IEM Flashcards
(93 cards)
1
Q
Is the study of electric charges in static form
A
ELECTROSTATIC
2
Q
the property of subatomic particles that causes it to experience a force when placed in an electric and magnetic field
A
Electric Charge
3
Q
positively charge ions result from the loss of electrons and are called
A
cations
4
Q
Negatively charge ions result from the gain of electrons and are called
A
anions
5
Q
Electrification can be created by the following
A
Contact, Friction, and Induction
6
Q
a connection that causes the flow electrons
A
Contact
7
Q
buildup of electron caused by rubbing object together.
A
Friction
8
Q
using the electric field of a charged object to confer a charge on an uncharged object
A
induction
9
Q
An object is said to be _____ if it has too few or too many electrons
A
Electrified
10
Q
behaves as a huge reservoir for stray electric charges.
A
Earth (electric Ground)
11
Q
What are the electro static law?
A
Like charges attract, unlike charges repel. coulomb’s law, electric distribution, electrified charge distribution
12
Q
The fundamental unit of electrical charge is the
A
Coulomb
13
Q
1C=
A
6.3x10^18
14
Q
has the ability to the work when this energy is released
A
Electric Potential
15
Q
Electric potential is sometimes termed
A
Electromotive force or Voltage
16
Q
the study of charges in motion
A
Electrodynamics
17
Q
FOUR ELECTRICAL STATE OF MATTER
A
Conductors, Insulator, semiconductor, superconductor
18
Q
matter through which electrons flow easily; copper, aluminum, water
A
conductor
19
Q
matter that inhibits the flow of electrons ;glass, clay, earth like material.
A
Insulator
20
Q
matter that under some conditions behaves as an insulators and under other conditions act as a conduction ;Silicon and germanium
A
semi conductor
21
Q
Is the property of limited resistance to electron flow below critical temperature
A
Superconductor
22
Q
When the resistance is controlled and the electron flow over a closed path, the result is
A
Electric circuit
23
Q
Electric current are measured in
A
Ampere
24
Q
Electric potential is measured in
A
Volt
25
states that the voltage across the total circuit or any portion of the current is equal to the current times the resistance
OHMS law
26
The opposition to the flow of an electric current, producing heat.
resistance
27
What Influences Resistance?
material of wire, thickness, lenght, and temperature
28
allows electron to flow in one direction
diode
29
provides electric potential
battery
30
momentarily stores electric charge
capacitor
31
increases or decreases voltage by fixed amount (AC only)
Transformer
32
Comprises a path along which the whole current flows through each component
Series circuit
33
here are several branching paths to the components.
Parallel circuit
34
Electrons flowing in one direction along the conductor
Where electrons flow in the same direction in a wire.
Direct current
35
Current in which electrons oscillates back and forth
electrons flow in different directions in a wire
Alternating Current (AC)
36
Measured in Watts (W)
Power
37
The word magnetism comes from the name of that amount village
Magnesia
38
Magnetite is a
magnetic oxide of iron
39
is the properties and interactions of magnets
Magnetism
40
best example is the earth itself, because it spins on an axis.
Natural Magnet
41
available in many sizes and shapes but principally as bar or horseshoe-shaped magnets, usually made of iron.(e.g. compass)
Artificially produced permanent magnets
42
consist of a wire wrapped around an iron core
Electromagnets
43
cannot be magnetized
they cannot be artificially magnetized, and they are not attracted to a magnet
Diamagnetic
44
Materials lie somewhere between ferromagnetic and non-magnetic.
they are slightly attracted to a magnetic field
Paramagnetic
45
can be easily magnetized
strongly attracted by a magnet and can be usually be permanently magnetized by exposure to a magnetic field
Ferromagnetic
46
Every magnet no matter how small has two poles, north pole and south pole, equivalent to positive and negative electrostatic charges
Magnetic Dipoles
47
Imaginary magnetic field lines are called magnetic lines of induction and the density of the lines is proportional to the intensity of the magnetic field
Magnetic Induction
48
This magnetic force is similar to electrostatic and gravitational forces that also are inversely proportional to the square of the distance between the objects under consideration. If the distance between two bar magnets is halved, the magnetic force increases by four times
Magnetic Force
49
The SI unit of magnetic field strength is the
Tesla or gauss
50
1 tesla is equivalent to how many gauss?
