equipment Flashcards
(199 cards)
1
Q
- The _______ is the source of radiation in the x-ray tube.
a. filament
b. focal spot
c. focusing cup
d. stator
A
b. focal spot
2
Q
Because of the line focus principle, the effective focal spot size decreases with decreasing
a. target angle.
b. rotor speed.
c. window thickness.
d. space charge.
A
a. target angle.
3
Q
High capacity tube rotors revolve at _________.
a. 2000 rpm
b. 3600 rpm
c. 6000 rpm
d. 10,000 rpm
A
d. 10,000 rpm
4
Q
The x-ray intensity is lower on the anode side of the tube because of the
a. line focus principle.
b. heel effect.
c. focusing cup.
d. filament length.
A
b. heel effect.
5
Q
The cathode side of the tube should be towards the ________ part of the patient.
a. upper
b. lower
c. thicker
d. thinner
A
c. thicker
6
Q
What is the formula for heat units for a three-phase, six-pulse x-ray machine?
a. kVp × mA × seconds
b. 1.35 × kVp × mA × seconds
c. 1.41 × kVp × mA × seconds
d. 1.66 × kVp × mA × seconds
A
b. 1.35 × kVp × mA × seconds
7
Q
Tube failure can occur from
a. extrafocal radiation.
b. short exposure times.
c. high kVp techniques.
d. long exposure times.
A
d. long exposure times.
8
Q
The filament in an x-ray tube is about ______ in length.
a. 1–2 cm
b. 3–4 cm
c. 8–10
d. 10–20 cm
A
a. 1–2 cm
9
Q
A dual focus tube has two
a. anodes.
b. filaments.
c. rotors.
d. stators.
A
b. filaments.
10
Q
Each tube has its own tube rating chart to show
a. housing cooling times.
b. anode cooling times.
c. maximum exposure times.
d. maximum patient doses.
A
c. maximum exposure times.
11
Q
The _________ is/are outside the glass envelope.
a. stators
b. rotor
c. focal spot
d. filaments
A
a. stators
12
Q
Extrafocal or off-focus radiation is produced from
a. overheated anodes.
b. scattered x-rays.
c. rebounding electrons.
d. dual focus cathodes.
A
c. rebounding electrons.
13
Q
The heel effect is caused by the
a. stator windings.
b. anode angle.
c. exposure times.
d. induction motor.
A
b. anode angle.
14
Q
The effective focal spot size is __________ the actual focal spot size.
a. equal to
b. larger than
c. equal to or larger than
d. smaller than
A
d. smaller than
15
Q
Localized pitting or cracking on the anode can occur from
a. filament vaporization.
b. a single excessive exposure.
c. long exposure times.
d. high kVp and low mA.
A
b. a single excessive exposure.
16
Q
Projectile electrons travel from
a. anode to cathode.
b. cathode to anode.
c. target to patient.
d. inner shell to outer shell.
A
b. cathode to anode.
17
Q
During an exposure most of the _________ energy of the projectile electrons is converted to __________.
a. kinetic, x-rays
b. x-ray, kinetic
c. kinetic, heat
d. heat, kinetic
A
c. kinetic, heat
18
Q
At the target, the projectile electrons interact with
a. outer shell electrons.
b. inner shell electrons.
c. atomic nuclei.
d. Both a and b.
A
d. Both a and b.
19
Q
The efficiency of x-ray production is ____________ the tube current.
a. indirectly proportional to
b. directly proportional to
c. not affected by
d. strongly affected by
A
D
20
Q
Most of the heat generated at the target is due to
a. inner-shell ionization.
b. outer-shell excitation.
c. nucleus bombardment.
d. K x-rays.
A
b. outer-shell excitation.
21
Q
The efficiency of x-ray production increases as ___ increases.
a. mA
b. kVp
c. time
d. Both a and b.
A
D. Both a and b
22
Q
Approximately ____ of the kinetic energy of the projectile electrons is converted to x- target.
a. 1%
b. 10%
c. 50%
d. 99%
A
a. 1%
23
Q
Electron interactions at the inner shell of the target atoms produce __________ radiation.
a. gamma
b. bremsstrahlung
c. characteristic
d. All of the above.
