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Which Scientist discovered that a magnetic field always surrounds a conductor in which an electric current is flowing?
Hans Oersted
Michael Faraday
The Magnetic Field will only exist around a wire while the electric current _________ flowing.
is
is not
No Electric Current = No Magnetic Field
The Magnetic Field collapses when the current is __________________.
terminated
flowing
If the switch is ____________, there will be no current.
open
closed
If the switch is _____________, there will be a current flowing.
Magnetic Field lines form ______________ around the wire.
Circles
Extra lines
The closer to the wire, the _____________ the Magnetic Field.
stronger
weaker
If the wire is a loop, the Magnetic Field lines are concentrated (strongest) on the ____________ of the loop.
inside
outside
If you stack many loops together (coil) with an electric current flowing, the Magnetic Field ______________.
increases
decreases
A coil of wire with an electric current is a _______________.
Solenoid
Electromagnet
Ferromagnet
Step-up Transformer
The Magnetic Field can be intensified further by wrapping a coil of wire around a _________________ material.
ferromagnetic
diamagnetic
paramagnetic
non-magnetic
The majority of the magnetic field lines are ____________ the coil.
"The Magnetic Field can be intensified further by wrapping a coil of wire around a ferromagnetic material (iron)". This is considered _____________________.
Artificially
Naturally
A(n) ________________ is a current-carrying coil of wire wrapped around an iron-core, which intensifies the Magnetic Field.
Natural Magnet
Artificial Magnet
A Solenoid can be used as a remote control magnet.
In Radiography, a _______________ is used as a tube stand lock and bucky tray lock.
Stator
Rotor
Transformer
When you open and close a switch an electric current starts and ______________.
stops
continues
What did Faraday want to prove?
That Oersted's experiment was true.
The opposite of Oersted's experiment.
Faraday concluded that an electric current _________ be induced by the presence of a magnet.
can
cannot
When a magnet is in motion, the intensity changes, an electric current is ________________.
produced
absent
The changing of the Magnetic Field to produce an electric current is _______________________.
Electromagnetic Induction
Heat
Step-Up Transformer
Step-Down Transformer
Electromagnetic Induction is AKA ______________________ law.
Oersted's
Faraday's
The basis of Faraday's Law was that ____________ Magnetic Field intensity induces an electric current.
varying
constant
The magnitude of the induced current depends on four factors. The strength of the magnetic field is one of them.
True
False
Select the following factors that induce the magnitude of the current:
The strength of the magnetic field
The velocity of the magnetic field as it moves past the conductor
The angle of the conductor to the magnetic field
The number of turns in the conductor
The rotating speed of the Anode target
Direct Current
Alternating Current
Electric Motors and Generators are NOT good examples of Oersted's and Faraday's Laws.
In Radiography, an electric induction motor is used to _____________________.
Rotate the Anode target
Turn the Cathode
Neither
Within the Electric motor, what is considered the "Fixed Electromagnetic's"?
The Electric Motor is a good example of __________________ Law(s).
Einstein's
Oersted's and Faraday's
Within the Electric Motor, what is considered "copper bars and iron core"?
stator
rotor
_______________________ is supplied to the AC induction motor.
In an AC induction motor the EXTERNAL Magnetic Field is supplied by an _________ number of fixed electromagnets called a stator.
odd
even
A ___________ is placed inside this arrangement of stators as the armature.
Anode
Coil
The AC current supplying one opposite pair of coils is ___________ phase with the current supplying the next pair of coils.
out of
in
In the production of diagnostic x-rays, it is necessary to ______________ the incoming line voltage of 110 or 220 into the kilovoltage range.
increase
decrease
A transformer does convert one energy to another.
Electric Potential AKA ____________________.
Voltage
Current
Flow of electrons
Current AKA ____________________.
Electric Potential
A Transformer transforms electric potential (voltage) and current (flow of electrons) into higher or lower intensity.
A transformer changes the intensity of alternating ________________ and _______________.
voltage, current
coils, voltage
current, coils
Primary coil, Secondary coil
Consider an electromagnet with a FERROMAGNETIC core bent around so that it forms a continuous loop.
Secondary Coil
Primary Coil
Transformers. There are no end surfaces from which the field lines can escape.
Transformers. The __________________ tends to be confined to the loop of the magnetic core material.
Magnetic Field
Cathode
Another coil wound around the other side of the loop of core material.
Will the Magnetic Field produced by the PRIMARY coil pass through the center of the SECONDARY coil?
Yes
No
A good _____________ is created between the magnetic field produced by the primary coil and the secondary coil.
coupling
current
voltage
The PRIMARY (input) coil is supplied with ____________________. *Establishing a magnetic field around the coil.
