What purpose does a circuit breaker serve in an electric circuit?

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Question	Answer
Nonmetals make the best conductors.	False
Which of the following is a common insulator?	plastic
An open circuit will conduct electricity.	false
What purpose does a circuit breaker serve in an electric circuit?	Protect against circuit overload
An electrical device with a deficiency of electrons will do which of the following when grounded?	Take on electrons until neutral
Which of the following symbols momentarily stores electric charge?	---] [---
What charge will an atom with more protons than electrons have?	positive
The movement of which of the following is most often recognized as electricity?	Electrons
Which of the following will move in solid conductors?	negative charges
According to Coulomb’s Law, what will happen to the electrostatic force between two charges if the distance between them is cut in half?	Quadruples
When electrons are rubbed off one object and deposited to another, this is electrification by:	Friction
What happens to the electric potential as the electric field increases?	Increase
Which of the following are required for electric current to exist? 1. Electric potential difference. 2. Equal number of positive and negative charges. 3. Suitable medium in which to travel.	1 &3
The SI unit for charge or current flow per second is:	Ampere
If a given conductor is carrying a high voltage, what is the amperage?	Low
In which media will ions drift towards the oppositely charged electrode? 1. Vacuum 2. Gas 3. Ionic solution 4. Metallic conductor	2 and 3 only
The property of a conductor that hinders the flow of electricity is:	Resistance
Which of the following will have the greatest resistance?	Material with few free electrons/ high temperature.
An electric circuit has a current of 6 amperes and a resistance of 3 ohms. What is the current if you increase the total resistance in the circuit to 6 ohms? (Assume that the voltage is unchanged.)	3 ampere
A meter placed in the heating resistor circuit shows that 5A is flowing through the resistor. If the resistor is 20 Ω, what is the voltage across it?	100V
A 110 V heater requires 15 A. What is the power consumption?	1650W
An x-ray imaging system has a 30 kW generator. If the maximum tube voltage is 150 kV, what is the available tube current?	200mA
How many volts are required to move a current of 60 amperes across a circuit having a resistance of 2 ohms?	120 volts
A series circuit has resistors measuring 10, 15, 20 and 30 ohms with a current of 5 amps. What is the total voltage of the circuit?	375volts
Three resistors are connected in parallel to a battery of 18V, with resistances of 3 ohms, 6 ohms, and 9 ohms. What is the total resistance?	1.6ohms
What is the total current in the circuit connected in parallel to a battery of 18V, with resistances of 3 ohms, 6 ohms, and 9 ohms?	11 amps
Four resistors are connected in series to a battery of 6 V, with resistances of 2 ohms, 4 ohms, 5 ohms, and 10 ohms. What is the total resistance?	21 ohms
What is the total current in the series circuit with a battery of 6 V, with resistances of 2 ohms, 4 ohms, 5 ohms, and 7 ohms?	.33 amps
The rotation of electrons on their axis is the property called ____________.	electron spin
An electric potential applied to a conductor produces __________.	Electric current & Magnetic field
Like charges _______ and unlike charges _______.	attract, repel
An alternating (AC) current is represented by a __________ line.	sinusoidal
The charges on an electrified object are distributed __________.	evenly throughout the object
In the United States, alternating current goes through a complete cycle every _____ second.	1/60
Electrification occurs through the movement of ___________.	electrons only
What is the unit of electric potential?	volt
A ___________ uses direct current.	flashlight
Alternating current is produced by a ___________.	generator
The smallest unit of electrical charge is the __________.	electron
A _________ is a source of direct current.	battery
A charged particle in motion creates a(n) ______________.	magnetic field
On the surface of an electrified object, the charges concentrate on the __________.	sharpest curvatures
Electrostatic force is _________ proportional to the distance between charges, and _______ proportional to the product of the charges.	inversely, directly
Electrical power is measured in _____.	watts
What is the unique electron characteristic of magnetic materials?	They all orbit in predominantly one direction.
