©THESTAR 2024/2025 ALL RIGHTS RESERVED 11:09PM. A+
Chapter 2: Radiation Physics Exam Questions
With Correct Answers 100% Verified.
Absorption - Answer✔Refers to the total transfer of energy from the x-ray photon to the atoms
of matter through which the x-ray beam passes. And depends on the energy of the x-ray beam
and the composition of the absorbing matter of tissues
Alpha particles - Answer✔These are emitted from the nuclei of heavy metals and exist as 2
protons and neutrons, without electrons
Aluminum disks - Answer✔sheets of 0.5mm thick aluminum placed in the path of the x-ray
beam—filter out the non-penetrating, longer wavelength x-rays
Amperage - Answer✔the measurement of the number of electrons moving through a
conductor
Ampere (A) - Answer✔Current is measured in this or in miliamperes (mA)
Anode - Answer✔positive electrode, consist of a wafer-thin tungsten plate embedded in a solid
copper rod.
Atom - Answer✔The fundamental unit of matter
Neutral atom - Answer✔An atom that contains an equal number of protons (positive charges)
and electrons (negative charges).
Atomic number - Answer✔The number of protons inside the nucleus equals the number of
electrons outside the nucleus and determines this.
Atomic weight - Answer✔The number of protons and neutrons in the nucleus of an atom
determines this or the mass number
Autotransformer - Answer✔serves as a voltage compensator that corrects for minor
fluctuations in the current.
Beta particles - Answer✔Fast moving electrons emitted from the nucleus of radioactive atoms
1
, ©THESTAR 2024/2025 ALL RIGHTS RESERVED 11:09PM. A+
Binding energy - Answer✔Also known as binding force of an electron
-This is determined by the distance between the nucleus and the orbiting electron and is
different for each shell.
-The strongest of these is found closest to the nucleus in the K shell, whereas electrons located
in the outer shells have a weak binding energy.
Bremsstrahlung (braking radiation) - Answer✔A form of radiation that occurs when speeding
electrons slow down because of their interactions with the tungsten target in the anode also
known as general radiation
Cathode - Answer✔Negative electrode, consists of a tungsten wire filament in a cup-shaped
holder made of molybdenum
Cathode ray - Answer✔streams of high-speed electrons that originate in an x-ray tube
Circuit - Answer✔a path of electrical current.
Filament Circuit - Answer✔The circuit that regulates the flow of electrical current to the
filament of the x-ray tube; controlled by the miliampere settings (also known as low-voltage
circuit)
High-voltage circuit - Answer✔The circuit that provides the high voltage required to accelerate
electrons and to generate x-rays in the x-ray tube; controlled by the kilovoltage settings
Coherent scatter - Answer✔Another type of scatter radiation that may take place when x-rays
interact with matter is known as this or unmodified scatter. This type of radiation involves an x-
ray photon that has its path altered by matter. This occurs when a low-energy x-ray photon
interacts with an outer-shell electron. No change in the atom occurs, and an x-ray photon of
scattered radiation is produced.
Compton electron - Answer✔The x-ray photon loses energy and continues in a different
direction (scatters) at a lower energy level. The new, weaker x-ray photon interacts with other
atoms until all its energy is gone. The ejected electron is termed this or recoil electron, and has
a negative charge. The remaining atom is positively charged.
Compton scatter - Answer✔An x-ray photon collides with a loosely bound, outer shell electron
and gives up part of its energy to eject the electron form its orbit.
Control panel - Answer✔Panel contains an on-off switch and an indicator light, an exposure
button and indicator light, and control devices (time, kilovoltatge, and milliamperage slectors)
to regulate the x-ray beam.
Copper stem - Answer✔which functions to dissipate the heat away from the tungsten target.
2
, ©THESTAR 2024/2025 ALL RIGHTS RESERVED 11:09PM. A+
Alternating Current (AC) - Answer✔describes an electrical current in which the electrons flow in
2, opposite directions
Direct Current (DC) - Answer✔Electrical current is termed this when the electrons flow in one
direction through the conductor
Electrical current - Answer✔Electrical energy consists of a flow of electrons through a
conductor; this flow is known as this
Electricity - Answer✔energy that is used to make x-rays.
Electromagnetic spectrum - Answer✔Electromagnetic radiations are arranged according to
their energies in what is termed this type of spectrum
Electron - Answer✔Tiny, negatively charged particles that have very little mass.
Weighs approximately 1/1800 as much as a proton or neutron.
Electron volt (eV) - Answer✔The binding energies of orbital electrons are measured in this or
kilo electron volts (keV)
Electrostatic force - Answer✔Electrons are maintained in their orbits by this force or attraction,
between the positive nucleus and the negative electrons.
Element - Answer✔Substances made up of only one type of atom
Energy - Answer✔When matter is altered
Extension arm - Answer✔A part of the dental x-ray machine; suspends the x-ray tubehead and
houses electrical wires that extend from the control panel to the tubehead.
Frequency - Answer✔Refers to the number of wavelengths that pass a given point in a certain
amount of time
Insulating oil - Answer✔The oil that surrounds the x-ray tube and transformers inside the
tubehead -prevents overheating by absorbing the heat created by the production of x-rays.
Ion - Answer✔An atom that gains or loses an electron and becomes electrically unbalanced
Ion pair - Answer✔Results when an electron is removed from an atom in the ionization process.
The atom becomes the positive ion, and the ejected electron becomes the negative ion. This
structure reacts with other ions until electrically stable, neutral atoms are formed
Ionization - Answer✔The production of ions, or the process of converting an atom into ions
Kilo electron volt (keV) - Answer✔The binding energies of orbital electrons are measured in this
or electron volts (eV)
3
Chapter 2: Radiation Physics Exam Questions
With Correct Answers 100% Verified.
