RAD physics final

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RAD physics final
2011-12-07 17:21:19
RAD physics final

RAD physics final
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  1. What applies only to x-rays and gamma rays and their interactions with air?
  2. In what year did Roentgen recieve the Nobel Prize in physics?
  3. Which represents a form of kinetic energy?
    A falling guillotine
  4. What law states that energy can neither be created nor destroyed, but it can change from one form to another?
    Law of conservation of energy
  5. Which of the following is not one of the basic ALARA radiation rules?
    The technologist should hold the patient when necessary
  6. Which of the following is the transfer of energy through space?
  7. Who is responsible for recommending the limits of radiation exposure for radiation workers and the general public?
  8. What year did Roentgen discover x-rays?
  9. Which of the following is the type of x-ray tube that Roentgen was using when he discovered x-light?
    Crookes tube
  10. When ionization occurs, which of the following is true?
    The positive ion is the resulting atom
  11. Which of the following is not an example of electromagnetic radiation capable of ionization?
  12. Which of the following is the largest natural source of radiation exposure man?
  13. What must be applied in order to set a resting body in motion?
  14. What is the unot of power?
  15. Which of the following is the product of force times distance?
  16. What is the unit of radiation absorbed dose?
  17. An AP chest radiograph delivers approx what dose to the patient?
    6 mrad
  18. What is located inside the film cassette on both sides of the film which reduces patient exposure?
    Intensifying screens
  19. Which of the following is not a Cardinal Principal of Radiation?
    Remove filtration
  20. The phosphor that Roentgen employed in early experiments with x-rays was which of the following?
    Barium platinocyanide
  21. Medical x-rays contributes____to man made ionizing radiation
  22. Which of the following is an example of acute radiation injuries?
    Burns and hair loss
  23. Which of the following is the ability to do work by virtue of position?
  24. Which of the following is the principal reason to avoid repeat examinations?
    The patient recieves twice the radiation
  25. A radiation monitoring device would express a technologist's dose equivalent in which of the following?
  26. 1 R=1 rad=?
    1 rem
  27. What is the realitive risk of biological effect caused by radiation?
    Effective dose
  28. Which of the following formulas states Newtons 2nd Law of Motion?
  29. What does ALARA mean?
    As Low As Reasonably Achievable
  30. Which of the following is not capable of ionization?
    Alpha rays and Beta particles
  31. Curie is:
    The unit of quantity of radioactive material
  32. The roentgen is a unit of measure that specifies which of the following?
    The intensity of x-rays
  33. Ionizing radiation is capable of removing____from atoms as it passes through mater
  34. The energy of an x-ray is:
  35. Where were x-rays discovered?
    Wurzburg University
  36. Which of the following provides static x-ray images?
    Digital radiography
  37. Jenny, age 30, is having a x-ray of her pelvis and femur. Which of the following is true?
    Do not use gonadal shields
  38. X-rays and gamma rays are often called?
  39. Which particle has a negative charge?
  40. Which of the followng radioactive processes causes the loss of 4 units of mass and 2 units of positive charge?
    Alpha emission
  41. A stable radioactive atom is a result of:
  42. Who is responsible for the present model of the nuclear atom described as having electrons revolvong around a positively charges nucleus in prescribed energy levels?
    Neils Bohr
  43. Which of the following have the same number of neutrons but different number of protons?
  44. Which of the following shells have the lowest binding energy?
  45. What are the names of the forces that keep an electron in orbit called?
    Centrifugal and Centripetal
  46. The A number is equal to:
    Number of protons and neutrons
  47. Atoms in their natural state are:
    Electrically neutral
  48. When an atom gains an electron or has an electron removed, it is said to be:
  49. What is the maximum number of electrons allowed in the outer shell of an atom?
  50. The smallest particle of an element is:
  51. Any nuclear arrangement is called:
  52. What is the time required for a quantity of radioactivity to be reduces to one half its original value?
    Radioactive half life
  53. When an alpha particle is emiited from the nucleus, it causes the raising of an electron to a higher energy level. This is called?