Lines of magnetic flux traveling in the same direction will attract each other.	Fasle
At what distance would you expect two magnets to have the strongest reaction to each other?	1/8 inch
An iron bar wrapped with a wire carrying electric current is what class of magnet?	Electromagnet
Platinum is magnetically classified as which of the following?	Paramagnetic
Rubbing a ferromagnetic material against a permanent magnet will magnetize that material.	True
Like poles of a magnet or charges of electric fields will:	repel
Which scientist used a compass and a wire carrying electric current to demonstrate and study electromagnetism?	Oersted
If this circle with a dot in the center represents a wire carrying electric current to toward you, which of the following is true?	Magnetic flux lines flow counterclockwise
Depending on the application of the right-hand rule, the thumb can indicate either current flow or direction of the magnetic field.	True
The following describes four different coils. Which one, if moved through a magnetic field, would create the least voltage?	10 turns
If the number of coils of a conductor is 40 and the voltage is 110, what will the voltage be if the number of coils is increased to 80?	220
The north and south ends of an electromagnet change each time an AC changes direction.	true
Which scientist formulated a law that explains a principle of electromagnetic induction?	Lenz
The ability of a material to attract iron, cobalt, or nickel is called	magnetism
The lines of force in space associated with a magnet are called	lines of flux
Inside the magnet, the lines of flux travel from	South Pole to North Pole
Outside the magnet, the lines of flux travel from	North Pole to South Pole
Like poles of a magnet _________ each other and opposite poles ________ each other.	repel; attract
The force of magnetic attraction varies	inversely with the square of the distance between the poles.
Magnetic field strength is measured in	Tesla
A material that is weakly repelled by a magnetic field is classified as	diamagnetic
A material that is strongly attracted to a magnetic field is	ferromagnetic
A material that is weakly attracted to a magnetic field is	paramagnetic
Wood and plastic are considered:	nonmagnetic
The idea that electricity flowing through a conductor produces a magnetic field was identified by	oersted
The idea that electricity could be induced in a wire by moving it through a magnetic field was discovered by	faraday
According to Faraday’s Law of Electromagnet Induction, if the strength of the magnetic field is increased, _________is also increased.	current
An electromagnet includes:	a coil of wire, an iron core, a solenoid.
Reducing the number of coils in the wire will result in	reduced electromagnetic induction.
Increasing the strength of the magnetic field results in	increased electromagnetic induction.
Slowing down the speed at which the conductor passes through the magnetic field results in	reduced electromagnetic induction.
Mutual induction involves electricity being induced into a ______________.	secondary coil
With mutual induction, to induce voltage in the secondary coil, there must be	alternating current in the primary coil of wire.
_______________ current is induced in the secondary coil when mutual induction takes place.	alternating
With self-induction, the secondary current	is in the original coil and opposes the original current.
Self-induction is based on the concepts introduced in	Lenz’s law.
Lines of flux in the same direction attract each other.	false
Lines of flux in the opposite directions attract each other.	true
Nonmagnetic material, when interacting with a magnet, distorts the magnetic field.	false
Every magnet has a north, south, east, and west pole.	false
With alternating current, the north and south poles of the magnetic field surrounding the wire change each time the electrons change direction.	true
What atomic characteristic of a magnetic material creates a dipole?	their electrons spin in predominantely one direction
What aligns to form magnetic domains?	atoms
If a magnetic material is placed in the field of a magnet, what happens to that field?	it is distorted
A magnet is formed when all of its “atomic magnets” align.	true
According to the laws of magnetism, how many poles will an atomic magnet have?	two poles at this level
The south poles of two magnets are placed 1 millimeter from each other. Which of the following describes the reaction?	very strong repulsion
An iron bar exposed to a strong magnetic field may become which of the following?	artificial permanent
Materials strongly attracted to magnets are classified as which of the following?	ferromagnetic
Heating a magnetized iron bar will cause it to lose some or all of its magnetism.	true
Tapping an iron bar against a solid object in a magnetic field will help magnetize that material.	true
Magnetic poles can exist separately from each other and may have only one pole.	false
With electric fields, positive and negative charges exist separately.	true
The inverse square law applies to both electric and magnetic fields.	true
Which scientist conducted experiments demonstrating that a magnetic field created by a flow of electric current was greater than the earth’s magnetic field?	oersted
If this circle with an “x” in the center represents a wire carrying current away from you, which of the following is true?	magnetic flux lines flow clockwise
What is the advantage of configuring a wire carrying electric current into a coil (spring)?	strengthens the magnetic field
The following are four different magnetic fields. If the same coil of wire is passed through each, which will result in the greatest induced voltage?	2.5T
Which of the following conductor angles, in relation to the magnetic field, will produce the greatest voltage?	90 degree angle to the field
The basic premise of electromagnetic induction is that which of the following move?	1 &2 only, (magnetic field)
Why is AC desirable for mutual induction?	it creates a moving magnetic field
What happens to filament electron after they interact with atoms?	1 & 2:Fill a shell vacancy in an atom & Become part of the current through the tube.