Absorption - Answer✔Refers to the total transfer of energy from the x-ray photon to the atoms
of matter through which the x-ray beam passes. And depends on the energy of the x-ray beam
and the composition of the absorbing matter of tissues
Alpha particles - Answer✔These are emitted from the nuclei of heavy metals and exist as 2
protons and neutrons, without electrons
Aluminum disks - Answer✔sheets of 0.5mm thick aluminum placed in the path of the x-ray
beam—filter out the non-penetrating, longer wavelength x-rays
Amperage - Answer✔the measurement of the number of electrons moving through a
conductor
Ampere (A) - Answer✔Current is measured in this or in miliamperes (mA)
Anode - Answer✔positive electrode, consist of a wafer-thin tungsten plate embedded in a solid
copper rod.
Atom - Answer✔The fundamental unit of matter
Neutral atom - Answer✔An atom that contains an equal number of protons (positive charges)
and electrons (negative charges).
Atomic number - Answer✔The number of protons inside the nucleus equals the number of
electrons outside the nucleus and determines this.
Atomic weight - Answer✔The number of protons and neutrons in the nucleus of an atom
determines this or the mass number
Autotransformer - Answer✔serves as a voltage compensator that corrects for minor
fluctuations in the current.
Beta particles - Answer✔Fast moving electrons emitted from the nucleus of radioactive atoms
1
, ©THESTAR 2024/2025 ALL RIGHTS RESERVED 11:09PM. A+
Binding energy - Answer✔Also known as binding force of an electron
-This is determined by the distance between the nucleus and the orbiting electron and is
different for each shell.
-The strongest of these is found closest to the nucleus in the K shell, whereas electrons located
in the outer shells have a weak binding energy.
Bremsstrahlung (braking radiation) - Answer✔A form of radiation that occurs when speeding
electrons slow down because of their interactions with the tungsten target in the anode also
known as general radiation
Cathode - Answer✔Negative electrode, consists of a tungsten wire filament in a cup-shaped
holder made of molybdenum
Cathode ray - Answer✔streams of high-speed electrons that originate in an x-ray tube
Circuit - Answer✔a path of electrical current.
Filament Circuit - Answer✔The circuit that regulates the flow of electrical current to the
filament of the x-ray tube; controlled by the miliampere settings (also known as low-voltage
circuit)
High-voltage circuit - Answer✔The circuit that provides the high voltage required to accelerate
electrons and to generate x-rays in the x-ray tube; controlled by the kilovoltage settings
Coherent scatter - Answer✔Another type of scatter radiation that may take place when x-rays
interact with matter is known as this or unmodified scatter. This type of radiation involves an x-
ray photon that has its path altered by matter. This occurs when a low-energy x-ray photon
interacts with an outer-shell electron. No change in the atom occurs, and an x-ray photon of
scattered radiation is produced.
Compton electron - Answer✔The x-ray photon loses energy and continues in a different
direction (scatters) at a lower energy level. The new, weaker x-ray photon interacts with other
atoms until all its energy is gone. The ejected electron is termed this or recoil electron, and has
a negative charge. The remaining atom is positively charged.
Compton scatter - Answer✔An x-ray photon collides with a loosely bound, outer shell electron
and gives up part of its energy to eject the electron form its orbit.
Control panel - Answer✔Panel contains an on-off switch and an indicator light, an exposure
button and indicator light, and control devices (time, kilovoltatge, and milliamperage slectors)
to regulate the x-ray beam.
Copper stem - Answer✔which functions to dissipate the heat away from the tungsten target.
2
, ©THESTAR 2024/2025 ALL RIGHTS RESERVED 11:09PM. A+
Alternating Current (AC) - Answer✔describes an electrical current in which the electrons flow in
2, opposite directions
Direct Current (DC) - Answer✔Electrical current is termed this when the electrons flow in one
direction through the conductor
Electrical current - Answer✔Electrical energy consists of a flow of electrons through a
conductor; this flow is known as this
Electricity - Answer✔energy that is used to make x-rays.
Electromagnetic spectrum - Answer✔Electromagnetic radiations are arranged according to
their energies in what is termed this type of spectrum
Electron - Answer✔Tiny, negatively charged particles that have very little mass.
Weighs approximately 1/1800 as much as a proton or neutron.
Electron volt (eV) - Answer✔The binding energies of orbital electrons are measured in this or
kilo electron volts (keV)
Electrostatic force - Answer✔Electrons are maintained in their orbits by this force or attraction,
between the positive nucleus and the negative electrons.
Element - Answer✔Substances made up of only one type of atom
Energy - Answer✔When matter is altered
Extension arm - Answer✔A part of the dental x-ray machine; suspends the x-ray tubehead and
houses electrical wires that extend from the control panel to the tubehead.
Frequency - Answer✔Refers to the number of wavelengths that pass a given point in a certain
amount of time
Insulating oil - Answer✔The oil that surrounds the x-ray tube and transformers inside the
tubehead -prevents overheating by absorbing the heat created by the production of x-rays.
Ion - Answer✔An atom that gains or loses an electron and becomes electrically unbalanced
Ion pair - Answer✔Results when an electron is removed from an atom in the ionization process.
The atom becomes the positive ion, and the ejected electron becomes the negative ion. This
structure reacts with other ions until electrically stable, neutral atoms are formed
Ionization - Answer✔The production of ions, or the process of converting an atom into ions
Kilo electron volt (keV) - Answer✔The binding energies of orbital electrons are measured in this
or electron volts (eV)
3
