Ch. 4 The X-Ray Circuit Flashcards
the amount of current flowing with an electric potential of 1 volt in a circuit with a resistance of 1 ohm
ampere
conductor fashioned into a coil
solenoid
what is the strength of magnetic field measured in
tesla (T)
not attracted to magnetic fields at all
nonmagnetic - glass, wood, plastic
x-ray production is simply achieved through what
manipulation of electricity
a process of connecting the electrical device to the earth via a conductor; protective measure
grounding
devices that inhibits the flow of electrons, thereby precisely regulating the flow of electricity through that part of the circuit where it is placed
resistor
the electric resistance equal to the resistance between two points along a conductor that produces a current of 1 ampere when a potential difference of 1 volt is applied
ohm
what is ripple of three phase, high frequency
<1%
unit of measure for electric potential
volt
current that flows in only 1 direction
direct current (DC)
the study of electric charges in motion
electrodynamics
the mA selector is known as a what
rheostat; variable resistor
what circuit section is the exposure timer located in
primary circuit
device the produces electrons through a chemical reaction, stores an electric charge for the long term, and provides an electric potential
battery
formula for total resistance in a parallel cirucit
1/Rt=1/R1+1/R2+1/R3 etc.
the low voltage/filament circuit works on how many volts
8-12 v
devices used to increase or decrease voltage (or current) through electromagnetic induction
transformer
how much leakage flux does the shell-core transformer have
5%
shell-core transformer is how efficient
95%
transformer that decreases voltage
step-down transformer
1 coulomb flowing by a given point in 1 second
ampere
where do flux travel from north pole to the south pole
outside the magnet
circuit in which circuit elements “bridge” or branch across a conductor
parallel circuit
occurs when objects gain either a net positive or a net negative charge in electrostatics
electrification
the study of stationary electric charges
electrostatics
occurs as a result of the interaction of the electric fields around two objects that are not in contact with each other
induction
property of an element in a circuit that resists or impedes the flow of electricity
resistance
formula for total voltage in a parallel circuit
Vt=ItxRt; voltage is equal throughout circuit
what is the equation for power
P=IV
formula for total resistance in a series circuit
Rt=R1+R2+R3 etc
the ability to do work because of a separation of charges
electric potential
material used extensively in the creation of magnets and magnetic fields
iron
weakly repelled by magnetic fields
diamagnetic - water, gold, mercury
1 coulomb is equal to an electric charge of how many electrons
6.25x10^18 electrons
adjusts incoming voltage in primary circuit to be exactly 220v
line voltage compensator
where do the lines of flux travel from south pole to north pole
inside the magnet
temporarily stores an electric charge
capacitor
transformer that increases voltage
step-up transformer
the large electron beam has how much resistance compared with the small beam
less resistance
formula for total voltage in a series circuit
Vt=ItxRt; Vt=V1+V2+V3 etc
unit of measure for current
ampere
the potential difference that will maintain a current of 1 ampere in a circuit with a resistance of 1 ohm
volt
what temperature makes for better conducting of electricity or current
colder/lower
one-way valve device that allows electrons to flow in one direction only
diode
transformer law for voltage
direct - Vs/Vp=Ts/Tp
emergency devices that break or open the circuit if there is a sudden surge of electricity to the circuit or device
protective devices - fuses, circuit breakers
3 ways objects may be electrified
- friction
- contact
- induction
weakly attracted to magnetic fields
paramagnetic - platinum, gadolinium, aluminum
radiolucent device placed between the patient and the image receptor; x-rays interact with chamber and its atoms are ionized creating an electric charge
ionization chamber
devices that convert electric energy to mechanical energy through electromagnetic induction
electric motors
relation of voltage to current in a transformer
inverse - Is/Ip=Vp/Vs
most common type of transformer
shell-core
what is the ripple of three phase, 12 pulse
4%
a section of special wire usually encased in glass that quickly melts if the current flow rises excessively
fuse
lines of flux in opposite directions do what
attract
devices that convert some form of mechanical energy into electric energy
electric generator
formula for current in a series circuit
equal throughout
a device that can increase or decrease voltage by a predetermined amount
transformer
formula for total current in a parallel circuit
It=I1+I2+I3 etc
strongly attracted to magnetic materials
ferromagnetic - iron, cobalt, nickel
when 4 rectifiers are used, what type of rectification is achieved
full-wave
an adjustable or variable form of resistor
rheostat
for three phase, 12 pulse what percent of kVp selected translates to x-ray production
96.5%-100%
for three phase, 6 pulse what percent of kVp selected translates to x-ray production
87%-100%
lines of flux in the same direction do what
repel
what type of induction does the autotransformer use
self-induction
the induction of electricity in a secondary coil by a moving magnetic field
mutual induction
a device that opens a circuit (breaks pathway)
switch
current that changes direction in cycles as the electric potential of the source changes
alternating current (AC)
transformer law for current
inverse - Is/Ip=Tp/Ts
the potential difference (volt) across the total circuit or any part of that circuit is equal to the current (ampere) multiplied by the resistance (ohm); V=IR
ohms law
the ability of a material to attract iron, cobalt, or nickel
magnetism
what is resistance measured in
ohms
what is ohm’s law
V=IR
what are electric charges measured in
coulombs
circuit in which circuit elements are wired along a single conductor
series circuit
an induced current flows in a direction that opposes the action that induced it
lenz’s law
most widely used exposure timer
electronic timer
equal to the amount of work (joules) that can be done per unit of charge
volt; volt=joules/coulombs
what is the autotransformer controlled by
kVp selector
an expression of the flow of electrons in a conductor
current
what is the ripple of three phase, 6 pulse
13%
phenomenon that moving a conductor through a magnetic field induces an electric current in that conductor
electromagnetic induction
