physics final Flashcards
(97 cards)
1
Q
Unit of mass
A
Kg
2
Q
what does the period in periodic table represent ?
A
Principle quantum number
3
Q
isotope have ___ Mass numbers and ____ atomic number
A
Different, same
4
Q
Atomic number is number of what contained in the nucleus?
A
Protons
5
Q
according to rule of octets energy has
A
Valence shell is chemically, and 8 in the outer shell
6
Q
what is energy?
A
The ability to do work
7
Q
what is radiation
A
Energy transfers through matter
8
Q
what happens to binding energy as electrons get closer to the nucleus
A
It Tightens (tight bond)
9
Q
How are shells currently identified
A
numerical principal quantum number or K,L,M, N, O, P
10
Q
What is electromagnetic energy produced by?
A
Acceleration of a charge
11
Q
The resistance in a wire decreases as it
A
Diameter increases
12
Q
The flow of electrons at a rate of 6.24x10 represents what
A
1 AMP
13
Q
Ohms law is mathematically described as what?
A
R=v/I
14
Q
What is electric potential measured as?
A
Volts
15
Q
When atomic valence and conductive bands overlap, what happens ?
A
electric easily flows
16
Q
if a distance between 2 electrical charges is doubled, the force between them is?
A
Decreased 1/4 of its original intensity
17
Q
An ampere is
A
coloumb/sec
18
Q
unit of electrical power is ?
A
Watts
19
Q
process of electrons being emitted from the heated Metallic surfaces
A
Thermonics emissions
20
Q
Magnetic field is produced what ?
A
Electric charge in motion
21
Q
Generator is a device that convert what?
A
Mechanical to electrical
22
Q
A motor is a device that converts
A
Electrical to mechanical
23
Q
Transfer with more 2nd winding than primary?
A
Has greater secondary voltage
24
Q
American household generators operate at what?
A
60Hz
25
stators consist of
Electromagnets
26
All of the following are true of transformer except?
Work most efficient on pulsating DC
27
Turns ratio of transfer is determined by what ?
Number of windings
28
Function of the cathode is to produce
Thermionic cloud
29
Filament are chosen primary for there what ?
High melting point
30
Driving the thermonic cloud from the cathode to anode requires
High Voltage
31
what kind of charge does a focusing cup have ?
Negative
32
x ray photons production occurs at what
Anode
33
Tungesten is a choice primarily because of
High atomic number
34
Area of a focal projected towards the patient is what?
Effective focal spot
35
Actual focal spot is controlled by
length of the filament
36
Most common diagnostic x ray tube anode angle
12 degrees
37
Protective housing controls scatter and leakage through?
Absorption
38
where is the stator located
outside the glass envelope
39
Select true statement regarding digital imaging.
Brightness on review monitor is not related to exposure.
40
What is the primary factor controlling quantity in digital imaging?
mAs
41
What is the relationship between mA and exposure?
Directly proportional
42
An increase in kVp by 15% will cause an approximate what to the exposure?
Double
43
When a ray passes through matter, it goes through a process called what?
Attenuation
44
Which shell possesses the highest binding energy?
K Shell or inner shell
45
Which energy level electron possesses the highest total energy?
N
46
When ray photons interact with matter and change direction, it is called what?
Scatter
47
During photoelectric interaction, what shell electron is ejected?
Inner
48
During fluoroscopy, what is the primary source of exposure?
Compton
49
In the human body, what is the predominant interaction of x-rays?
Compton
50
In an effort to decrease mAs of an exposure and increase kVp, what type of effect will that have on your IR?
Decreased kVp results in more scatter
51
In radiology, radiographic image is a principle present due to what interaction?
Photoelectric
52
You can best minimize scatter by restricting the beam. True or False?
True
53
Image quality is improved when scatter is reduced reaching the IR. True or False?
True
54
Bone absorbs more radiation and produces more scatter. True or False?
False
55
Which give you the highest IR EXPOSURE ?
Milliseconds
56
What is penumbra?
Penumbra is a geometric unsharpness around the periphery of an image
## Footnote
This concept is important in radiography for understanding image quality.
57
How can a radiographer best reduce the amount of scatter?
By using a radiographic grid
## Footnote
Radiographic grids are designed to absorb scatter radiation, improving image contrast.
58
As kVP increases, what happens to the percentage of x-ray interactions?
It will increase primarily through Compton interactions
## Footnote
Compton scattering is a significant interaction in diagnostic radiology.
59
What happens as the volume of radiated tissue increases?
You will get an increase in scatter
## Footnote
Larger volumes of tissue result in more scatter radiation, affecting image quality.
