Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

:] > Physics Ch. 2-7 > Flashcards

Physics Ch. 2-7 Flashcards

1
Q

Define matter

A

anything that occupies space and has shape or form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the three basic forms of matter?

A
  • solid
  • liquid
  • gas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

define mass

A
  • quantity if matter that makes up any physical object
  • weight
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is an example of mass

A

a 20lb bucket of water may freeze into a 20lb bucket of ice or it may evaporate, resulting in 20lb of water vapor. The form changes, but the mass remains the same.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

define the Law of Conservation

A
  • Matter can be neither created nor destroyed, but it can change form.
  • Energy can be neither created nor destroyed, but it can change form.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

define atom

A

basic building block of matter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are the three fundamental components/particles of an atom?

A
  • protons
  • neutrons
  • electrons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what two fundamental particles make up the nucleus?

A

protons and neutrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

where are electrons located in an atom?

A

they encircle around the nucleus in orbits called shells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is the charge of protons?

A

positive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the charge of neutrons?

A

no charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the charge of electrons?

A

negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

atoms can be ____ or _____

A

neutral or ionized

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

define a neutral atom

A
  • normal/neutral state
  • the atom has an equal number of protons and electrons
  • electric charges are equal
  • the atom has no charge
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

define ionized

A

contain a lesser or greater amount of electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how many shells are in an atom?

A

7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are the names of the shells?

A

1 - k
2 - l
3 - m
4 - n
5 - o
6 - p
7 - q

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the maximum number of electrons a K shell can have?

A

2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is the maximum number of electrons an L shell can have?

A

8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is the maximum number of electrons an M shell can have?

A

18

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is the maximum number of electrons an N shell can have?

A

32

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is the maximum numbers of electrons an O shell can have?

A

50

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is the maximum numbers of electrons a P shell can have?

A

72

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is the maximum numbers of electrons a Q shell can have?

A

98

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

which shell is the most important in radiology?

A

k-shell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

define anion

A

when the atom gains an electron, changing the neutral charge into a negative charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

define cation

A

when the atom loses an electron, changing the neutral charge into a positive charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

define binding energy

A

a strong nuclear force that holds the nucleus and electrons together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

define element

A

a substance made up of only 1 type of atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what are some examples of elements?

A

calcium (Ca)
iodine (I)
lead (Pb)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

define atomic number

A

number that represents the number of protons in a nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

why is a lead bullet easier to see in an x-ray rather than a calcium stone?

A

lead has an atomic number of 82, making it have a higher mass, and more density compared to calcium, which has an atomic number of 20

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

define mass number

A

combined total of protons and neutrons in the nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

how do you find the amount of neutrons in an element?

A

subtract the atomic number by the mass number

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

define molecules

A

when two or more atoms are combined

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

define chemical compound

A

a substance that consists of one type of molecule
ex.) water (H2O)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

define mixtures

A

substances that contain more than one type of molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

define energy

A

the ability to do work

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

which shell has the greatest binding energy? Why?

A

k shell because it is the closet to the nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

define chemical compounds

A

combination of elements bonded together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

define potential energy

A

energy at rest
- “stored” energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

define kinetic energy

A

energy in motion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

what are the classifications of energy?

A
  • mechanical
  • chemical
  • thermal
  • nuclear
  • electric
  • electromagnetic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

define mechanical evergy

A

can be classified as kinetic or potential energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

define chemical energy

A

energy released through chemical changes in atoms or molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

what is an example of chemical energy?

A

batteries, gasoline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

define thermal energy

A

commonly known as heat, and is the result of atomic motion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

whats an example of thermal energy?

A

when heated, electrons move rapidly. when cooled, electrons constrict

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

define nuclear energy

A

energy released by radionuclides
- energy used to produce electricity in a nuclear power plant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

define electric energy

A

the ability of electric charges to do work

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

what are examples of electric energy?