A
c. characteristic
24
Q
The useful characteristic x-rays from tungsten targets are ______ x-rays.
a. K-shell
b. L-shell
c. M-shell
d. N-shell
A
a. K-shell
25
Characteristic K-shell x-rays have an effective energy of ______ keV.
a. 0.6
b. 3
c. 12
d. 69
d. 69
26
Most of the x-rays produced at the target are __________.
a. bremsstrahlung
b. characteristic
c. gamma
d. Beta
a. bremsstrahlung
27
At 55 kVp _____ of the x-rays produced are bremsstrahlung.
a. 15%
b. 80%
c. 100%
d. none
c. 100%
28
Bremsstrahlung x-rays are produced by ________ at the target.
a. outer shell excitation.
b. slowing electrons.
c. K-shell interactions.
d. L-shell interactions.
b. slowing electrons.
29
Characteristic x-rays are produced by
a. braking electrons.
b. excitation of outer shell electrons.
c. nuclear fragmentation.
d. released binding energy.
D. Released binding energy
30
The quantity of bremsstrahlung radiation increases proportionately with increased ______.
a. kVp
b. mAs
c. filtration
d. rotor speed
b. mAs
31
An exposure taken at 100 kVp would have a continuous emission spectrum with a maximum energy of ______ keV.
a. 30
b. 69
c. 100
d. 140
C. 100
32
The _____ of an x-ray beam is higher when the peak of the emission spectrum is further to the _____.
a. quality, right
b. quantity, right
c. quality, left
d. quantity, left
a. quality, right
33
An increase in mAs would _________ the ________ of the emission spectrum.
a. increase, position only
b. increase, amplitude only
c. increase, amplitude and position
d. not affect, amplitude and position
b. increase, amplitude only
34
An increase in kVp would ________ the ________ of the emission spectrum.
a. increase, position only
b. increase, amplitude only
c. increase, amplitude and position
d. not affect, amplitude and position
c. increase, amplitude and position
35
Changes in _______ result in directly proportional changes in the amplitude of the emission spectrum.
a. mA
b. time
c. kVp
d. Both a and b.
d. Both a and b.
36
The discrete portion of the x-ray emission spectrum would change position with a change in _________.
a. kVp
b. target material
c. voltage ripple
d. Both a and b.
b. target material
37
The amplitude of the emission spectrum is ________ with a _______ generator than/as with a three-phase generator.
a. lower, single-phase
b. lower, high frequency
c. higher, single-phase
d. the same, single-phase
a. lower, single-phase
38
A 15% increase in kVp is equivalent to
a. increasing the mAs 15%.
b. doubling the mAs.
c. Increasing the mAs 1½ times.
d. tripling the mAs.
b. doubling the mAs.
39
How does added filtration affect the emission spectrum?
a. increased amplitude and a shift to the right
b. increased amplitude and a shift to the right
c. reduced amplitude and a shift to the right
d. reduced amplitude and a shift to the left
c. reduced amplitude and a shift to the right
40
Roentgens (or grays) is the measurement for x-ray ________.
a. quantity
b. exposure
c. intensity
d. All of the above.
d. All of the above.
41
The number of useful x-rays in the beam defines x-ray
a. kVp.
b. quality.
c. quantity.
d. mAs.
c. quantity.
42
Standard x-ray machines produce about ____ mR/mAs at 70 kVp measured at 100 cm SID.
a. 2
b. 5
c. 10
d. 20
b. 5
43
X-ray quantity increases in direct proportion to increases in ______.
a. mAs
b. kVp
c. distance
d. filtration
a. mAs
44
If the distance from the source to the image (SID) is reduced by half, how is the x-ray intensity at the image affected?
a. It is increased 4 times.
b. It is doubled.
c. It is reduced by ½.
d. It is reduced by ¼.
a. It is increased 4 times.
45
If filter thickness is _______, then x-ray intensity is _______.
a. reduced, reduced
b. increased, reduced
c. reduced, increased
d. Both b and c.
d. Both b and c.
46
A 10% increase in kVp has ______ effect on x-ray intensity than/as a 10% increase in mAs.
a. the same
b. much greater
c. less
d. much less
b. much greater
47
If x-ray quantity is doubled, the optical density on the finished radiograph will be
a. reduced by half.
b. just slightly increased.
c. increased by a factor of two.
d. increased by a factor of four.
c. increased by a factor of two.
