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Radiology physics

physics 1

QuestionAnswer
The atomic mass for any element is: Equal to the number of protons and neutrons in the nucleus of the atom.
If an atom has16 protons and 16 electrons, how many electrons are orbiting in the M shell? 6
What is true about isotopes? An isotope has the same number of protons but a different number of neutrons.
What is the relationship between wavelength and frequency? As wavelength increases, frequency decreases.
What are the atomic particles that carry an electrical charge? Protons and electrons
The atomic number given to an element is: The sum of the number of protons in the nucleus.
The one property that is common with all of the energies found in the electromagnetic spectrum is: Velocity
The octet rule states that any atom cannot have more than 8 orbiting shells. False
Using the formula 2 x N squared and given that the M shell of the electron orbit has the number 3 (N). How many electrons will occupy this shell if it is not the outermost shell? 18
A proton is roughly _____ times larger than an electron. 1800
There are two forces, the first is the attractive electrostatic force and that pulls the electron towards the nucleus and the _____ pulls the electron away from the nucleus and prevents the electron from moving closer to the nucleus. Centrifugal forcce
When 2 or more atoms are chemically united, they form a/an: Molecule
One kilogram is equal to: 1000 cubic centimeters of water at 0 C.
The current model of the atom that is considered most representative to the structure of matter is the: Bohr model
Nucleons consist of: Protons and Neutrons
The binding energy that holds an electron in its shell around an atom: Increases as you get closer to the nucleus, and is higher in electrons from higher atomic numbers than from lower atomic numbers
What is the maximum number of electrons that can orbit in the P-shell if the P-shell is not the outermost shell of that atom? 72
X-ray wavelengths are measured in: angstroms
If the N shell of an electron orbit is the outermost shell, what is the maximum number of electrons that you will find in that shell? 8
In the United States, the standard current that comes into our homes is: AC
Increasing the temperature in a circuit also increases the: Resistance
Increases in Resistance in a circuit can be from: Increase conductor length, decrease diameter of tube, increase in temperature.
Which of the following metals makes a better conductor? Gold, Silver, Al Gold
What is the unit of Power The Watt
1 Watt is produced by 1 ampere flowing with a pressure of one volt.
What is the equation for computing Watts P = V x I
The Watts on the primary side of the of the transformer has to equal the watts on the secondary side. T/F True
One kilovolt equals how many volts 1000
What is the resistance of a circuit if the voltage is 24 V and the current is 60 amperes? .4
What is voltage if the current is 30 amperes and the resistance is 10? 300 volts
What is the amperage if you have 20 kilovolts and a resistance of 30. 666.67
What is the resistance if you have 40 volts and 40 milliamps? 1,000 ohms
How many milliamps are in an Ampere 1,000
______ is the force or electrical pressure that produces electron movement and current flow. Voltage
The greatest concentration of charge in a solid metallic wire will be: On the outside surface at an area of sharpest curvature.
One ampere is equal to ______. 1 coulomb flowing per second
66 kilovolts carrying 500 amperes will have a resistance of: 132 ohms
Increasing the length of a conductor will also increase: Resistance
According to ohm’s law, the current in a circuit with 120 volts and a resistance of 5 ohms is: 24 ampere
According to the Laws of Electrostatics, unlike charges will repel one another. False
Unlike charges ____ each other Attract
What is the unit of current? Ampere
A semiconductor can be classified as: A conductor and an insulator
If the electricity to your home costs $.75 per kilowatt hour and you operate a 2000 watt vacuum cleaner for 30 minutes, what is your cost for this period of time? $.75
Charges will tend to reside on the external surface of a conductor. T/F True
Electric power (the watt) is determined by the formula: Volts multiplied by amperes equals watts
If a cicuit is carrying 500 volts and has a resistance of 1 ohm, the amperage in this circuit is 500 T/F True
Objects can be electrified by one of three methods. What are these methods Friction, Contact, Induction
Resistance is: Increased when the conductor diameter gets smaller.