Only L shell electrons can fill K shell vacancies.	False
If an N shell electron fills an M shell vacancy, what is the energy of the photon produced?	2.22
If an O shell electron fills an L vacancy, what is the energy of the photon produced?	12.02
If filling a K shell vacancy, which shell electron would produce the highest energy characteristic photon?	O shell
Characteristic photons are produced with the filling of each shell vacancy.	True
L characteristic originates from which of the following shells being filled?	L
As the distance between the filament electron and nucleus gets smaller, what happens to the brems photon energy?	Increase
If a filament electron enters an atom with 70 keV of energy, passes the nucleus and leaves with 10 keV, what is produced?	60 kVp brems
Brems is the interaction that occurs most often.	True
During x-ray production the electrons penetrate the target approximately	.5 mm
X-rays are produced by	characteristic and bremsstrahlung interactions.
When filament electrons enter the anode target, they interact with	outer shell electrons of tungsten atoms
At the anode target, how much of the energy from filament electrons is lost as heat and how much will result in x-ray production.	99% every lost as heat; 1% result in x-ray
When a filament electron knocks out a K shell electron from the tungsten atom, it leads to	a characteristic x-ray photon
Characteristic x-ray photons result	when an inner-shell electron is knocked out and when outer-shell electrons fill the vacancy in an inner shell.
The energy of the characteristic x-ray photon depends on	ALL THE ABOVE: the binding energy of the inner-shell electron, the energy level of the filament electron, the shell of the electron that is dropping into the vacancy.
A filament electron removes a K shell electron and an M shell electron fills the vacancy. The K shell binding energy is 69.5 keV and the M shell binding energy is 2.8 keV. What is the energy of the K-characteristic photon produced?	66.7keV
The process of a series of outer-shell electrons filling inner-shell vacancies right after the other is called	characteristic cascade
Bremsstrahlung means	braking radiation
During the bremsstrahlung interaction, the filament electron	is attracted to the nucleus but not absorbed
The energy of the brems photon depends on	ALL THE ABOVE: the original energy of the filament electron, the strength of the attraction between the electron and the nucleus, the energy of the filament electron as it leaves the tungsten atom
If a filament electron enters the tungsten atom with 80 keV of energy and leaves the atom with 75 keV of energy:	the filament electron traveled very far from the nucleus
If a filament electron leaves the tungsten atom with 15 keV of energy and the brems photon produced was 65 keV, how much energy did the incoming filament electron have?	80 keV
The average energy of a brems photon is ______ of the kVp selected at the control panel.	1/3
The majority of the x-ray photons produced are	brems photons
A discrete emission spectrum is a graphic representation of	characteristic radiation
A continuous emission spectrum is a graphic representation of	bremsstrahlung radiation
The x-ray emission spectrum is a graphic illustration of	characteristic radiation and bremsstrahlung
The x-axis for all emission spectra represents the	energy level of the photons
The y-axis for all emission spectra represents the	number of photons
The discrete emission spectrum typically displays	BOTH OF THESE: K-characteristic & L -characteristic
L-characteristic and higher photon energies are not usually displayed on a discrete emission spectrum because	the energies of the photons produced are too low for image formation.