48
If a technologist changes the technique from 70 kVp @ 200 mAs to 70 kVp @ 400 mAs, then the x-ray intensity will ______ and optical density will __________.
a. double, double.
b. double, remain the same.
c. remain the same, will remain the same.
d. will remain the same, double.
a. double, double.
49
The inverse square law has the same effect on optical density and x-ray _______.
a. intensity
b. exposure
c. quantity
d. All of the above.
d. All of the above.
50
21. The production of heat at the anode is directly proportional to
a. rotor speed.
b. filament current.
c. kVp.
d. tube current.
B. Filament current
51
An increase of 15% in kVp is equivalent to increasing mAs _____.
a. 15%.
b. 30%.
c. 50%
d. 100%.
d. 100%.
52
If the intensity of a 70 kVp exposure at 20 mAs is 100 mR, what would it be at 5 mAs?
a. 25 mR
b. 50 mR
c. 200 mR
d. 400 mR
a. 25 mR
53
If an exposure is 50 mR at an SID of 40 inches, what would the exposure be at an SID of 60 inches?
a. 22.2 mR
b. 33.3 mR
c. 75 mR
d. 112.5 mR
a. 22.2 mR
54
X-ray intensity is proportional to ______.
a. distance
b. kVp
c. kVp2
d. filtration
c. kVp2
55
The penetrability of an x-ray beam is called x-ray _______.
a. quantity
b. quality
c. intensity
d. All of the above.
b. quality
56
An x-ray beam that could pass through dense tissue would have high _______.
a. penetrability
b. quality
c. quantity
d. Both a and b.
d. Both a and b.
57
A low quality beam would also have low
a. penetrability.
b. quantity.
c. mAs.
d. intensity.
a. penetrability.
58
Beam quality is affected by
a. mAs and distance.
b. kVp and mAs.
c. kVp and filtration.
d. filtration and mAs.
c. kVp and filtration.
59
The half value layer (HVL) of an x-ray beam is a measurement of beam ______.
a. intensity
b. quality
c. quantity
d. All of the above.
b. quality
60
Image contrast is affected by ________.
a. beam quality
b. kVp
c. mAs
d. Both a and b.
d. Both a and b.
61
The HVL is lowered by a decrease in _____.
a. kVp
b. mAs
c. distance
d. Both a and c.
A
62
X-ray beam quality is improved by
a. lowering kVp.
b. decreasing filtration.
c. increasing filtration.
d. increasing distance.
c. increasing filtration.
63
The main purpose of added filtration is to reduce
a. the HVL.
b. patient dose.
c. beam quality.
d. beam penetrability.
b. patient dose.
64
Added filtration will ________ beam quality and _______ beam quantity.
a. decrease, increase
b. decrease, decrease
c. increase, decrease
d. increase, increase
c. increase, decrease
65
A compensating filter is used to create _________ optical density with a body part of ___ thickness.
a. uniform, non-uniform
b. non-uniform, non-uniform
c. non-uniform, uniform
d. uniform, uniform
a. uniform, non-uniform
66
The two primary forms of x-ray interaction in the diagnostic range are
a. Compton scattering and photoelectric absorption.
b. Compton scattering and pair production.
c. photoelectric absorption and coherent scattering.
d. coherent scattering and Thompson scattering.
a. Compton scattering and photoelectric absorption.
67
An incident x-ray interacts with an atom without ionization during _____________.
a. photoelectric absorption
b. Compton scattering
c. coherent scattering
d. pair production
c. coherent scattering
68
An outer-shell electron is ejected and the atom is ionized with
a. photoelectric interactions.
b. Compton interactions.
c. coherent scattering.
d. pair production.
b. Compton interactions.
| U
69
Which x-ray interaction involves the ejection of the K-shell electron?
a. coherent scattering
b. Compton interaction
c. pair production
d. photoelectric absorption
d. photoelectric absorption
70
The scattered x-ray from a Compton interaction usually retains ________ of the energy of the incident photon.
a. none
b. little
c. most
d. all
c. most
71
Compton scatter is directed at (a) _______ angle from the incident beam.
a. 180º
b. 90º
c. 0º
d. any
D. Any
72
As kVp _________, the probability of photoelectric absorption __________.
a. increases, remains the same
b. increases, decreases
c. decreases, decreases
d. decreases, remains the same
b. increases, decreases
73
There is complete absorption of the incident x-ray photon with
a. photoelectric effect.
b. Compton interaction.
c. pair production.
d. coherent scatter.
a. photoelectric effect.
