 600 mA 1000 mA
50 mA
How much current is needed to heat the filament enough to produce a 100 to 1000 mA tube current? 1 A to 10 A 5 A to 7 A 1 mA to 10 mA 5 mA to 7 mA
5 A to 7 A
Which of the following opens a circuit to keep the circuit and devices safe? fuse resistor circuit breaker A and C
A and C
Ohm's Law can be written as: I = V/R I = R/V R = I/V R = IR
I = V/R
Ripple refers to: the fluctuation in amperage in the electricity the fluctuation in voltage in the electricity the fluctuation in resistance in the electricity all of the above
the fluctuation in voltage in electricity
The less ripple: the more consistent the energy of the x-rays produced the less consistent the energy of the x-rays produced the greater the amount of radiation needed for a specific exposure none of the above
the more consistent the energy of the x-rays produced