Which coil is responsible for establishing a magnetic field around the coil?
Primary (input) coil
Secondary (output) coil
The Primary Magnetic Field will cut the __________________ coil and induce an Electromagnetic Field (EMF) and alternating current (AC).
Secondary (output)
Primary (input)
A changing current in the primary coil induces a changing current in the secondary coil.
A Transformer will operate only with changing current, ________________________.
The transformer is used to change the magnitude of _____________ and current in an AC circuit.
primary coil (input)
secondary coil (output)
efficiency
The change in voltage is _____________ proportional to the ratio of number of turns (winding's) of the secondary coil (Ns) to the number of turns in the primary coil (Np).
Directly
Inversely
Voltage is induced in each of the turns of the _________________ coil.
Turns Ratio:
Ns/Np
Np/Ns
Secondary coil turns are 10 times more than the Primary coil turns.
The turns ratio is part of the _________________ Law Formula.
Faraday
Oersted
Einstein
What is the Transformer Law?
Vs/Vp = Ns/Np
Vp/Vs = Np/Ns
Vp/Vs = Ns/Np
Vs/Vp = Np/Ns
A step-up transformer ____________ the potential difference.
A step-up transformer will have a turn ratio greater than ___________.
one
two
ten
five
Does a step-up transformer have more turns in the secondary coil or primary coil?
Secondary
Primary
Step-Up transformer: _________________ EMF (voltage)
Increases
Decreases
Step-Up transformer: ________________ current
Step-Up transformer: _________________ is doubled, ______________ is halved.
Voltage, Current
Current, Voltage
A Step-Down transformer _________________ the potential difference.
A Step-Down transformer will have a turn ratio of less than ___________.
With the Step-Down transformer there are more turns in the __________________ coil than the _________________ coil.
Primary, Secondary
Secondary, Primary
Step-Down Transformer: ________________ EMF (voltage)
Step-Down Transformer: __________________ current
Step-Down Transformer: _____________________ is halved, _________________ doubles
In a Step-Up transformer, the current on the secondary side is ______________ than the current on the primary side.
larger
smaller
In a Step-Down transformer, the secondary current is _____________ than the primary current.
According to ______________'s Law, Voltage and Current are inversely proportional.
Ohm
The # of transformer turns and induced amperage must also be inversely proportional.
The Effect of Transformer Law on Current may be written as:
Is/Ip = Np/Ns
Ip/Is = Np/Ns
Ip/Is = Ns/Np
Is/Ip = Ns/Np
A _________________-core transformer consists of heavily insulated coils wound around a square or circular iron core.
Open
Closed
The ___________________ core is not a single piece but rather built up of laminated layers of iron.
Ferromagnetic
Diamagnetic
Non-magnetic
Paramagnetic
Laminated layers help reduce ______________ loses, resulting in greater efficiency.
energy
magnitude
An AUTO-TRANSFORMER consists of an iron core with ____________ winding wire around it.
The single wire on the AUTO-TRANSFORMER acts as __________________.
both the primary and secondary winding.
the primary winding
the secondary winding
neither
Which transformer operates using self-induction?
AutoTransformer
Autotransformer: Connections are made at ___________ points on the coil for both the primary and secondary sides.
same
different
Autotransformers are usually larger than regular transformers.
Autotransformers are generally used when a ___________ step-up or step-down in voltage is required.
small
large
A _______________ transformer consists of a laminated silicon steel core with two rectangular holes and a central section.
shell-type
regular
auto
The insulated coils on a Shell-Type transformer are wound around the ________________ section of the core.
central (center)
top
bottom
Shell-Type Transformer: Insulated coils are wound around the central section of the core to __________ the distance magnetic flux has to travel between the two coils.
reduce
A Shell-Type Transformer reduces the distance the magnetic flux has to travel and therefore decreases the leakage flux.
Which transformer is the most currently used type of transformer?
Shell-Type
Regular
Auto
Which transformer is more efficient?
Shell-type
The effectiveness of _____________ induction is increased with Shell-type Transformer.
Mutual
Self
Transformers: There is a normal ____________ loss of power in the secondary circuit from heat production that occurs due to resistance.
5%-10%
10%-50%
1%-5%
15%-20%
An AutoTransformer is considered a(n) _____________ selector.
kVp
mA
s
A Step-Up transformer is AKA a _________-Voltage Transformer.
High
Low
A Step-Down Transformer is AKA a(n) ______________ Transformer.
Filament
Which Transformer increases the tube voltage to kV?
Step-Up
Step-Down
Which Transformer decreases tube current to mA?
Which Transformer reduces voltage?
Which Transformer increases the filament amperage for thermionic emission?