A
  • run computers
  • make toast
  • battery
  • unused wall socket
  • turning on a flashlight
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

define electromagnetic energy

A

has both electric and magnetic properties, changing the field through which they pass both electrically and magnetically
- includes light, x-rays, radio waves, and microwaves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

define sine wave

A

a repeating wave/pattern
- also known as sinusoidal form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

electromagnetic energy occurs in the form of a -

A

sine wave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

define amplitude

A
  • height of the wave
  • distance between the trough and the crest of a sine wave
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

define wavelength

A

the distance from one crest to another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

define frequency

A

the number of times per second that a crest passes a given point

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

what is the relationship between wavelength and frequency?

A

inverse relationship
- the higher the frequency, the shorter the wavelength
- the lower the frequency, the longer the wavelength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

how can one find the velocity of a sine wave?

A

velocity = wavelength x frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

what is the velocity/speed of electromagnetic waves?

A

186,000 miles/sec

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

when the x-ray has a higher energy, that means they have higher

A

penetration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

what is the relationship between energy (kVp) and frequency?

A

direct
- when energy increases, frequency increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

what is the relationship between energy (kVp) and wavelength?

A

inverse
- when energy increases, wavelength decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

all electromagnetic radiation has the _____ velocity

A

same

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

define ionizing radiation

A
  • sufficient energy to remove an electron from its orbit
  • wavelength of 1nm or less
  • x-rays are one form of ionizing radiation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

define photon

A
  • smallest possible unit of electromagnetic energy
  • tiny bundle of energy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

list characteristics of x-rays

A
  • travel in straight lines at a speed of 186,000 miles/sec
  • have no mass
  • highly penetrating and invisible
  • are electrically neutral
  • produced over a wide range of energies and wavelengths
  • travel in straight lines at the speed of light
  • can ionize matter
  • produce biological changes in tissues
  • produce secondary and scatter radiation
  • cannot be detected by human senses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

why are x-rays unique?

A

they have very high frequency and short wavelengths

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

are x-rays naturally produced or man made?

A

man made

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

electricity is used to -

A

produce x-rays

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

define electric current

A
  • number of negative electrons flowing toward a positive charge
  • circuit is the path over which electrons move
  • measurement unit = ampere (A)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

define circuit

A
  • path over which electrons move
  • continuous path
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

define potential difference

A

difference in electric charge between two points in the circuit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

how is current produced?

A

when negatively charged electrons flow toward a positive charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

what are three electric factors that are part of an electric circuit?

A
  • resistance
  • current
  • potential difference
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

define resistance

A
  • any property of the circuit that opposes or hinders the flow of current
  • amount depends on conductor material, length, diameter, and temperature
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

define current

A

the quantity of electrons flowing in a circuit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

define ampere

A

unit used to measure the rate, or volume, or current flow in the circuit
- abbreviated A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

define potential difference

A

the force or speed of the electron flow in the current
- measurement unit = volt (V)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

define volt

A

the unit used to measure potential difference
- abbreviated V

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

what are the units of measurements for current?

A
  • Ampere = A
  • milliampere = mA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

what are the units of measurements for kilovoltage?

A
  • Volt = V
  • kilovolt peak = kVp
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

define electric circuit

A

continuous path for the flow of electric charges from the power source through one or more electric devices and back to the source

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

what is the symbol for an anmeter?

A

a circle with the letter A inside

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

what is the function of the anmeter?

A

measures electric current

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

what is the symbol for voltmeter?

A

a circle with the letter V inside

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

what is the function of the voltmeter

A

measures electric potential

88
Q

what is the symbol for a transformer?

A

coils

89
Q

what is the function of a transformer?

A

increases or decreases voltage by fixed amount (alternating current only)

90
Q

what is the symbol of a diode?

A

a line with an arrow

91
Q

what is the function of a diode?

A

allows electrons to flow in only one direction

92
Q

define alternating current (A-C)

A

-current flow changes or alternates directions at a rate of 60 cycles per second or 60 Hz in the U.S and Canada
- electric current is constantly changing
- current flow increases, peaks, and declines

93
Q

what is the unit of electromagnetic frequency?

A

Hertz (Hz)

94
Q

define rectification

A
  • changing AC to DC
  • AC is converted to flow in one direction only
95
Q

does x-ray production rely on AC or DC?

