Deck 2: Radiation Physics

Question 1

Cathode rays are derived from which of the following types of particulate radiation?

A)Electrons
B)Alpha particles
C)Protons
D)Neutrons

Answer 1

Electrons

Question 2

An ion pair results when

A)a proton is removed from an atom.
B)an electron is removed from an atom.
C)a neutron is removed from an atom.
D)two atoms share a pair of electrons.

Answer 2

an electron is removed from an atom.

Question 3

Which subatomic particle carries a negative electrical charge?

A)A neutron
B)A proton
C)An electron
D)A nucleon

Answer 3

An electron

Question 4

The binding energy or binding force of an electron is

A)determined by the distance between the neutrons and protons within the nucleus.
B)determined by the distance between the orbiting electrons and the nucleus.
C)weaker for electrons located in inner shells than in outer shells.
D)determined by the atomic number.

Question 5

The spontaneous emission of radiation from the disintegration of unstable atomic nuclei is

A)beta particle decay.
B)radiation.
C)radioactivity.
D)alpha particle decay.

Question 6

Heat is a byproduct of x-ray production.Which component of the x-ray tubehead dissipates the heat created by the production of x-rays?

A)Metal housing
B)Insulating oil
C)Aluminum discs
D)Lead collimator

Question 7

Electromagnetic radiations

A)are entirely human-made.
B)include x-rays and visible light.
C)are a form of particulate radiation.
D)have mass.

Question 8

Your patient had x-rays taken in her previous dental office.She notices that the long metal tube at the end of the x-ray head is longer than it was at the other office.What explanation would you give for the purpose of the tube,or cone,attached to the x-ray head?

A)It surrounds the x-ray tube,protects the x-ray tube,and grounds the high-voltage components.
B)It seals the oil in the tubehead and acts as a filter to the x-ray beam.
C)It filters out the nonpenetrating,longer-wavelength x-rays.
D)It aims and shapes the x-ray beam.

Question 9

Which of the following forms of electromagnetic radiation are capable of ionization?

A)Radio waves
B)Visible light
C)Ultraviolet light
D)X-rays

Question 10

Which of the following statements is true of ionization?

A)An atom that gains an electron will have a negative charge.
B)An atom that loses an electron will have a negative charge.
C)An atom that loses an electron will have a positive charge.
D)An atom that gains an electron has a negative charge,and an atom that loses an electron has a positive charge.

Question 11

Photons are

A)bundles of energy with mass and weight.
B)bundles of energy that travel at the speed of sound.
C)a component of the particle concept of electromagnetic radiation.
D)a component of the wave concept of electromagnetic radiation.

Question 12

(1)Radiation is the emission and propagation of energy through space or a substance in the form of waves or particles.(2)Radioactivity can be defined as the process by which certain unstable atoms or elements undergo spontaneous disintegration,or decay,in an effort to attain a more balanced nuclear state.

A)Both statements are true.
B)Both statements are false.
C)The first statement is true;the second statement is false.
D)The first statement is false;the second statement is true.

Question 13

Which of the following statements is true of orbits or shells in the atom?

A)Protons travel around the nucleus in well-defined shells.
B)An atom contains innumerable shells.
C)The energy level within each shell is the same.
D)The orbiting shell closest to the nucleus has the highest energy level.

Question 14

Which of the following components of the x-ray machine would have two indicator lights?

A)X-ray tube
B)X-ray tubehead
C)The control panel
D)The extension arm

Question 15

Which of the following statements is true of ionizing radiation?

A)It is radiation that is capable of producing ions by removing or adding an electron to an atom.
B)It is strictly an electromagnetic radiation and does not involve particles that have mass.
C)It is strictly particulate radiation and cannot travel as waves.
D)It can only travel at the speed of light.

Question 16

The fundamental unit of matter is the

A)proton.
B)neutron.
C)electron.
D)atom.

Question 17

The nucleus of an atom contains

A)protons.
B)neutrons.
C)protons and neutrons.
D)electrons.

Question 18

Which of the following statements is true of the wave concept of electromagnetic radiation?

A)Wavelength refers to the speed of the wave.
B)Velocity refers to the number of wavelengths that pass a given point in a certain amount of time.
C)Frequency is defined as the distance between the crest of one wave and the crest of the next.
D)Frequency and wavelength are inversely related.