74
_________ occurs only at the very high energies used in radiation therapy and in nuclear medicine PET imaging.
a. Coherent scatter
b. Compton scatter
c. Photoelectric absorption
d. Pair production
d. Pair production
75
Only at energies above 10 MeV can ___________ take place.
a. photodisintegration
b. pair production
c. Compton scatter
d. photoelectric absorption
a. photodisintegration
76
When the mass density of the absorber is __________, it results in __________ Compton scatter.
a. decreased, increased
b. increased, increased
c. increased, decreased
d. decreased, decreased
b. increased, increased
77
K-shell binding energy increases with increasing ________.
a. mass density
b. kVp
c. atomic number
d. mAs
c. atomic number
78
Which has the greatest mass density?
a. fat
b. soft tissue
c. bone
d. air
c. bone
79
Image fog in diagnostic imaging is caused by
a. photoelectric absorption.
b. Compton scatter.
c. pair production.
d. All of the above.
b. Compton scatter.
80
Because of differential absorption, about ___ of the incident beam from the x-ray tube contributes to the finished image.
a. 0.5%
b. 10%
c. 50%
d. 95%
a. 0.5%
81
Differential absorption is dependent on the
a. kVp of the exposure.
b. atomic number of the absorber.
c. mass density of the absorber.
d. All of the above.
d. All of the above.
82
Attenuation is caused by __________.
a. absorption
b. scattering
c. transmission
d. Both a and b.
d. Both a and b.
83
Barium is a good contrast agent because of its
a. low atomic number.
b. high atomic number.
c. light color.
d. low density.
b. high atomic number.
84
The use of contrast agents increases the amount of
a. differential absorption.
b. Compton scatter.
c. photoelectric absorption.
d. All of the above.
d. All of the above.
85
A negative contrast agent is _____.
a. air
b. iodine
c. barium
d. water
A. AIR
86
X-rays transmitted without interaction contribute to
a. photoelectric absorption.
b. the radiographic image.
c. the image fog.
d. beam attenuation.
B. The radiographic image
87
Compton interactions, photoelectric absorption, and transmitted x-rays all contribute to ___________.
a. image fog
b. differential absorption
c. patient dose
d. attenuation
b. differential absorption
88
High kVp techniques reduce
a. patient dose.
b. differential absorption.
c. image fog.
d. All of the above.
a. patient dose.
89
At energies below 40 keV, the predominant x-ray interaction in soft tissue and bone is ________.
a. coherent scatter
b. Compton scatter
c. photoelectric absorption
d. photodisintegration
C. Photoelectric absorption
90
If 5% of an incident beam is transmitted through a body part, then 95% of that beam was
a. scattered.
b. attenuated.
c. absorbed.
d. back-scattered.
b. attenuated.
91
The smallest quantity of any type of electromagnetic radiation is a ________.
a. photon
b. electron
c. neutrino
d. quark
A. Photon
92
What is the velocity of all electromagnetic radiation?
a. 8 × 103 m/s
b. 2 × 108 m/s
c. 3 × 108 m/s
d. 4 × 103 m/s
c. 3 × 10^8 m/s
93
The rate of rise and fall of a sine wave is called its _______.
a. amplitude
b. frequency
c. wavelength
d. velocity
b. frequency
94
A hertz (Hz) is equal to
a. 10^3 cycles per second.
b. 10^2 cycles per second.
c. 10 cycles per second.
d. 1 cycle per second.
d. 1 cycle per second.
95
What is the electromagnetic wave equation?
a. c = fë
b. c = f/ë
c. c = fv
d. c = f–ë
c. c = fv
96
The _________ of electromagnetic radiation is constant.
a. amplitude
b. velocity
c. frequency
d. Wavelength
b. velocity
97
If the wavelength of a beam of electromagnetic radiation increases by a factor of 2, then its frequency must
a. double.
b. increase four times.
c. decrease by half.
d. remain constant.
c. decrease by half.