A

DC

96
Q

define direct current (D-C)

A

current flows at a constant rate in one direction from the positive pole (anode) to the negative pole (cathode)

97
Q

using volts, how is a household circuit different from an x-ray circuit?

A

household: electric current is 120 V
x-ray circuit: electric current is 40,000-125,000 V

98
Q

define electromagnetic induction

A
  • a conductor is placed in a magnetic field and there is movement between the lines of magnetic force and the conductor, electric current will flow in the conductor
  • moving a conductor within a magnetic field will produce AC
  • moving a magnetic field across a conductor also produces AC
99
Q

what is the primary purpose of a transformer?

A

change voltage by means of electromagnetic induction
- the primary and secondary coils will have different voltages

100
Q

define step-up transformer

A

when there are more windings in the secondary coil than the primary coil
- voltage is higher on the secondary side
- kilovoltage increases, amperage decreases

101
Q

define step-down transformer

A

when there are more windings in the primary coil than the secondary coil
- voltage is higher on the primary side
- kilovoltage decreases, amperage increases

102
Q

what is the relationship between kilovoltage and amperage?

A
  • inverse relationship
  • shown in step up and step down transformers
  • when kilovoltage increases, amperage decreases
103
Q

what are the requirements to produce x-rays?

A
  • vacuum
  • source of electrons
  • target for electrons
  • high potential difference or voltage between the electron source and the target
104
Q

what are the different parts of an x-ray tube?

A
  • glass envelope
  • cathode
  • filaments
  • focusing cup
  • anode
  • stator
  • rotor
  • bearings
  • anode stem
  • tungsten anode disk
  • tube window
  • tube housing
105
Q

define glass envelope

A
  • pyrex glass
  • heat resistant glass
  • houses the anode and cathode
  • produces a sealed tight vacuum so air does not interfere with the x-rays
106
Q

define protective housing

A
  • lead lined metal protective housing
  • absorbs photons that travel in different directions (other than the patient)
  • contains an oil bath and cooling fans to help dissipate heat
107
Q

define anode

A
  • positive side of the tube
  • also known as the target (for electrons)
  • designed to dissipate heat
  • made up of tungsten
108
Q

define cathode

A
  • negative side of the tube
  • where thermionic emission is done
  • where filaments are located
109
Q

define induction motor

A
110
Q

define filament

A
  • source of electrons
  • made up of tungsten
  • located in the cathode to produce thermionic emission
111
Q

why is tungsten used in the tube?

A
  • contains 74 electrons
  • has a high melting point, therefore, will not melt easily
112
Q

define thermionic emission

A
  • boiling off electrons
  • with heat, electrons move at a rapid rate, forming an electron cloud made up of a strong negative charge
113
Q

define space charge

A
  • cloud of electrons
  • the source of free electrons for x-ray production
114
Q

define electron stream

A

when electrons move rapidly to the anode, attracted from its high positive charge
- pathway

115
Q

what is the percentage of x-ray production when the electrons collide with the anode target?

A
  • 99% heat
  • 1% x-ray photons
116
Q

what two types of interactions are produced after the collision with the anode?

A

bremsstrahlung and characteristic

117
Q

define bremmstrahlung

A
  • when an incoming electron gets attracted to Tungsten’s nucleus. as it gets closer, it slows down and changes directions
  • from the change of direction, it loses energy, creating an x-ray photon
118
Q

what does bremsstrahlung mean?

A

breaking radiation

119
Q

define characteristic

A
  • when an incoming electron collides with an electron in the (inner) k-shell
  • ejects the electron from the orbit, producing an x-ray photon
  • other electrons from the orbit will fill in the empty space
120
Q

above 70 kVp, what is the percentage of bremss that are being produced?

A

85%

121
Q

above 70 kVp, what is the percentage of characteristics that are being produced?

A

15%

122
Q

are x-rays homogenous or heterogeneous?

A

heterogenous

123
Q

why are xrays heterogenous?

A

they are made up of many different wavelengths and energies

124
Q

what is the unit of measurement for x-ray energies?