According to ohm’s law, the current in a circuit with 10,000 volts and a resistance of 50 ohms is: 200
The relationship between current and a changing magnetic field is called: Electromagnetic induction
An autotransformer operates on mutual induction. False
What type of transformer runs on Self Induction Autotransformer
It is possible to step-up both the voltage and amperage together with a transformer. T/F False
. If a transformer has 400 coils on the primary side and 200 coils on the secondary side, this type of transformer is a: Step Down
If you Increase voltage from the primary side to the secondary side of the transformer it is a ___ transformer Step Up
Which of the following types of materials has high permeability? Ferromagnetic
A device that converts mechanical energy to electrical energy is called a/an: Generator
A device that converts electrical energy into mechanical is called a/an: Motor
The type of transformer that can both increase and decrease a voltage in a circuit is known as a/an: autotransfomer
You have a current of 100 volts and 2 amperes on the primary side of your autotransformer. In order to get 10 amperes on the secondary side of your transformer, you must _______ the voltage to ______ volts. step-down, 20
A series of coils of wire within proximity of each other will create a combined magnetic field that can be used as a tool. This device is known as a _______. Solenoid
If the current on the primary side of your step-down transformer is 10,000 volts and the current on the secondary side is 500 volts, how many coils are located in the secondary side if the primary side of the transformer has 100 coils? 5
. A device that can take a DC current and turn it on and off several times per second in order to create an AC current is called a/an: Inverter
A device that is used in portable x-ray machines that can accumulate and store an electrical charge is a/an: Capacitor
Rectification of AC current is necessary for: Changing the current from AC to DC for devices like x-ray tubes and televisions.
Groups of atoms with their magnetic moments or net magnetic field in the same direction are known as: dipoles
If a material has high permeability (easily magnetized), it will have ______ retentivity. Low Retentivity
Permeability and Retentivity are ____ proportional to each other Inversely
The input watts on the primary side of a transformer should equal the output watts on the secondary side of that transformer. True
The type of magnet that is produced by heating an alloy within a strong magnetic field is: Artificial Permanent
Holding a stationary conductor in a stationary electric field will produce a current in that conductor.t/f False
. If a transformer has an input of 200 V and 40 amps on the primary side, the output in watts on the secondary side will be: 8000 W
Half wave rectification of the power coming into an x-ray machine will utilize only 50% of the incoming power.T/F True
What is the cost to run your hairdryer if it uses 1500 watts and you operate it for 15 minutes. The electric co charges you 80 cents per kilowatt hour? .30 cents
The speed in which the incident electrons attain before reaching the anode target is approximately: Half the speed of light
The type of personnel monitoring device that can measure exposures as low as 1 mrem and can detect whether an exposure was dynamic or static is: OSL
Beta particles are identical to ______ except for their origin. electrons
Which of the following movements of orbiting electrons is the only one that will produce a photon in the diagnostic range? O shell to K shell
At a setting of 68 kVp with a tungsten anode, the percentage of your beam is composed of characteristic x-rays is: Zero
Tungsten atoms have ___ electrons orbiting their nuclei. 74
The type of radiation that is produced by an incident electron interacting with the nuclei of a target atom is: Bremsstruhlung
The most common type of personnel monitoring device used in Radiology is the: OSL
If an x-ray tube uses a molybdenum anode, the K-shell Characteristic peak is about: 18 keV
The type of field survey instrument that is only good at detecting particulate radiations and does not provide measurement of exposure is the: Geiger-Mueller survey instrument
If during a procedure, a patient's skin started turning red from a prolonged exposure, this would be considered a _______ effect. Somatic
As the kinetic energy of the incident electrons increases, so does: The efficiency in which photons are produced.
An alpha particle is composed of : Two protons and two neutrons.
The binding energy of a O shell electron in a tungsten atom is: 0.08 keV
The atomic number for Beryillium is 4
If the leakage radiation measured at 2 meters from the tube housing is 80 mR/hr, what is it if it's measured at 1 meter from the housing? 320 mR/hr
Total filtration is a combination of inherent filtration and added filtration.
. A technique used at 40" will need to be increased by a factor of ____ if the distance is doubled. 4
A technique of 75 kVp at 24 mAs W/ 80" SID needs to be changed to an SID of 20”. Your new technique should be: 75 kVp at 1.5 mAs
Most of the exposure to film when using a film/screen combination is a result from the production of: Light
The prime factors that control quantity and are controlled by the technologist are mAs, kVp, and distance
A known technique of 110 kVp and 8 mAs worked well for a chest x-ray done at 40" on a large patient. If the distance needed to be increased to 66", your new technique should be 110 kVp at ____ mAs. 22 mAs
Which of the following techniques will equal a change in density by a factor of 4 by employing the 15% rule? Your original technique was 80 kVp at 8 mAs. 106 kVp at 8 mAs
The Reciprocity Law basically states that any combination of mA and time that equal the same mAs will create the same density on a radiograph when all other factors are the same. True
When using a compensating filter, the thinnest part of the filter should be in-line with the thickest part of the body part.T/F True
To reduce the attenuation of soft x-rays, mammography tubes use: A Beryillium window on the tube housing.
