ARRT PRACTICE QUESTIONS & 100% CORRECT ANSWERS
A CCD may be used in the television system instead of what device(s)? - ANSWER-A
charge-coupled device (CCD) is a solid-state imager that may be used instead of
vidicon and Plumbicon tubes to send the signal to a television monitor. The c-arm is a
structural device that keeps the x-ray tube and image receptor an appropriate
distance apart. Automatic brightness control does not involve such a device. Output
phosphor is a part of the image-intensifier tube.
.A change in wavelength will always correspond to a change in? - ANSWER-
Wavelength and frequency are, by their nature, tied to one another.
.A compound's smallest component is the: - ANSWER-The smallest component of a
compound is the molecule, which still has the characteristics of the compound. An
electron is an elementary particle with one negative charge. An atom is the smallest
particle of an element capable of entering into a reaction. An element is a substance
made up of atoms with the same atomic number and the same chemical properties;
it cannot be broken down further without changing its chemical properties.
.A device used for most quality control testing is the: - ANSWER-The digital dosimeter
allows for several quality control tests to be done with one device. A sensitometer is
an optical step wedge that is used to produce a characteristic curve. A densitometer
measures optical density of exposed film. The ionization chamber detects and
measures radiation intensity in areas outside of protective barriers.
.A material that may act as an insulator or conductor under different conditions is
called a: - ANSWER-This describes semiconductors, which are used extensively
,throughout the x-ray machine. A rectifier is the part of an x-ray machine that changes
alternating current to direct current. A solenoid is a coil of wire that creates
overlapping force field lines. A sine wave is a wave of electromagnetic radiation.
.A step-down transformer is used in the x-ray circuit to? - ANSWER-A step-down
transformer is used in the x-ray circuit to decrease voltage and increase current flow
to the cathode. This provides the electrons needed for thermionic emission. A
rectifier changes AC to DC.
.An interaction that produces x-rays at the anode as a result of outer shell electrons
filling holes in the K shell is called? - ANSWER-This is a description of characteristic
radiation. Although both characteristic and Brems radiation produce x-rays at the
anode, Brems radiation occurs when a projectile electron misses the outer shell
target electrons and moves close to the nucleus. Photoelectric interaction does
involve outer shell electrons filling holes in the K shell, but it does not produce x-rays
at the anode. Compton interaction produces scatter radiation. ,
.An x-ray machine that makes maximum use of heat loading potential uses a(n): -
ANSWER-A falling load generator allows for very short exposure times by taking
advantage of tube heat-loading potential. When the maximum heat load of the tube
has been reached for a set mA, the generator drops the mA to the next lower level
that the tube can handle (falling heat load). ,
.Atomic mass is represented by the letter? - ANSWER-The letter A is used to
represent atomic mass &which is the number of protons and neutrons. The letter Z
represents atomic number; M and Q are names of an atom's electron shells.
.Atomic number is represented by the letter? - ANSWER-The letter Z represents
atomic number, which is equal to the number of protons. The letter A is used to
, represent atomic mass; M and Q are names of electron shells of an atom.
.Atoms with the same number of protons but with a different number of neutrons
are called? - ANSWER-Isotopes are atoms with the same number of protons but with
a different number of neutrons. Radioactive isotopes are used in nuclear medicine
imaging because they emit gamma rays. In a stable atom the number of protons,
electrons, and neutrons are equal. Ions have too many or too few electrons, not
neutrons.
.Auto-transformers operate on the principle of? - ANSWER-Auto-transformers
operate on the principle of self-induction. These devices need alternating current to
operate. Mutual induction is key to the operation of step-up and step-down
transformers. Current conversion is performed by a rectifier.
.Beam quality is expressed using what unit of measurement? - ANSWER-X-ray beam
quality is expressed numerically by half-value layer, the amount of filtration needed
to reduce the intensity of the beam by half. Gray and mAs are related to x-ray
quantity, not quality.
.Current that flows back and forth is called? - ANSWER-Alternating current (AC) flows
back and forth, whereas direct current (DC) flows in one direction only. A rectified
current would be one that has undergone a change from AC to DC.
.Electron energy is converted to light in what part of the image-intensifier tube? -
ANSWER-Electron energy is converted to light by the output phosphor in amounts 50
to 75 times greater than at the photocathode. At this point, the image is brighter and
smaller. The input phosphor receives exit x-rays from the patient and converts them
into visible light.
A CCD may be used in the television system instead of what device(s)? - ANSWER-A
charge-coupled device (CCD) is a solid-state imager that may be used instead of
vidicon and Plumbicon tubes to send the signal to a television monitor. The c-arm is a
structural device that keeps the x-ray tube and image receptor an appropriate
distance apart. Automatic brightness control does not involve such a device. Output
phosphor is a part of the image-intensifier tube.
.A change in wavelength will always correspond to a change in? - ANSWER-
Wavelength and frequency are, by their nature, tied to one another.
.A compound's smallest component is the: - ANSWER-The smallest component of a
compound is the molecule, which still has the characteristics of the compound. An
electron is an elementary particle with one negative charge. An atom is the smallest
particle of an element capable of entering into a reaction. An element is a substance
made up of atoms with the same atomic number and the same chemical properties;
it cannot be broken down further without changing its chemical properties.
.A device used for most quality control testing is the: - ANSWER-The digital dosimeter
allows for several quality control tests to be done with one device. A sensitometer is
an optical step wedge that is used to produce a characteristic curve. A densitometer
measures optical density of exposed film. The ionization chamber detects and
measures radiation intensity in areas outside of protective barriers.
.A material that may act as an insulator or conductor under different conditions is
called a: - ANSWER-This describes semiconductors, which are used extensively
,throughout the x-ray machine. A rectifier is the part of an x-ray machine that changes
alternating current to direct current. A solenoid is a coil of wire that creates
overlapping force field lines. A sine wave is a wave of electromagnetic radiation.
.A step-down transformer is used in the x-ray circuit to? - ANSWER-A step-down
transformer is used in the x-ray circuit to decrease voltage and increase current flow
to the cathode. This provides the electrons needed for thermionic emission. A
rectifier changes AC to DC.
.An interaction that produces x-rays at the anode as a result of outer shell electrons
filling holes in the K shell is called? - ANSWER-This is a description of characteristic
radiation. Although both characteristic and Brems radiation produce x-rays at the
anode, Brems radiation occurs when a projectile electron misses the outer shell
target electrons and moves close to the nucleus. Photoelectric interaction does
involve outer shell electrons filling holes in the K shell, but it does not produce x-rays
at the anode. Compton interaction produces scatter radiation. ,
.An x-ray machine that makes maximum use of heat loading potential uses a(n): -
ANSWER-A falling load generator allows for very short exposure times by taking
advantage of tube heat-loading potential. When the maximum heat load of the tube
has been reached for a set mA, the generator drops the mA to the next lower level
that the tube can handle (falling heat load). ,
.Atomic mass is represented by the letter? - ANSWER-The letter A is used to
represent atomic mass &which is the number of protons and neutrons. The letter Z
represents atomic number; M and Q are names of an atom's electron shells.
.Atomic number is represented by the letter? - ANSWER-The letter Z represents
atomic number, which is equal to the number of protons. The letter A is used to
, represent atomic mass; M and Q are names of electron shells of an atom.
.Atoms with the same number of protons but with a different number of neutrons
are called? - ANSWER-Isotopes are atoms with the same number of protons but with
a different number of neutrons. Radioactive isotopes are used in nuclear medicine
imaging because they emit gamma rays. In a stable atom the number of protons,
electrons, and neutrons are equal. Ions have too many or too few electrons, not
neutrons.
.Auto-transformers operate on the principle of? - ANSWER-Auto-transformers
operate on the principle of self-induction. These devices need alternating current to
operate. Mutual induction is key to the operation of step-up and step-down
transformers. Current conversion is performed by a rectifier.
.Beam quality is expressed using what unit of measurement? - ANSWER-X-ray beam
quality is expressed numerically by half-value layer, the amount of filtration needed
to reduce the intensity of the beam by half. Gray and mAs are related to x-ray
quantity, not quality.
.Current that flows back and forth is called? - ANSWER-Alternating current (AC) flows
back and forth, whereas direct current (DC) flows in one direction only. A rectified
current would be one that has undergone a change from AC to DC.
.Electron energy is converted to light in what part of the image-intensifier tube? -
ANSWER-Electron energy is converted to light by the output phosphor in amounts 50
to 75 times greater than at the photocathode. At this point, the image is brighter and
smaller. The input phosphor receives exit x-rays from the patient and converts them
into visible light.