A

kiloelectron volts (KeV)

125
Q

define dual-focus tubes

A

tubes that contain two filaments instead of one

126
Q

define focusing cup

A

hollow areas in the cathode that houses the filaments

127
Q

define actual focal spot

A
  • measurement of focal spot on target surface
  • affects tube heat capacity
  • bigger is better
  • target area struck by electrons during an exposure
128
Q

define effective focal spot

A
  • measurement of vertical projection of actual focal spot
  • affects image resolution
  • smaller is better
  • target area from which x-rays are projected toward the IR
129
Q

list factors when a small filament is used

A
  • directed to a small focal spot
  • fewer x-rays
  • higher spatial resolution
  • used for small and medium patients
  • less heat
130
Q

list factors when a large filament is used

A
  • directed to a large focal spot
  • more x-rays
  • less spatial resolution
  • used for large and denser patients
  • more heat
131
Q

what is the function of the anode?

A

to dissipate heat

132
Q

what are two types of anodes?

A

stationary and rotating anode

133
Q

which anode is beneficial and why?

A
  • rotating anode
  • with the anode spinning, the heat is distributed all around the circumference of the disk, allowing the anode to last longer compared to a stationary anode
134
Q

what is used to move the anode?

A

electromagnetic induction motor

135
Q

what is the standard speed of the anode?

A

3,600 rpm (revolutions per minute)

136
Q

what is the high frequency speed of the anode?

A

10,000 rpm

137
Q

what causes the anode to “kick in” into a speed of 10,000 rpm?

A
  • when a high technique is used
  • high-speed rotation automatically engages when high exposure factors (kVp, mA, and exposure time) are reached.
  • allows to dissipate heat more efficiently
138
Q

define target angle

A

the slant of the anode surface
- angles between 7-17 degrees, witch 12 being the most common

139
Q

what factors does the anode angle affect?

A
  • tube’s heat capacity
  • sharpness of the image
  • maximum size of the x-ray beam
140
Q

define line focus principle

A

*The size of the effective focal spot determines image resolution.
*The relative size of the effective focal spot is determined by the target angle.
*The steeper the target angle, the greater the difference between the actual and the effective focal spot sizes.

141
Q

what is the size of the small focal spot?

A

0.6 mm

142
Q

what is the size of the large focal spot?

A

1.2 mm

143
Q

how does the anode angle affect the effective focal spot?

A

if the angle is steeper (more vertical/smaller), the smaller the effective spot will be

144
Q

why is a small effective spot desirable?

A

for greater resolution

145
Q

why is a large actual spot desirable?

A

to dissipate the heat of large exposures

146
Q

why is a target angle of at least 12 degrees desirable?

A
  • it will produce a radiation field that will cover a 14 x 17” IR at a distance of 40”
147
Q

define anode heel effect

A
  • uneven distribution of radiation intensity in the x-ray beam
  • Because of the slanted face of the target, some x-rays will have to pass through more target material than others, depending on their direction.
    *Variation in radiation intensity across the length of the radiation field
    *Greater radiation intensity toward the cathode end of the field
    *Only significant when using the whole beam (14- × 17-inch IR at 40 inches or full spine at 72 inches)
    *Place thinner portion of body part toward anode end of tube
148
Q

what examinations are used when applying the anode heel effect?

A
  • femur
  • thoracic spine
  • chest
  • lumbar spine
  • abdomen
149
Q

how should you place the patient when dealing with the anode heel effect?

A

place the patient so that the thinnest portion of the anatomy to be radiographed is toward the anode end of the tube

150
Q

what happens if the anode heel effect is not used correctly?

A

the thinner portions of the anatomy appear too dark on the IR and the thicker portions will be too light.

151
Q

what does kVp control?

A
  • penetration
  • contrast
  • quality
152
Q

what body part will require a high kVp?

A

larger and denser body parts

153
Q

what body parts will require a low kVp?

A

small or low-density body parts

154
Q

high kVp creates ___ contrast

A

low
- more shades of gray

155
Q

low kVp creates ____ contrast

A

high
- low shades of gray (black and white)

156
Q

what does mA control?