The atomic # for Al is: 13
15% of 48 is: 7.2
A good technique done at 60" is 85 kVp at 8 mAs. If you were to decrease your distance to 40" and not change the kVp, your new mAs should be: 3.5 mAs
All diagnostic x-ray machines must have a minimum filtration of: 2.5mm al/Eq
When altering techniques for increases or decreases in density, the primary controller of x-ray intensity is kVp and the 15% rule should be employed before changing the mAs.T/F False
When added filtration is added to the beam, what happens to the average energy of the beam on the emission spectrum? The average energy of the beam increases.
Which of the following equations would you use to compute the difference in intensity of electromagnetic radiations, when measured at different distances, when a known intensity exists? I2 =I1(d1/d2)squared
The type of interaction that produces two photons of 0.51 Megavolts is: Pair Production
The Characteristic cascade is an event that is associated with which type of interaction? Photoelectric
Which of the following interactions increases as kVp increases? Comptons
The kind of interaction that excites the nucleus and causes a nuclear fragment to be released is known as: photodisinigration
Hydrogen, carbon, and oxygen all have K-shell binding energies of: Less than 1 keV
During a Compton's interaction, when a photon strikes an electron and reverses direction back towards the source is called: Back scatter
When just comparing body tissues, soft tissues interactions are about 50/50 Compton's and Photoelectric at about: 26 keV
During a compton's interaction, the incident photon will continue on after the interaction in another direction with a higher frequency and shorter wavelength.T/F False
In the diagnostic imaging range, most of the photons that strike the patient are: Attenuated
With photoelectric interactions, the secondary photons produced when radiating Barium and Iodine will have higher frequencies than when x-raying only soft tissue of the body. T/F True
Which two of the following interactions ARE NOT of significance in diagnostic radiology? Coherent Pair Production
The type of interaction that involves an outer shell electron, an incident photon and causes scatter radiation that is ionizing to the patient and anyone else standing nearby is: Comptons
As kVp increases the total number of photons that are transmitted without interactions _______. Increases
Higher kVp and low mAs will cause less patient dose than low kVp and high mAs.T/F True
What is the unit of mass Kilogram
1 kilogram equals ___grams 1,000
When two or more atoms are chemically united they form a : Molecule
Which attraction is of water is the weakest: Ice, gas/steam, or liquid gas/steam
What is the unit of energy The Joule
What is a nucleon? A proton and nucleus
What is a quark? subnuclear structures in protons and neutrons
What contains no charge and is thought of to be electronically neutral? neutron
The number of protons and the number of neutrons are equal in a ____ atom Neutral
If an atom gains or loses neutrons it becomes an___ isotope
If an atom gains or loses an electron it becomes an___ ion
When an electron is added to an atom it becomes ____ ion negative
When an electron is taken away from an atom it becomes a more ____ ion positive
What are the two opposing forces that contribute to the stability of an electrons orbit: The attractive electrostatic force and The centrifugal force
What formula can you use to determine the maximum number of electrons that can orbit each shell? 2n^2
What is the maximum number of electrons that can be in the L shell? 8
What is the maximum number of electrons that can be in the Q shell? 98
What is the maximum number of electrons that can be in the N shell? 32
The x-ray energy must be ____ than the binding energy of the electron in order for ionization to occur. greater
Electrical energy or electricity is the result of the movement of electrons. T/F True
Gamma rays originate from: the nucleus of a radioactive material
x-rays originate in an : x-ray tube
If the frequency of an x-rays doubled, the energy is ____ doubled