10,000 Gauss
51
The Earth’s magnetic field is proximately ___ at the poles and ___ at the equator
50 and 100
52
Magnetism produced by electricity called
ELECTROMAGNETISM
53
who discovered animal electricity
Luigi Galvani
54
discovered voltaic pile
Alessandro Volta
55
Each zinc-copper sandwich is called
cell of a battery
56
A coil of wire is called
selonoid
57
says that an electric current will be induced to flow in a circuit if some part of that circuit is in a changing magnetic field.
Faraday's law
58
The magnitude of the induced current depends on the four factors:
strength of magnetic field, velocity of magnetic field, angle of the conductor, number of turns in conductor
59
Converts mechanical to electrical energy
electric generator
60
Converts electrical to mechanical energy
electric motor
61
operates on the principle of mutual induction, it will only operate with a changing electric current (AC)
Transformer
62
is a square doughnut of magnetic material
closed- core transformer
63
consists of an iron core with only one winding of wire
autotransformer
64
most used transformer
shell type transformer
65
Changes AC to DC
Rectifier
66
what are the 3 component of xray units
operating console, high voltage generator, xray tube
67
is the most familiar to the radiographer, this apparatus allows the radiographer to control xray tube
control panel
68
basic controls of control panel
on/off control, KVp selection, mAs Selection, table or wall unit activation, exposure switch, line compensation, mA meter, AEC or phototiming
69
incorporates a meter to measure the voltage
provided to the x-ray machine and a control to adjust that voltage to
precisely 220 volts.
Line compensation
70
Some older x-ray operating consoles have labelled major kVp and
minor kVp, by selecting a combination of these controls the
radiographer can provide precisely the required kVp.
kVp
KVp adjustment
71
Determines the penetrating quality of the x-ray beam
KVp
72
it allows the voltage to be monitored before an exposure
prereading KVp Meter
73
The number of electrons emitted by the filament is determined by
the temperature of the filament.
The filament temperature is controlled by the filament current,
which is measured in Amperes (A)
mA Control
74
Filament normally operates at the current between
3-6 ampere
75
cause the x-ray tube to emit for a specific time as
determined by the radiographer or by an automatic exposure
control
exposure timer
76
are very simple devices used only in some portable and dental units.
The __________ operates by clockwork.
mechanical timer
77
A special type of electronic motor, known as _______,
is a precision device designed to drive a shaft at precisely 60
revolutions per seconds (rps)
synchronous timer
78
are the most sophisticated, most complicated, and
most accurate of the x-ray exposure timers
Electronic timer
79
Most x-ray apparatus is designed for accurate control of tube current and exposure time. The product of mA and time (mAs) determines
the number of x-ray emitted
mAs Timer
80
automatically stops when enough exposure is emitted
AEC
81
it is used to evaluate time xray are produced, it is important in controlling xray emission/exposure
evaluation timer
82
2 types of evaluation timer
spinning top and oscillator
83
is responsible for converting the low voltage from
the electric power company into a kilo-voltage of
the proper waveform.
high voltage generator
84
This is a step-up transformer (the secondary voltage is
higher than the primary voltage
High voltage transformer
85
The ratio of the number of secondary windings to the
number of primary windings is called
turn ratio
86
is the process of converting alternating voltage into direct voltage and therefore alternating
current into direct current
rectification
87
Represent a condition in which the voltage is not allowed to swing
negatively during the negatively half of its cycle
half wave rectification
88
rectified circuit the negative half cycle corresponding
to the inverse voltage is reversed so that a positive voltage is always
directed across the x-ray tube.
full wave rectification
89
results in pulsating x-ray beam. This is caused
by the alternating swing in voltage from zero to maximum potential
120 times each second under full wave rectification
single phase power
90
multiple voltage waveforms are
superimposed on one another, which result in a waveform that
maintains a nearly constant high voltage.
three phase power
91
The newest development in high-voltage generator design uses a
high-frequency circuit
high frequency generator
92
is the variation in peak voltage waveform
voltage ripple
93
The parts of an x-ray unit are identified by their power rating in kW
power rating