A
  • volume
  • quantity
  • rate of exposure
  • density
157
Q

define mA

A

measure of the rate of current flow across the x-ray tube (number of electrons)

158
Q

when mA is increased-

A
  • the filament heat is increased
  • more electrons are made
  • more x-rays are produced
159
Q

when mA is decreased-

A
  • the filament heat is decreased
  • less electrons are made
  • less x-rays are produced
160
Q

The density in the radiographic image is controlled by the-

A

mAs
- mA x sec.

161
Q

what is the relationship between mA and x-ray prodcution?

A
  • if mA is doubled, x-rays are doubled
  • if mA is halved, x-rays are reduced by 50%
162
Q

define exposure time

A
  • length of time that the x-rays are turned on
  • duration of the x-ray exposure
163
Q

what is the unit of measurement in exposure time?

A

seconds or milliseconds

164
Q

what is the relationship between exposure time and x-ray production?

A
  • if exposure time is doubled, x-rays are doubled
  • if exposure time is halved, x-rays are reduced by 50%
165
Q

define milliamperage-seconds (mAs)

A

the unit used to measure the total quantity of electrons involved in an exposure

166
Q

what is the formula for mAs?

A

mA x time (sec.) = mAs

167
Q

define x-ray beam filtration

A

*Filter material placed between the tube housing port and the patient removes the long-wavelength radiation from the primary beam.
*Because this radiation does not have sufficient energy to penetrate the patient, the cassette, and the table, it does not contribute to the image.
*Filtration lowers patient dose significantly.
*Filtration decreases the average wavelength of the x-ray beam.

168
Q

define filtration

A

the process of removing the long-wavelength photons from the x-ray beam

169
Q

what is the primary purpose of filtration?

A

to reduce patient dose

170
Q

what material is commonly used to filter out long wavelenghts?

A

aluminum

171
Q

define added filtration

A

added aluminum
- One or more aluminum plates installed between the tube port and the collimator

172
Q

define inherited filtration

A
  • filtration provided by the glass of the tube and the surrounding oil
  • “built in”
173
Q

define total filtration

A

equal to the inherent filtration plus the added filtration

174
Q

x-ray equipment operating at 70 kVp is required to have a total filtration of

A

at least 2.5 mm of Al equivalency at the source

175
Q

define induction motor

A
  • stator - current flow in it causes it to develop a magnetic field
  • rotor - induced magnetic field causes rotor to rotate
176
Q

what interaction makes up majority of the x-ray beam?

A

bremsstrahlung

177
Q

a characteristic interaction needs a minimum of ____ kVp to be produced

A

70

178
Q

what are factors of soft x-rays?

A
  • low kVp
  • low frequency
  • long wavelength
  • low energy
  • slight penetration
179
Q

what are the factors of hard x-rays?

A
  • high kVp
  • high frequency
  • short wavelength
  • high energy
  • complete penetration
180
Q

what are the three sections or subcircuits in the x-ray circuit?

A
  • low-voltage circuit (primary)
  • high-voltage circuit (secondary)
  • filament circuit
181
Q

what is the purpose of the low voltage/primary circuit?

A

supplies low voltage for operation of control console and for the variation of kVp

182
Q

what is the function of the AC power supply?

A

it’s wired into the building, providing electric power from the local power company
- converts standard AC power supply from the wall outlet into the high voltage necessary for x-ray production
- to produce the high voltages needed to accelerate electrons toward the anode in the X-ray tube

183
Q

what is the function of the main switch

A
  • controls the power to the control console
  • primary on/off switch
184
Q

what is the function of the voltage composer?

A
  • stabilizing and monitoring incoming voltage
  • measures the incoming electrical voltage from the power source and automatically adjusts it to maintain a stable, precise voltage (typically 220 volts) needed for proper X-ray generation, ensuring consistent image quality regardless of fluctuations in the power sup
185
Q

what is the function of the autotransformer?