With a 75-kVp exposure, the energy of the photons displayed on the continuous emission spectrum can range from just above 0 to	75 keV
With a 75-kVp exposure, the peak of the curve on the continuous emission spectrum is approximately	25 keV
With the x-ray emission spectrum, the discrete line is the highest energy ___________________ bar.	K-characteristic
For a tungsten target, the discrete line on the x-ray emission spectrum is approximately	69 keV
Changes along the x-axis of the x-ray emission spectrum reflect changes in the _________________ of the x-ray beam.	quality
If all other factors remain constant, a decrease in the mA results in	a decrease along the y-axis
Increasing the kVp results in	an increase along the y-axis and a shift to the right along the x-axis
Adding filtration in the path of the beam results in the x-ray emission spectrum	BOTH OF THESE: Changing along the x-axis & changing along the y-axis
Changing from a high-frequency generator to a single-phase generator results in the x-ray emission spectrum	BOTH OF THESE: chaining along the x-axis & changing along the y-axis
Changing the ___________________ results in changes to the x-axis, y-axis, and location of the discrete line of the x-ray emission spectrum.	target material
As filament electrons enter the anode target, most interact with inner shell electrons of the tungsten atoms. F/T	False
At the anode target, 1% of the energy from filament electrons is lost as heat and 99% will result in x-ray production T/F	false
A 65-keV filament electron is not able to produce characteristic radiation. T/F	true
When 65 kVp is set on the operating console, no K-characteristic radiation is produced. T/F	True
T/F The stronger the attraction between the filament electron and the nucleus, the less energy the brems photon has.	False
T/F.The discrete emission spectrum is limited to a few specific values.	true
T/F. When the kVp is changed from 60 to 120, the discrete line on the x-ray emission spectrum shifts to the right.	False
Which of the following tissue types is likely to have the greatest number of photoelectric events?	Bone
Which interaction, within the diagnostic range, does not involve the removal of an orbital electron?	Classical
A photon of 10 MeV colliding with a nucleus will likely result in what type of interaction?	photodisintegration
Which kVp will produce the greatest number of photodisintegration events?	None of the above
Which interaction in the diagnostic range involves the total absorption of the incident photon?	photoelectric
The ejection of a nuclear fragment is part of which interaction?	Photodisintegration
When the kVp selected is equal to or slightly greater than the inner shell binding energy of a tissue atom, which interaction predominates?	photoelectric
Secondary photons are also produced during what type of interaction?	photoelectric
Which of the following is an undesirable contributor to image contrast and density?	Compton
During coherent scattering, the scattered photon possesses _____ as the incident photon.	The same energy, the same frequency, and the same wavelength.
T/ F: A filament (projectile) electron will undergo only one interaction.	F
What is the source of energy that results in characteristic photons?	The differences in shell energy levels of the electron filling the vacancy.