98
The intensity of radiation _____________ in ___________ proportion to the square of the distance of the object from the source.
a. increases, direct
b. decreases, direct
c. increases, inverse
d. decreases, inverse
d. decreases, inverse
99
The reduction of radiation intensity due to scattering and absorption is called __________.
a. reflection
b. refraction
c. attenuation
d. dispersion
c. attenuation
100
The velocity of light is written as
a. c = 8 × 108 m/s.
b. c = 108 m/s.
c. c = 3 × 108 m/s.
d. c = 3 × 10 m/s.
c. c = 3 × 108 m/s.
101
The maximum number of electrons that can exist in an electron shell is calculated with the formula _____.
a. 2n
b. 2n2
c. 2/n
d. 2/n2
b. 2n^2
102
The shell number of an atom is called the
a. alpha particle.
b. chemical element.
c. principal quantum number.
d. half-life number.
c. principal quantum number.
103
The unit of measure of radiation in air is the ________.
a. rem
b. Roentgen
c. seivert
d. rad
b. Roentgen
104
The ________ is the unit used to describe the dose of ionizing radiation received by a patient.
a. rem
b. seivert
c. rad
d. Roentgen
c. rad
105
What unit is used to measure occupational dose?
a. rem
b. rad
c. Roentgen
d. Curie
a. rem
106
The gray is equivalent to _____.
a. .001 rems
b. .01 rems
c. .001 rads
d. .01 rads
d. .01 rads
107
A measure of 10-3 rads is a
a. megarad.
b. millirad.
c. microrad.
d. centirad.
b. millirad.
108
Radioactive material is measured in _______.
a. rads
b. rems
c. seiverts
d. curies
d. curies
109
A seivert is equal to a rem multiplied by _____.
a. 0.0001
b. 0.001
c. 0.01
d. 0.1
c. 0.01
110
The intensity of radiation on an object is reduced with distance because the radiation
a. reduces its velocity.
b. increases in wavelength.
c. loses its energy.
d. is spread out over a greater area.
d. is spread out over a greater area.
111
112. If the intensity of light from a flashlight is 4 millilumens (mlm) at a distance of 3 feet, what will the intensity be at 6 feet?
a. 0.4 millilumens
b. 1 millilumen
c. 2 millilumens
d. 16 millilumens
b. 1 millilumen
112
113. The diagnostic range of x-ray energy is
a. 30 to 150 kVp.
b. 200 to 300 kVp.
c. 300 to 1000 kVp.
d. over 1 MV.
a. 30 to 150 kVp.
113
114. The energy of a photon is directly proportional to its
a. amplitude.
b. frequency.
c. velocity.
d. wavelength.
b. frequency.
114
115. The mass equivalent of a 100 KeV photon of radiation can be calculated using the
a. inverse square formula.
b. equivalent Planck equation.
c. relativity formula.
d. Planck quantum equation.
C
115
```
******
X-rays are usually identified by their ________.
a. energy
b. velocity
c. wavelength
d. hertz
```
A
116
117. The lowest energy range of the electromagnetic spectrum is
a. sound waves.
b. radio waves.
c. gamma rays.
d. microwaves.
b. radio waves.
117
118. Gamma rays are produced in the _________ of the atom.
a. outer electron shell
b. inner electron shell
c. nucleus
d. K-shell
c. nucleus
118
119. Photons tend to interact with matter _________ its wavelength.
a. equal in size to
b. larger in size than
c. smaller in size than
d. unequal in size to
a. equal in size to
119
120. Photons with the highest frequencies have the
a. highest velocity.
b. lowest energy.
c. longest wavelengths.
d. shortest wavelengths.
d. shortest wavelengths.
120
121. The smallest unit of electrical charge is the
a. electron.
b. proton.
c. neutron.
d. neutrino.
a. electron.
121
122. Electrification occurs through the movement of
a. only protons.
b. protons and electrons.
c. only electrons.
d. electrons and neutrons.
c. only electrons.
122
123. Like charges __________ and unlike charges _________.
a. repel, repel
b. attract, attract
c. attract, repel
d. repel, attract
d. repel, attract
123
124. Electrostatic force is __________ proportional to the distance between charges and __________ proportional to the product of the charges.
a. directly, inversely
b. inversely, directly
c. inversely, inversely
d. directly, directly
B
124
The charges on an electrified object are distributed
a. in the center of the object.
b. on the side nearest the charge.
c. on the top side of the object.
d. evenly throughout the object.
d. evenly throughout the object.
125
126. On the surface of an electrified object the charges concentrate
a. on the top side.
b. on the underside.
c. on the sharpest curvatures.
d. on the smoothest curvatures.
c. on the sharpest curvatures.
126
* **
127. A _______ is a source of direct current.
a. wall socket
b. battery
c. generator
d. spark
b. battery
127
128. What is the unit of electric potential?
a. watt
b. amp
c. volt
d. Ohm
c. volt
128
129. An electric potential applied to a conductor produces a(n)
a. electric current.
b. magnetic field.
c. electric insulator.
d. Both a and b.
d. Both a and b.
129
130. An alternating (AC) current is represented by a ______ line.
a. sinusoidal
b. horizontal
c. vertical
d. descending
a. sinusoidal
130
131. A _______ uses direct current.
a. hair dryer
b. toaster
c. microwave
d. flashlight
d. flashlight
131
Alternating current is produced by a ______.
a. battery
b. generator
c. capacitor
d. semiconductor
b. generator
132
133. What is Ohm’s Law?
a. I = V/R
b. V = I/R
c. R = VI
d. I = VR
A
133
134. A charged particle in motion creates a(n)
a. negative charge.
b. positive charge.
c. magnetic field.
d. electrostatic charge.
c. magnetic field.
134
135. Electrical power is measured in _____.
a. coulombs
b. amperes
c. volts
d. Watts
d. Watts
135
136. Rubber and glass are ________.
a. semiconductors
b. conductors
c. insulators
d. superconductors
c. insulators
136
137. The rotation of electrons on their axis is the property called
a. magnetic force.
b. electron spin.
c. unified field theory.
d. magnetic induction.
b. electron spin.
137
138. When a group of dipoles are aligned they create a
a. magnetic domain.
b. paramagnetic material.
c. magnetic resonance.
d. a north pole.
a. magnetic domain.
138
139. In the United States alternating current goes through a complete cycle every _____ second.
a. 1/120
b. 1/100
c. 1/60
d. 1/30
c. 1/60
139
140. What is the SI unit of magnetic field strength?
a. ampere
b. tesla
c. dipole
d. ohm
b. tesla
140
141. The force between magnetic poles is proportional to the ________ of the magnetic pole strengths divided by the ________ of the distance between them.
a. square, sum
b. sum, square
c. square, product
d. product, square
d. product, square
141
142. What type of material can be made magnetic when placed in an external magnetic field?
a. diamagnetic
b. ferromagnetic
c. paramagnetic
d. nonmagnetic
B
142
143. Like magnetic poles ______ and unlike magnetic poles _______.
a. attract, attract
b. repel, repel
c. repel, attract
d. attract, repel
c. repel, attract
143
144. Wood, glass, and plastic are ________ materials.
a. paramagnetic
b. magnetic
c. diamagnetic
d. ferromagnetic
c. diamagnetic
144
145. The magnetic intensity of an electromagnet is greatly increased by the addition of a(n) ________ core.
a. wood
b. iron
c. aluminum
d. copper
b. iron
145
146. The first batteries were made of stacks of _______ and ______ plates sandwiched together.
a. zinc, glass
b. iron, zinc
c. zinc, copper
d. aluminum, copper
c. zinc, copper
146
147. Oersted discovered that an electric current flowing through a wire would affect a _______ nearby.
a. battery
b. light bulb
c. wire
d. compass
d. compass
147
148. Faraday’s experiments proved that a current could be induced by a magnetic field only if the field is
a. stationary.
b. changing.
c. motionless.
d. vibrating.
b. changing.
148
149. A magnet created by a coil of wire is called a ________.
a. solenoid
b. battery
c. ferromagnet
d. electromagnet
a. solenoid
149
150. The magnitude of an induced current depends on the
a. angle of the conductor to the magnetic field.
b. number of turns in the conductor.
c. velocity of the magnetic field as it moves past the conductor.
d. All of the above.
d. All of the above.
150
151. Lenz’s law states that an induced current flows in a direction that _________ the action that produces it.
a. opposes
b. doubles
c. amplifies
d. reverses
a. opposes
151
An electrical component that works through self-induction is the ________.
a. rectifier
b. battery
c. generator
d. transformer
d. transformer
152
153. An electric current can be induced in a coil of wire if it is placed near a(n)
a. electric generator.
b. electromagnet.
c. direct current.
d. commutator ring.
b. electromagnet.