Question 19

Which of the following forms of electromagnetic radiation has the shortest wavelength?

A)Radio wave
B)Television wave
C)Radar wave
D)Dental x-ray wave

Question 20

Which of the following elements is the simplest atom?

A)Hydrogen (H #1)
B)Helium (He #2)
C)Nitrogen (N #7)
D)Oxygen (O #8)

Question 21

Your x-ray machine runs off 110 volts.Theoretically what would occur if there was no step-down transformer in the x-ray control panel?

A)Too few electrons would be produced for the purpose of dental x-rays.65,000 to 100,000 volts are required to heat the tungsten filament.
B)Too few electrons would be produced for the purpose of dental x-rays.50,000 to 75,000 volts are required to heat the tungsten filament.
C)Too many electrons would be produced for the purpose of dental x-rays.Only 3-5 volts are required to heat the tungsten filament.
D)There would be no interruption in function of the machine.

Question 22

Which would you adjust if you wanted to produce characteristic radiation?

A)Milliamperage
B)Kilovoltage
C)Step-up transformer
D)Step-down transformer

Question 23

Within the x-ray tube,electrons are generated by the

A)tungsten filament in the cathode.
B)tungsten filament in the anode.
C)molybdenum cup.
D)copper stem.

Question 24

The lead collimator

A)carries away the heat produced during the production of x-rays.
B)permits a small number of x-rays to exit from the x-ray tube.
C)filters the longer-wavelength x-rays from the beam.
D)restricts the size of the x-ray beam.

Question 25

In the dental x-ray tube,the number of electrons created is controlled by

A)alternating current.
B)direct current.
C)milliamperage.
D)kilovoltage.

Question 26

The purpose of the anode is to

A)produce electrons when heated.
B)convert electrons into x-ray photons.
C)absorb heat created by the production of x-rays.
D)filter out nonpenetrating,longer-wavelength x-rays.

Question 27

Which form of the x-ray beam is most detrimental to the patient and operator?

A)Primary radiation
B)Secondary radiation
C)Scatter radiation
D)Useful beam

Question 28

Which property of x-rays allows for the image on the receptor?

A)Fluorescence
B)Penetrating power
C)Focusing capability
D)Effect on living tissue

Question 29

Which of the following statements is true of characteristic radiation?

A)It is also known as braking (bremsstrahlung)radiation.
B)It only occurs at 70 kV and above.
C)It is the source of the majority of x-rays that are produced.
D)The high-speed electron passes close to the nucleus or hits the nucleus of the tungsten atom.

Question 30

Which is the most common possibility when an x-ray photon interacts with matter?

A)No interaction
B)Absorption or photoelectric effect
C)Compton scatter
D)Coherent scatter

Question 31

Thermionic emission of electrons occurs at the

A)tungsten filament in the anode.
B)tungsten filament in the cathode.
C)copper stem.
D)molybdenum cup.

Question 32

Which would you adjust if you wanted to create a larger electron cloud?

A)Milliamperage
B)Kilovoltage
C)Step-up transformer
D)Step-down transformer

Question 33

Approximately what percentage of the kinetic energy of the electrons is converted to x-rays at the anode?

A)Less than 1%
B)25%
C)50%
D)100%

Question 34

Which of the following four possibilities that can occur when an x-ray photon interacts with matter is responsible for producing densities on a dental receptor that make dental radiography possible?

A)No interaction
B)Absorption or photoelectric effect
C)Compton scatter
D)Coherent scatter

Question 35

Interaction with the x-ray photon as a result of the photoelectric effect is harmful to the patient because ionization occurs.

A)The statement is true.
B)The statement is false.
C)The first part of the statement is true,but the second part of the statement is false.
D)The first part of the statement is false,but the second part of the statement is true.

Question 36

(1)X-ray photon production occurs as a result of both general and characteristic radiation.(2)General radiation accounts for a small number of x-ray photons produced because it takes high kV to dislodge the electrons from the K shell.

A)Both statements are true.
B)Both statements are false.
C)The first statement is true;the second statement is false.
D)The first statement is false;the second statement is true.