If an N shell electron fills a K shell vacancy, what is the energy of the photon produced?	68.9
If an O shell electron fills an M shell vacancy, what is the energy of the photon produced?	2.74
Given vacancies are filled randomly, which shell is most likely to fill an L shell vacancy?	M
If filling a K shell vacancy, which shell would produce the weakest photon?	L
Which shell interaction produces the most useful characteristic photon?	K
Which of the following filament electron energies will remove a K shell electron from a tungsten atom?	70
If a filament electron enters an atom with 100 keV, passes the nucleus and exits with no kinetic energy, what is produced?	100 keV brems
What is the average energy of a beam produced at 90 kVp?	30 keV
In the production of Bremsstrahlung radiation, the incident electron:	Is deflected with resulting energy loss
Characteristic x-rays are produced when:
As electrons impinge on the target surface, more than 99% of their kinetic energy is changed to:	HEAT
Most of the x-rays produced in a tungsten target are:	Bremsstrahlung
At 55 kVp, _____ of the x-rays produced are bremsstrahlung.	100 %
Penetration will result in which shades of the radiographic image?	Dark to black
Penetration is more likely with which photon energy?	high
Which of the following equates to patient dose?	absorption
Differential absorption primarily involves which interaction?	photoelectric
The problem with scatter is that it strikes the image receptor in the wrong place.	true
Which of the following affects quantity?	1, 2& 3: kVp, Mas, Distance
What happens to quality as mAs increases?	unaffected by mAs
Which of the following would increase both the quantity and quality of the primary beam?	kVp
The reduction in x-ray photon intensity as it passes through material is termed:	Attenuation
Basically, an x-ray image results from:	ALL THE ABOVE: direct transmission of x-ray photons, photoelectric absorption, differential absorption
Classical interactions are also known as	Thomson and coherent scattering
Coherent scattering involves	an x-ray photon with low energy
The x-ray photon produced during classical scattering	is the same energy as the incident photon
The x-ray photon produced during classical scattering	travels in a different direction than the incoming photon
Most classical scatter photons	are absorbed in the body
In reference to patient radiation dose, classical scatter interactions	slightly increase dose
The effect of classical scatter interactions on image quality	is minimal
Compton scattering involves the x-ray photon	removing a middle- or outer-shell electron.
Compton scattering typically occurs with x-ray photons in the energy range of	20–40 keV.
Compton scattering typically occurs with	moderate-energy photons.
With Compton scattering, the incident photon	loses up to one third of its energy.
Compton scattering results in	ALL OF THESE: a Compton electron, a secondary electron, a Compton scatter photon
If a middle-shell electron is removed during a Compton interaction	ALL OF THESE: secondary photons are produce, a secondary electron is ejected, a Compton scatter photon is produced
The x-ray photons that are produced as a result of a characteristic cascade during a Compton interaction	are characteristic x-ray photons
Secondary photons produced during a Compton interaction	contribute to patient dose
The Compton electron	has enough energy to produce further interactions
The Compton scatter photon	may exit the patient as part of the remnant radiation and has enough energy to produce further interactions.
When it does interact with the image receptor, the Compton scatter photon contributes no useful information because	it has changed direction
The fog seen on the radiographic image is the result of	Compton interactions
Reducing the amount of Compton scattering	is very important in producing quality images
The greater the angle of deflection of a Compton scatter photon:	the lower the energy of the photon
No matter which direction the Compton scatter photon goes, it retains approximately	two thirds of its energy
The major source of radiation exposure to technologists is due to	Compton interactions
The primary source of radiation exposure to the radiographer who is in the room during an exposure is	from scatter from the patient
To minimize occupational exposure, the technologist should	wear protective apparel ( lead aprons, gloves, etc) when in the room during imaging
For photoelectric interactions to occur, the energy of the incident photon	may be the same or greater than the binding energy of an inner-shell electron
After a photoelectric interaction, the incident photon	loses all of its energy and no longer exists
During a photoelectric interaction,	an inner-shell electron is ejected
The end product(s) of a photoelectric interaction is (are)	a photoelectron and ionized atom
The energy of the photoelectron is equal to	the energy of the incident photon minus the binding energy of the orbital electron
The energy of the photoelectron is the least as a result of a photoelectric interaction in	bone
Photoelectric interactions	contribute significantly to patient dose
Secondary x-ray photons are the result of	Compton and photoelectric interaction produce secondary photons
Photoelectric interactions are more likely to occur in	bone
Protective apparel is often made of lead because it	has a high atomic number
Barium sulfate is used as a contrast agent to visualize soft tissue structures such as the stomach because it	has a high atomic number
Pair production	never occurs during radiographic procedures.
Pair production requires an x-ray photon with an energy of at least	1.02MeV.
Pair production occurs when the incident photon interacts with	the nucleus of the atom
What is produced as a result of pair production, a(n)	portion and electron only
A positron is	a positively charged electron
After ejection from the atom’s nucleus, when the positron interacts with an electron	ALL OF THESE : an annihilation event occurs, the electron and positron are both destroyed, two x-ray photons are produce.