A
  • provides the means for kVp selection
  • provides compensation for fluctuations in the incoming line voltage
  • supplies power to other parts of the x-ray circuit
  • controlling and adjusting the voltage supplied to the x-ray tube
  • works by self-induction
  • determines the voltage applied to the tube for x-ray production
186
Q

what is the primary function of the autotransformer?

A

to vary the voltage to the primary side of the step-up transformer

187
Q

what is the function of the kVp selector?

A
  • controls the kVp
  • controls how much voltage is set out to the rest of the primary circuit
188
Q

what is the function of the exposure switch?

A
  • closes the circuit
  • allows electric current to flow through the primary side of the step-up transformer
  • current is induced to flow through the secondary side of the transformer, creating voltage
  • acts as the start button to generate x-rays
189
Q

what is the function of the exposure timer?

A
  • device that terminates the exposure and is set by the operator on the control console.
  • controls the duration of the x-ray exposure
  • the time it takes the disk to move from the on switch to the off switch.
190
Q

what are the functions of the circuit breakers?

A

to protect against short circuits and electric shocks

191
Q

what is the function of the step up transformer?

A

used to increase the voltage from the autotransformer to the kilovoltage necessary for x-ray production.
- the dividing line between the primary and secondary circuit
- primary coil is in the primary circuit
- secondary coil is in the secondary circuit

192
Q

what is the function of the secondary circuit?

A

supplies high voltage to accelerate electrons for x-ray production

193
Q

what is the function of the secondary coil of the step-up transformer?

A
  • high voltage
  • converts volts into kilovolts
194
Q

what is the function of the milliampere meter?

A

monitors the x-ray tube current

195
Q

what is the function of a rectifier?

A
  • changes alternating current into direct current
  • changing the current to flow in one direction
196
Q

what is the function of the x-ray tube in the circuit?

A

produce x-ray photons

197
Q

what is the function of the filament circuit?

A
  • to supply a low current to heat the x-ray tube filament for thermionic emission of electrons
  • supplies and controls heat needed for thermionic emission
  • supplies electrons through step-down transformers
198
Q

when is the filament circuit activated?

A

any time the operator adjusts the mA on the generator

199
Q

what is the function of the mA selector/rheostat?

A
  • controls amperage
  • controls the amount of current flowing through the filament circuit of the x-ray tube
  • adjusting the milliamperage
  • controls filament temperature and the rate at which electrons are boiled off of the filament.
200
Q

what is the function of the step-down transformer?

A
  • increases current and decreases voltage
201
Q

what are the different types of rectifiers?

A
  • half-wave
  • full-wave
202
Q

define full-wave rectifier

A
  • rather than the negative impulses being eliminated, the negative impulses become positive impulses
  • negative impulses are “redirected” so that it all flows in one direction, leaving no gap during the waves
  • uses the entire electric cycle
  • all impulses flow in one direction
  • occurs when using 4 diodes
203
Q

what is an advantage if a full-wave rectifier?

A

the exposure time can be cut in half because of the doubling in x-ray output compared with half-wave rectification.

204
Q

define half-wave rectifier

A
  • eliminates the negative impulse of the electric cycle
  • gap remains between each wave
205
Q

what is the impulse rate of a full-wave?

A

120 impulses/sec.

206
Q

define diode

A

an electronic device that permits current to flow in one direction only

207
Q

how many diodes are used in half-wave rectification?

A

2

208
Q

what is the impulse rate of a half-wave rectification?

A

60 impulses/sec.

209
Q

how many diodes are used un full-wave rectification?

A

4

210
Q

what are the different type of generators?

A
  • single-phase
  • three-phase
  • high frequency
211
Q

define single phase

A
  • pulsating current that alternates from positive to negative during each electric cycle
  • produces a pulsating x-ray beam
  • lowest power and most basic
212
Q

single phase x-ray generators are powered by-

A

a single source of AC current

213
Q

define x-ray generators

A

converts the mechanical (KE) energy of the rotor to electrical energy

214
Q

define three-phase generator

A
  • more constant and efficient voltage source is provided by a three-phase power supply.
215
Q

define ripple

A
  • fluctuation of voltage

:] (100 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions