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WorksheetsRAD 230 - Week 2
Total questions: 72
Worksheet time: 12hrs 0mins
What are the three methods of electrification?
Induction
Diffusion
Contact
Friction
Excitation
If you run a comb through your hair, electrons are removed from the hair and deposited on the comb. The comb becomes electrified with too many negative charges. An electrified comb can pick up tiny pieces of paper as though the comb were a magnet. This is an example of ________________.
induction
electric ground
static electricity
potential
Electrostatic charge is measured in:
Amperes
Joules
Coulombs
Electron volts
Which of the following is true?
A neutron will repel a neutron.
A proton will repel a neutron.
An electron will repel a neutron.
An electron will attract an electron.
An electron will repel an electron.
What causes electrification?
An excess of neutrons
An excess of protons
Transfer of electrons
Transfer of neutrons
Transfer of protons
Increasing atomic number :
will decrease the energy of characteristic x-rays
does not affect the energy of characteristic x-rays
increases the energy of characteristic x-rays
results in radiolucent areas on x-ray imaging
What is unique about the autotransformer?
It has 2 coils - one on the primary side and one on the secondary side
It is a single coil of wire
It changes AC to DC
It adjusts the incoming voltage to exactly 220V
Where is the kVp meter?
Connected to the autotransformer
Connected to the anode on the secondary side of the x-ray circuit
Connected to the step-up transformer
Connected to the step down transformer
The x-ray tube has 2 electrodes: an anode and a cathode. Therefore, an x-ray tube is a(n):
electrode
diode
cathode
anode
ode to joy
True or false: The cathode is one of two electrodes in the x-ray tube diode.
True
False
Which of the following is an electric insulator?
Copper
Water
Nickel
Tungsten
Wood
Electrical current in the x-ray tube is expressed in:
mA
V
kVp
Ω
True or false: The filament transformer increases voltage.
True
False
If a filament transformer has a turns ratio of 0.05 and 400 mA is supplied to the primary side of the transformer, what will be the secondary current?
20
8000
1.25 x 10-4
8
What causes the anode heel effect?
The depth of the filaments within the focusing cup
Insufficient heating of the filament
X-ray absorption in the anode 'heel'
The space charge effect
Which of the following could be an angle of the target track of a rotating anode?
2
4
15
25
Increasing kVp results in:
increasing characteristic x-ray energy
decreasing characteristic x-ray energy
short scale contrast
decreased penetrability
True or false: Characteristic x-rays are characteristic of the target's Z number.
True
False
Tungsten is used as the target material in anode target tracks. Its electron binding energies are:
K - 69 keV
L - 12 keV
M - 3 keV
N - 0.5
Which of the following characteristic x-rays would be produced with operation at 70 kVp?
12 keV
57 keV
72 keV
81 keV
True or false: Electric energy can be converted into chemical energy by an x-ray imaging system.
True
False
True or false: Electric energy can be converted into electromagnetic energy by a battery.
True
False
True or False: Electric energy can be converted into mechanical energy by a battery.
True
False
True or False: Electric energy can be converted into nuclear energy in a nuclear reactor.
True
False
True or False: Electric energy can be converted into thermal energy by a lamp.
True
False
Laws of Electrostatics include which of the following?
Repulsion-Attraction: Like charges repel, unlike charges attract.
Charge Concentration: The greatest concentration of charge will be on the surface where the curvature is sharpest.
Magnetic Induction: The process of electrical fields acting on one another without contact.
Distribution: Charges reside on the external surfaces of conductors and equally throughout nonconductors.
What is the formula for Ohm's law?
V = IR
E = mc2
P = IV
Vs/Vp = Ns/Np
Resistance is measured in _______.
Joules
Newtons
Ohms
Teslas
The number of volts required to cause a current of 30 A in a circuit having a resistance of 10 Ω.
3000
3
300
30
1 Coulomb/second in a conductor =
1 Volt
1 Amp
1 Ohm
1 Brad
If a 100 W lightbulb is operated at 120 V, the current flowing through the bulb is approximately:
1.2 A
12,000 A
0.8 A
10 A
1 kW/h can also be expressed in:
Newtons
Volts
Joules
Amps
There are six basic types of magnetization: (1) diamagnetism, (2) ____________, (3) ferromagnetism, (4) antiferromagnetism, (5) ferrimagnetism, and (6) superparamagnetism.
electromagnetism
polar magnetism
induction magnetism
diploic magnetism
paramagnetism
As the distance between them increases, the force decreases by a factor of the square of the distance. This means that the force decreases rapidly as the distance between the magnets increases. This means that the force between magnetic poles of two magnets obeys:
The power law
The inverse square law
The force law
The electrostatic law
True or False: Autotransformers operate on the principle of Faraday's Law.
True
False
220 V is supplied to 750 primary turns of an autotransformer. What will be the output voltage across 150 secondary turns?
1,100 V
44 V
440 V
11,000 V
True or false: The filament transformer increases current.