For photodisintegration to occur, the incident photon must have an energy level of at least	10 MeV.
Photodisintegration occurs when the incident photon interacts with	the nucleus of the atom
Following absorption of the incident photon in the atom’s nucleus, a photodisintegration interaction may result in	neutrons and protons being ejected from the nucleus
Photodisintegration interactions	never occur during radiographic procedures
To produce a radiographic image that represents anatomy, there must be	ALL OF THESE: photoelectric interactions, transmitted photons, differential absorption
Radiation interacting with bone is more likely to be absorbed, resulting in that area of the image being	a light shade of gray
Radiation interacting with air is more likely to be _____________, resulting in that area of the image being darker.	transmitted
Dense material, like bone, is considered:	radiopaque
Air is considered:	radiolucent
The greater the absorption of radiation	the greater the patient dose
A breakage of the major structure and framework of the macromolecule as a result of an x-ray interaction is called	main-chain scission
The most radiosensitive molecule in the body is	DNA
Excessive absorption is the result of	using the kVp that is too low for examination
T/F.Potential biological damage can occur as a result of a Compton interaction because of the ionization of atoms.	true
T/F. The probability of Compton scattering depends on the atomic number of the atom.	false
T/F. The probability of Compton scattering depends on the energy level of the incident x-ray photon.	true
T/F. All Compton scatter photons travel in the direction of the image receptor.	false
T/F. The photoelectric interaction and Compton interaction can both result in a characteristic cascade, producing characteristic radiation.	false
T/F. The probability of a photoelectric interaction depends on the atomic number of the atom.	true
T/F. The probability of a photoelectric interaction depends on the energy level of the incident x-ray photon.	true
T/FThe more the energy of the incident x-ray photon exceeds the binding energy of the inner-shell electron, the greater the probability of a photoelectric interaction.	False
T/F.The higher the atomic number of an atom, the greater the probability of a photoelectric interaction.	True
T/F. Without differential absorption, the image would be a single shade of gray.	True
Which interaction is the major source of occupational exposure?
Which type of interaction will only occur with x-ray energies greater than 10 MeV?
Which interaction do we depend on for radiographic contrast?
Which interaction is the primary contributor to image fog?
The total absorption of an incident photon with the ejection of an inner shell electron is the result of which effect?
Which of the following involves the removal of an orbital electron from an atom of target tissue?
Which of the following is the result of excitation of an orbital electron without removing it from its shell?
Compton scatter is dependent on atomic number.
What happens to photoelectric probability as atomic number increases?
Compton scattering occurs when an incident x-ray photon interacts with a(n):
As the angle of deflection of a Compton scattered photon and the recoil electron is increased from 0° to 180°:
Compton interactions:
Which of the following photon interactions require a minimum energy of 1.02 MeV?
An incident x-ray interacts with an atom without ionization during?
When x-ray photons interact with matter and change direction, the process is called:
The photoelectric process is an interaction between an x-ray photon and:
At energies below 40 keV, the predominant x-ray interaction in soft tissue and bone is _____.
The probability of a photoelectric interaction is higher with:
Absorption will result in which shades of the radiographic image?
What happens to absorption as kVp increases?
What happens to scatter as kVp increases?
If kVp is doubled, what happens to quantity?
Half-value layer is a measure of quality.
Which of the following would absorb the least x-rays?
Which of the following would absorb the most x-rays?
Which of the following would decrease the quantity, but increase the quality of the primary beam?
The reduction in x-ray photon intensity as it passes through material is termed:
When the mass density of an absorber is increased, Photoelectric absorption ______________.
Differential absorption is dependent on (the) _____.
Attenuation is caused by:
The penetrability of an x-ray beam is called x-ray:
The number of useful x-rays in the beam defines x-ray:
An x-ray beam that could pass through dense tissue would have high:
X-ray quantity increases in direct proportion to increases in:

Created by: Thuythi15

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