  54. Which of the following is emitted from outside the nucleus?
  55. The difference between x-rays and gamma rays is:
    Their origin
  56. What are the two principal classes of ionizing radiation?
    Particulate and electromagnetic
  57. What makes up a nucleon?
    Protons and neutrons
  58. When an electron created in the nucleus is ejected from the nucleus with KE amd escapes from the atom causing the Z number to increase by 1 which then changes the element into another, this is known as?
    Beta emission
  59. The reduction of radiation intensity due to scattering and absorbtion is called?
  60. What is one half the range from crest to valley over which a sine wave varies?
  61. X-ray wavelength is:
    Inversely proportional to frequency
  62. The frequency of the wavelength of a sine is:
    The number of valleys that pass per second
  63. When viewing a radiograph, one might properly state:
    Lung tissue is radiolucent
  64. Which of the following do not have mass?
    Photons and electrons
  65. Which of the following has a constant value for all electromagnetic energy?
  66. The wave equation is described as follows:
    Velocity is the product of frequency and wavelength
  67. Which of the following represents a high energy x-ray?
    Short wavelength
  68. If an instrument positioned 1 m from a point source is moved .5m closer to the source, the radiation intensity will:
    Increase by a factor of 4
  69. Which of the following is Planck's constant?
    4.15x10 ^-15 eVs
  70. A small bundle of energy is called?
  71. According to the electromagnetic spectrum, which has the shortest wavelength?
    Gamma rays
  72. X-rays are identified by:
  73. The longer the x-ray photon wavelength, the photon energy is?
  74. X-rays are created at the speed of light and should exist with velocity or do not exist at all according to whose theory?
  75. Electrification occurs through the movement of?
    electrons only
  76. Like charges____and unlike charges____?
    Repel, attract
  77. Electrostatic force is____when the distance between charges is small.
  78. The charges on an electrified object are distributed:
    Evenly throughout the object
  79. On the surface of an electrified object the charges concentrate?
    On the sharpest curvature
  80. What is the unit of electrical potential?
  81. An electric potential applied to a conductor produces a/an
    Electric current and magnetic field
  82. What is Ohms Law?
  83. A charged partice in motion creates a/an
    Magnetic field
  84. Electric power is measured in
  85. Rubber and glass are
  86. When a group of dipoles are aligned they create a
    Magnetic domain
  87. In the United States, an alternating current goes through a complete cycle every _____second
  88. What is the SI unit of magnetic field strength?
  89. Regarding the movement of an electric charge from one atom to another atom:
    Usually outer shell electrons move
  90. What type of material can be made magnetic when placed in an external magnetic field?
  91. Like magnetic poles____and unlike magnetic poles____?
    Repel, attract
  92. The magnetic intensity of an electromagnet is greatly increased by the addition of a/an_____core?
  93. Oersted discovered that an electric current flowing through a wire would affect a ______nearby?
  94. Faraday's experiments proved a current could be induced by a magnetic field only if the field is?
  95. A magnet created by a coil of wire carrying a current is called a
  96. The magnitude of the induced current depends on the
    • angle of the conductor
    • number of turns in the conductor
    • Velocity of the magnetic field as it moves past the conductor
  97. Lenz's law states that an induced current flows in a direction that____the action that produces it
  98. Identify the following
    -------| |-------
  99. An electric current can be induced in a coil of wire if it is placed near a/an
  100. A coil of wire placed and rotated between two poles of a magnet with a strong magnet field to create a current would be an example of an_____?