153
154. A coil of wire placed between two poles of a magnet with a strong magnetic field would be an ___________.
a. autotransformer
b. induction motor
c. electric motor
d. electric generator
D
154
155. A cummutator ring is used to change ________ current to _______ current in an electric generator.
a. alternating, amplified
b. direct, amplified
c. alternating, direct
d. direct, alternating
c. alternating, direct
155
156. The most efficient type of transformer is the
a. shell-type transformer.
b. autotransformer.
c. closed-core transformer.
d. single-winding transformer.
a. shell-type transformer.
156
157. A device that converts any form of energy into electrical energy is a source of
a. thermionic emission.
b. electromotive force.
c. magnetic strength.
d. gravitational force.
b. electromotive force.
157
158. The number of windings on the primary side of a step-up transformer are always ____ the number of windings on the secondary side.
a. less than
b. greater than
c. the same as
d. half of
a. less than
158
159. Mechanical motion produces electric current in the ________.
a. electromagnet
b. electric motor
c. electric transformer
d. electric generator
D
159
160. The two basic types of induction are _________ induction and _________ induction.
a. electronic, mechanical
b. double, single
c. self, mutual
d. AC, DC
c. self, mutual
160
161. A transformer converts
a. mechanical energy to electrical energy.
b. electrical potential to higher or lower intensity.
c. electrical energy to mechanical energy.
d. mechanical energy to magnetic fields.
b. electrical potential to higher or lower intensity.
161
A transformer has 100 coils on the primary side and 300 coils on the secondary side. What will the voltage be on the secondary side if the primary side is supplied with 120 volts?
a. 100 V
b. 300 V
c. 360 V
d. 3600 V
c. 360 V
162
163. A transformer has 600 coils on its primary side and 30 coils on its secondary side. What is the voltage on the secondary side when the primary side is 220 V?
a. 4400 V
b. 660 V
c. 22 V
d. 11 V
d. 11 V
163
164. The current to a transformer must be supplied by a(n)
a. AC source.
b. DC source.
c. battery.
d. Any of the above.
a. AC source.
164
165. What is the mechanical source of energy for electrical generators that supply electricity to our cities?
a. waterfalls
b. steam from atomic power
c. windmills
d. Any of the above.
d. Any of the above.
165
166. The three main parts of the x-ray imaging system are the x-ray tube, _____, and ______.
a. protective barrier, tabletop
b. operating console, high voltage generator
c. rectification circuit, operating console
d. crane assembly, tabletop
B
166
167. The operating console contains circuits that are
a. both high voltage and low voltage.
b. high voltage only.
c. low voltage only.
d. non-voltage.
C
167
168. Variations in power distribution to the x-ray machine are corrected by the
a. line voltage compensator.
b. high voltage autotransformer.
c. full-wave rectifier.
d. automatic exposure control.
a. line voltage compensator.
168
169. The first component to receive power in the x-ray circuit is the _________.
a. mA meter
b. high voltage transformer
c. rectifier
d. Autotransformer
d. Autotransformer
169
170. The autotransformer has ______ winding(s).
a. one
b. two
c. three
d. four
a. one
170
171. The _________ circuit provides electrons for the x-ray tube current.
a. rectifier
b. autotransformer
c. high voltage
d. filament
d. filament
171
172. Thermionic emission at the filament determines the _______ across the x-ray tube during an exposure.
a. kilovoltage
b. milliamperage
c. resistance
d. magnetism
b. milliamperage
172
173. A step-down transformer is located in the _________ circuit.
a. tube
b. timing
c. filament
d. rectifier
c. filament
173
174. The most accurate type of timer is the ___________ timer.
a. mechanical
b. electronic
c. synchronous
d. mAs
b. electronic
174
175. The automatic exposure control (AEC) terminates the exposure when
a. the set time is reached.
b. set radiation leaves the x-ray tube.
c. sufficient radiation reaches the image receptor.
d. the correct mAs is reached.
c. sufficient radiation reaches the image receptor.