True
False
X-ray tube current is usually expressed in mA, but it can also be expressed in:
Coulombs/second
kiloelectron volts
kilovoltage peak
rads
Rectifiers contain N-type and P-type electrodes which makes them:
a semiconductor
increase voltage
perfect to transform DC into AC
increase current
In self-rectification, the x-ray tube itself acts as a vacuum tube rectifier. The voltage ripple associated with self rectification is:
100%
12%
1%
15%
Select the three principal parts of an x-ray imaging system.
1-Rectifiers
2-Anode
3-Cathode
4-Operating console
5-X-ray tube
6-Filament
7-High-voltage generator
2, 3, and 5
2, 3, and 7
1, 2, and 3
4, 5, and 7
2, 6, and 7
An x-ray tube contains 2 electrodes: one cathode and one anode. This makes it a:
cathode
diode
anode
dipolar electrode
True or False: If saturation is achieved and the filament current is fixed, tube current will be variable.
True
False
The line-focus principle allows for:
reduced focal spot size
increased mA
increased x-ray intensity
increased heat capacity
Why is tungsten the optimal material for the target track of the anode? (Select all that apply)
High Z number
High rpm
High thermal heat conductivity
High thermionic emission
High melting point
If we increase our kVp - if all other factors remain the same - which of the following is true?
lower average beam energy
lower beam intensity
higher quantity of x-rays
Bremsstrahlung x-ray production remains unchanged
Which of the voltage waveforms pictured is associated with single-phase, full wave rectification?
A
B
C
D
E
Which of the voltage waveforms pictured is associated with single-phase, half wave rectification?
A
B
C
D
E
Which of the voltage waveforms pictured is associated with three-phase, six pulse generator power?
A
B
C
D
E
Which of the voltage waveforms pictured is associated with three-phase, twelve pulse generator power?
A
B
C
D
E
Which of the voltage waveforms pictured is associated with high-frequency generator power?
A
B
C
D
E
Which of the voltage waveforms pictured is associated with the most efficient x-ray production?
A
B
C
D
E
Which 2 of the voltage waveforms pictured is associated with the highest voltage ripple?
A
B
C
D
E
With which of the voltage waveforms pictured does the voltage supplied to the x-ray tube never decrease to less than 86% of the maximum value?
A
B
C
D
E
In the attached image, which letter corresponds to characteristic x-ray production in tungsten?
A
B
In the attached image, which letter corresponds to bremsstrahlung x-ray production?
A
B
In the attached image, if the kVp were increased, what would happen to the spectrum?
The amplitude would decrease and the peak would shift to the left
The amplitude would decrease and the peak would shift to the right
The amplitude would increase and the peak would shift to the right
A change in kVp will not affect the spectrum
In the attached image, if the mA were increased, what would happen to the spectrum?
The amplitude would decrease
The amplitude would decrease and the peak would shift to the left
The amplitude would increase
The amplitude would increase and the peak would shift to the right
In the attached image, what kVp energy is needed for the characteristic spike at 70 keV?
60 kVp
70 kVp
80 kVp
kVp does not affect characteristic x-ray production
Planck's constant x 3x108 m/s =
Jm
Jm2
J/m
J/s
What would have the greatest effect on low-energy photons in the x-ray emission spectrum?
mA
filtration
kVp
voltage waveform
In the attached image, what area corresponds to x-ray intensity?
The area under the emission spectrum
The amplitude of the characteristic x-ray spectrum
The energy range of the x-ray emission spectrum
The amplitude of the highest emission spectrum
True or False: Increasing mAs increases both bremsstrahlung and characteristic x-ray quantities.
True
False
X-rays that escape through the tube housing and that can contribute to patient dose and occupational dose are called:
leakage radiation
off-focus radiation
remnant radiation
the primary beam
When current is applied to the filament of the cathode, what is the process by which electrons are 'boiled off' for use in x-ray production?
thermionic effusion
thermionic diffusion
thermionic emission
nonionic emission
The external structure of the x-ray tube includes the support structure, the protective housing, and the _______.
anode
cathode
glass envelope
focusing cup
As an x-ray tube ages, the inside can become coated with tungsten, which can cause ______ in the tube.
convection
anode pitting
off-focus radiation
arcing
When electrons bombard the target, ___% of their kinetic energy is converted to heat.
10
25
50
99
Because of the line focus principal, the effective focal spot size decreases with
decreasing ___________.
target angle
rotor speed
window thickness
space charge
The x-ray intensity is lower on the anode side of the tube because of the ________ .
line focus principle
heel effect
focusing cup
filament length
The heat units formula for a 3 Φ 6p x-ray machine is:
kVp x mA x s
1.35 x kVp x mA x s
1.41 x kVp x mA x s
1.66 x kVp x mA x s
A projectile electron interacts with the nuclear field of a target atom causing the projectile electron to 'brake' and lose kinetic energy. This kinetic energy loss is re-emitted as an x-ray photon. This describes the production of:
characteristic radiation
bremsstrahlung radiation
compton radiation
photoelectric radiation
At 55 kVp, ______of the x-rays produced are
bremsstrahlung.
15%
80%
100%
None of the above