60
Which of the following is not a beam restricting device?
Beam filter
## Footnote
Beam restrictors are used to limit the size of the x-ray beam, while filters modify beam quality.
61
What should you do if you collimate from 14x17 to 8x10?
Increase mAs to maintain exposure
## Footnote
Changing the collimation affects the amount of radiation reaching the image receptor.
62
Where is the Stator located?
Outside the glass envelope.
63
In the x-ray circuit, where is the mA control found?
Between the incoming line and step-down transformer.
64
All of the following are in your control except what?
Rotor speed.
65
What is the diagnostic ray exposure range approximately?
All of the above.
66
When using AEC at 80 kVp, what must the backup time not exceed?
600 mAs.
67
All of the following are ray tube support systems except what?
Fluoroscopic tower.
68
What are high frequency generators known for?
All of the above.
69
What may happen when radiographing thin body parts using AEC?
May produce an inconsistent image due to AEC errors.
70
Which component controls the length of the x-ray exposure?
Timer.
71
The single function of AEC is to eliminate the need to set what?
Time.
72
When using an AEC, what do you lose control of?
mAs.
73
When AEC is used for hip imaging, which chamber is used?
Center.
74
For a chest x-ray, which chambers are used?
Left and right.
75
What does US law require generators to terminate at?
600 mAs.
76
What were early versions of AEC referred to as?
Photo-timers.
77
Brems occurs when an incident electron interacts?
Force field around the nucleus
## Footnote
Bremsstrahlung radiation occurs when an electron is deflected by the electric field of a nucleus, resulting in the emission of x-rays.
78
During characteristic interaction, dropping of a higher electron state results in lower what?
Photon of electromagnetic energy
## Footnote
This process emits a photon as an electron transitions to a lower energy state.
79
At the end of the characteristic cascade, what shell is missing?
Outer
## Footnote
The characteristic cascade occurs as electrons fill vacancies in inner shells, leading to the removal of outer shell electrons.
80
Max number k shell can hold how many electrons?
2
## Footnote
The k shell, being the closest to the nucleus, has a maximum capacity of 2 electrons.
81
X-rays are characterized as?
Both b and C
X-rays are electromagnetic waves of high frequency and short wavelengths.
82
Electrons going from cathode to anode are called what?
Incident
## Footnote
These electrons are responsible for the generation of x-rays when they collide with the anode.
83
Which is not one of the 3 things required for x-ray production?
Photostimulable phosphor
## Footnote
The three essentials for x-ray production are a source of electrons, a means to accelerate them, and a target material.
84
Filtration is the process of eliminating what?
Low energy x-ray photons
## Footnote
Filtration helps to improve the quality of the x-ray beam by removing less penetrating photons.
85
Beam filtration does what to patient dose?
Decreases it
## Footnote
By filtering out low-energy photons, patient exposure to unnecessary radiation is reduced.
86
Most common x-ray beam filter material is what?
Aluminium
## Footnote
Aluminium is widely used due to its effective filtration properties and compatibility with x-ray equipment.
87
All filtration can be expressed by what?
Aluminium
## Footnote
The effectiveness of filtration is often quantified in terms of equivalent aluminium thickness.
88
Amount of materials that will reduce the intensity to half of its original layer is what?
Half value layer
## Footnote
The half value layer (HVL) is a measure of the thickness of material needed to reduce the intensity of radiation by half.
89
Most inherent filtration of ray equipment comes from where?
Window of glass envelope
## Footnote
The glass envelope of the x-ray tube provides some inherent filtration of the beam.
90
Collimator device is considered part of what?
Added
## Footnote
Collimators are devices that restrict the size and shape of the x-ray beam, contributing to added filtration.
91
Built up of tungsten of age tube adds to what filtration?
Inherent
## Footnote
The tungsten in the x-ray tube contributes to the inherent filtration by absorbing low-energy photons.
92
Calculate mAs formulas for some of the questions
mAs maintenance law
## Footnote
The mAs (milliampere-seconds) is a product of current and exposure time, crucial for maintaining consistent x-ray output.
93
Factors that affect ray emissions under radiographers control are what factors?
Prime
## Footnote
These prime factors include mA (milliamperes), time, and kVp (kilovolt peak).
94
Factors that affect quantity are?
Both a and b (mA and time = mAs)
## Footnote
Both milliamperage and exposure time directly influence the quantity of x-rays produced.
95
Factor that affect quantity
Absorption
96
When following up an abdomen image with patient who recently had contrast study what is best done?
Disable AEC and use manual technique
97
. Transfer of energy to outer shell electrons results in the emission fo what?
a. Infrared