175
176. The mAs timer is usually set to give the ________ mA at the _______ time.
a. highest, highest
b. highest, shortest
c. lowest, shortest
d. lowest, highest
b. highest, shortest
176
177. The step-up transformer increases voltage ____________ times.
a. 500–1000
b. 200–300
c. 60–120
d. 20–50
A
177
178. A diode allows electrons to flow
a. from anode to cathode.
b. from cathode to anode.
c. from cathode to cathode.
d. from anode to anode.
b. from cathode to anode.
178
179. The high voltage generator contains the high voltage transformer, the ______ and the _________.
a. autotransformer, timer
b. timer, rectifiers
c. kVp meter, filament transformer
d. filament transformer, rectifiers
D
179
180. The difference in the waveform between the primary and secondary sides of the high voltage transformer is the ________.
a. frequency
b. velocity
c. amplitude
d. All of the above.
c. amplitude
180
181. In modern imaging systems, the components for rectification are
a. capacitor discharge generators.
b. high frequency transformers.
c. vacuum tubes.
d. solid state semiconductors.
d. solid state semiconductors.
181
182. With half-wave rectification the current flows through the x-ray tube during the ____ part of the cycle.
a. zero
b. positive or negative
c. positive
d. negative
c. positive
182
183. Full-wave rectified, three-phase units provide an x-ray beam at _______ per second.
a. 1 pulse
b. 60 pulses
c. 120 pulses
d. 360 pulses
D. 360 pulses
183
184. Voltage across the x-ray tube is most constant with
a. high frequency generators.
b. single-phase, half-wave rectification.
c. single-phase, full-wave rectification.
d. three-phase, full-wave rectification.
a. high frequency generators.
184
185. Most mammography units operate with _______________ generators.
a. capacitor discharge
b. high frequency
c. single-phase
d. three-phase
b. high frequency
185
186. A single-phase waveform has ______ ripple.
a. 1%
b. 4%
c. 14%
d. 100%
d. 100%
186
187. The x-ray beam generated by the circuit with the ________ voltage ripple has the ____quantity and quality.
a. highest, lowest
b. highest, highest
c. lowest, highest
d. lowest, lowest
c. lowest, highest
187
188. The principal disadvantage of three-phase equipment is ________.
a. efficiency
b. cost
c. operation
d. beam quality
B. Cost
| C**********
188
189. What is the industry standard formula for calculating high voltage generator power?
a. Power = min mA (@100 kVp and 100 ms) × 100 kVp
b. Power = min mA (@100 kVp and 100 ms) ÷ 100 kVp
c. Power = max mA (@100 kVp and 100 ms) × 100 kVp
d. Power = max mA (@100 kVp and 100 ms) ÷ 100 kVp
C
189
190. The x-ray generator with the lowest power rating is the _________ imaging system.
a. high frequency
b. three-phase, 12-pulse
c. three-phase, 6-pulse
d. single-phase
d. single-phase
190
191. The most widely used support structure for the x-ray tube is the
a. C-arm.
b. floor-to-ceiling mount.
c. ceiling support system.
d. floor support system.
c. ceiling support system.
191
192. The external structure of the x-ray tube includes the support structure, the protective housing, and the _________.
a. anode
b. cathode
c. glass envelope
d. focusing cup
c. glass envelope
192
193. As an x-ray tube ages, the inside can become coated with tungsten, which can cause ________ in the tube.
a. convection
b. anode pitting
c. off-focus radiation
d. arcing
d.arcing
193
194. The negative side of the x-ray tube holds the
a. filament.
b. anode.
c. target.
d. rotor.
a. filament.
194
195. What is the most common cause of tube failure?
a. cracked anode
b. loose bearings
c. pitted anode
d. tungsten vaporization
d. tungsten vaporization
195
196. The filament is made of __________.
a. graphite
b. tungsten
c. copper
d. molybdenum
B. tungsten
196
197. Thermionic emission at the filament creates a __________.
a. space charge
b. grid control
c. line focus
d. heel effect
a. space charge
197
198. When electrons bombard the target, ___ of their kinetic energy is converted to heat.
a. 10%
b. 25%
c. 50%
d. 99%
d. 99%
198
199. The target of the rotating anode is usually coated with a _______ alloy.
a. molybdenum
b. graphite
c. Tungsten
c. Tungsten
199
200. The rotating anode is turned by a
a. thermal cushion.
b. rotating belt.
c. magnetic field.
d. mechanical pulley.
c. magnetic field.