Only negative charges move along solid conductors. T/F True
objects can be electrified by three methods: Friction, Contact, Induction
what are the materials that easily permit electrons to flow facilitate the movement of electrons conductors and superconductors
Nonconducting materials are _____ insulators
Electrons move from an are of ____ concentration to an area of ____ concentration High, low
DC current comes from a continuous source such as a battery, T/F True
What is the unit of current The ampere
1 Amp = 1coloumb/per second
What is the unit of resistance The ohm
What is the amperage in a circuit of 20 V and 10 ohms? 2
Let's do another one: what is the voltage in a circuit of 100 amperes and 5 ohms? 500
What is the resistance in a circuit of 80 kilovolts and 200 mA? 400,000 ohms
what is the power rating, in kilowatts, of an x-ray generator capable of 800 mA at 100 kV? 80,000 watts or 80 kilowatts
In nonmagnetic objects the magnetic dipoles are randomly arranged, essentially canceling out each other. T/F True
The force fields that are created when magnetic dipoles orient to create a magnet are called lines of ____, lines of ____ or the _____ force, flux,magnetic field
The SI unit for magnetic flux is the ___ Weber
_____are created when iron oxide remains in the earth's magnetic field for ages, slowly orienting the magnetic dipoles in the same direction. Natural magnet (lodestones)
____ are temporary magnets produced by moving or changing electric current. electromagnets
When a non-magnetized iron bar is brought within the lines of force of a strong magnet, the dipoles will temporarily align themselves with the lines of force passing through the iron bar, this describes ___ magnetic induction
Adding ferromagnetic materials _____magnetivity increases
_____are actually weakly repelled by all magnetic fields, including both North and South Poles. water is slightly ____ diamagnetic
____ have low permeability and weak attraction to magnetic fields. This includes ____ & ____ Paramagnetic, Aluminum & Platinum
Nonmagnetic materials consist of plastic, wood,glass and rubber
if a transformer is supplied with 400 V to the primary coil, has 100 turns of wire on the primary coil, and 20,000 turns of wire on the secondary coil, what will the voltage be in the secondary coil? 80,000 V
If a transformer has 120 turns of wire on the primary coil, 80 V in the primary coil, and 120 V in the secondary coil, how many turns of wire must there be in the secondary coil? 180
Transformers can only work on ____ current Alternating current
if you are using a step up transformer that has 200 V and 16 amps on the primary side and on the secondary side you have 800 V, what is the amperage on the secondary side of this step up transformer? 4
what is the dmf New mas = old mas (D2/D1)^2
What is the inverse square law New intensity = old intensity (D1/D2)^2
What is the transformer law V2/V1= N2/N1
What is ohms law? V=IxR
What is the Atomic number of carbon? C 6
What is the Atomic number of oxygen O 8
What is the Atomic number of molybdenum Mo 42
What is the Atomic number of Calcium Ca 20
What is the Atomic number of radon Rn 86
What is the Atomic number of barium Ba 56
What is the Atomic number of aluminum Al 1
What is the Atomic number of iodine I 53
What is the Atomic number of lead Pb 82
What is the Atomic number of tungsten W 74
If your beam energy is 70 kvp or above how much of your beam is composed of Characteristic and Bremsstruhlung 69 & below = 100% Brehmsstruhlung 70 & above = 10-20% Characteristic & 80-90% Bremsstruhlung
How many centimeters equals an inch? 2.5
1 cm equals how many mm and meters? 10 mm or 1/100 meter
Nearly all x-ray equipment operates from incoming line of _____ 210-220 volts.
26. How many pulses will you get using a single phase half-wave rectified wave form vs. a full-wave rectified waveform? With single-phase half-wave rectification, photon production starts and stops 60 times a second. Productive 50% of the time. Full-wave rectification starts and stops 120 times a second but is producing photons almost 100% of the time.
Generators must terminate the exposure at ___mAs for exposures above 50 KVP 600 mAs
Generators must terminate the exposure at ____ mAs for exposures below 50 KVP. 2000 mAs
What is the only part of the cathode or anode that is located outside the glass envelope. stator
Wavelengths are measured in? Angstrom
If you increase frequency you are ____ wavelength decreasing
A filament is composed of? a small coil of thin thoriated tungsten wire
What is a focusing cup made out of? nickel
What is the binding energy of a k shell electron in a tungsten atom? 69.5 kev
110 volts x 3 amps = 330 watts
what are the two types of currents used in our homes and appliances? AC & DC
What is the device used to increase or decrease the voltage and amperage in an alternating current transformer
a full wave rectified current will turn on and off ___ times per second 120
The current that passes through the x-ray tube is ___ DC
What carries more amperage; tube current or filament filament current
in older machines, valve tubes were used to... rectify an ac current
80 kv and 200 mA = ____ ohms 400,000
if there are more coils on the secondary side of a transformer it is a ____ ___ transformer Step Up
Is the conversion of voltage in a transformer proportional to the ratio of coils? yes
What is the unit of measurement for large magnets? Tesla
What is the unit of measurement for small magnets? gauss
1 tesla = ____ gauss 10,000
What kind of x-ray tube can pulse the beam? Grid controlled/grid biased tube
What do you call the electromagnets that drive the rotor? Stators
The anode target is backed by what heat resistant metal? Molybdenum
If an exposure takes 1 full second on a 100 speed film cassette how long will it take on a 400 speed if the mAs stay the same? .25 or 1/4th the speed
Hand x-ray used 55 kvp @ mAs on a 400 speed cassette. What if I used a 200 speed cassette. 55 kvp @ ___ mAs 4
single phase machine. 6 exposures of 80 kvp @ 32 mAs = ___ HU 15,360
If you have 100 mR/HR of leakage radiation at 1 meter from your tube how much do you have at 2000 millimeters? 25 mR/HR
If you have 50 mR/HR of leakage radiation at 100 cm from your tube how much do you have at 50 cm? 200 mR/HR
400 mA at 1/5th a second = ___ mAs 80 mAs
300 mA for 1.25 seconds = ___ mAs 375
500 mAs for 1/10th of a second = ____ mAs 50
800 mA for .001 seconds = ____ mAs .8 mAs
High frequency (1.40) 5 exp. of 90 kvp @ 24 mAs + 3 exp. of 75 kVp @ 40 mAs 27,720
3phase (1.35) 7 exp. of 65 kVp at 10 mAs + 7 exp. of 76 kVp @ 12 mAs 14,760.9
If a single photon has 41 keV of energy is it Bremsstruhlung or Characteristic? Bremsstruhlung
What is the maximum characteristic photon (keV) produced by a tungsten target 69.5
Which end of the tube is positive and which end is negative? anode, cathode
What does OSL stand for? Optically stimulated luminescence
Ring badges are TLDs or OSLs TLDS
Film Badges are TLDs or OSLs OSLs
AC current in the US flows at a rate of ___ Hertz 60
If an atom has 6 electrons and is not a positive ion, then the atomic number of that atom is __ 6
Odontoids use 74 kVp at 20 mAs at 40". How much would you use if your SID was 12" 1.8 mAs
60 mAs at 36" will create the same density as ____ mAs at 72" 240
If you increase your SID from 40" to 72" you will need to increase your mAs by ___ times 3.24
You produce a good xray at 40" using 66 kVp at 10 mAs. What mAs should you use if this was done at 60"? 22.5 mAs
You produce a light xray and discover that your SID was 56" instead of 40". Since technique was 75 kVp at 32 mAs, what should you have used? 62.72
100 cm is approximately ____ inches 40
If you want to increase your density by a factor of 4, you can accomplish this by reducing your SID by half
The two most common grid errors are: Off level and Off Center
Employing use of Grid ____ patient Dose Increases
You can use an angle on a grid if you ____ Angle the beam with the grid lines
Shoulder with a 6:1 grid was 18mAs. How much without a grid. 6 mAs
Pelvis without a grid was 10 mAs, how much would you use with a 8:1 grid. 40 mAs
Grid lines are 2mm high and the interspace is .25 wide. What is the ratio? 8:1
Linear focused Grid cannot be used ____ Upside down
This grid has lines in two different directions Cross-hatched
Converting data back into analog information for viewing on a monitor requires the information to be passed through the DAC (digital to analog converter)
Image transmission within a hospital happens via the ______ Intranet
Conversion of an image into digital data requires the use of the: ACD (analog to digital converter)
If you needed to 'complete' an exam, which of the following programs would you access an order to do this? (HIS, RIS, HL-7, PACS) RIS
The heart of a PACS system is a high-end computer or server. (T/F) True
One advantage that digital mammography has over conventional film mammography is (CAD) Computer Aided Diagnosis
Two popular types of compression used to send images quickly are: Lossy & Lossless
CR and DR systems actually had better spatial resolution than Conventional film systems. (T/F) False, They have worse, but can make it up via post-processing
If you needed to view a patient's History and Physical(H&P) report, you would find this in: HIS
DICOM is used to send images to and from PACS. What is the software used to send text between the RIS and HIS? HL-7
Created by: smliger