    Electric generator
  101. A commutator ring is used to change____current to____current in an electric generator?
    AC to DC
  102. The most efficient type of transformer due to the two closed cores is the
    Shell type
  103. The number of windings on the primary side of a step up transformer are always____the number of windings on the secondary side
    Less than
  104. Mechanical motion produces electric current in the
    Electric generator
  105. The two basic types of induction are______induction and_____induction?
    Self and mutual
  106. A transformer converts
    Electric potential to higher and lower intensities
  107. The current to a transformer must be supplied by a/an
    AC source
  108. The electrical resistance of wire decreases as the diameter of the
    wire increases
  109. Allows electrons to flow in only one direction
  110. Momentarily stores electric charge
  111. In an electric generator:
    A coil of wire is rotated in a magnetic field
  112. If DC is applied to the primary coil of a step up transformer, what is the result in the secondary coil?
  113. When designing a transformer, the change in current across it is:
    Inversely proportional to the turns ratio
  114. The electric current produced by an AC generator has:
    Alternating positive and negative intensities
  115. In an induction motor, the only part to be rotated is the:
  116. The main difference between an AC and a DC electric generator is:
    A commutator ring
  117. The x-ray generator with the lowest power rating is the ____imaging system?
    Single phase
  118. The x-ray beam generated by the circuit with the_____voltage ripple has the_____quantity and quality
    lowest, highest
  119. Which of the following converts DC into a series of square pulses?
    Inverter circuit
  120. How many diodes(rectifiers) are needed to produce a full wave rectification?
  121. The autotransformer is used to select which of the following?
    The voltage to the primary side of the step up transformer
  122. The autotransformer has_____winding/s
  123. Variation in power distribution to the x-ray machine are corrected by:
    Line compensator
  124. The filament transformer is designed:
    As a step down transformer
  125. The output voltage from the autotransformer is:
    Proportional to the turns ratio
  126. Which of the following principals of rectification produces the maximum efficiency of x-ray production?
    High frequency
  127. Thermionic emission refers to:
    Electron emission from a heated source
  128. When one uses a step up transformer:
    The secondary voltage will be greater than the primary voltage
  129. In a vacuum tube rectifier, the electron flow is from:
    Cathode to anode only when the anode is positive with respect to the cathode
  130. When designing a transformer, the change in current across it is:
    Inversely proportional to the turns ratio
  131. An automatic exposure control (AEC) device:
    Can employ an ionization chamber between the patient and IR
  132. The automatic exposure control (AEC) terminates the exposure when:
    Sufficient radiation reaches the IR
  133. Which of the following has a multiple waveforms which are superimposed on one another resulting in a waveform that maintains a nearly constant high voltage?
    Three phase power
  134. What is it called when the current flows from the anode to cathode during the nagative phase cycle and causes tube failure?
    Inverse voltage
  135. A solid state diode is a
  136. Which part of the x-ray tube has the target and focal spot?
  137. Most x-ray tubes used for radiography:
    Are dual focus tubes
  138. The main reason for employing the line focus principal is to:
    Improve spatial resolution and heat capacity
  139. X-ray intensity is lower on the anode side than on the cathode side because of which of the following?
    X-ray absorbtion in the target
  140. When electrons strike the target of an x-ray tube, _____of their KE is converted to heat
  141. Which of the following is not a function of the anode?
    Thermionic emission
  142. The effective focal spot is:
    Smaller than the actual focal spot
  143. The small craters in the target of the anode of an x-ray tube are known as what?
  144. The protective housing is used to:
    • prevent shock
    • prevent unnecessary radiation from escaping
    • redces the level of unnecessary radiation to 100mR/hr at maximal conditions
  145. X-rays are emitted:
  146. As the x-ray tube ages, the inside can become coated with tungsten, which can cause____in the tube
  147. Thermionic emission does not occur until a current of:
    4 A
  148. What is the term for the electrons that bounce off the focal spot and land on other areas of the target causing x-rays to be produced?
    Off focus radiation
  149. What is it called when an increase in voltage to the filament does not result in higher mA because all of the electrons have been used?
    Saturation Current
  150. A break in the filament is called:
  151. X-rays that escape through the protective housing and contribute to unnecessary radiation are called?
    Leakage radiation
  152. A high frequency generator has a____voltage ripple?
  153. What is the purpose of a window in an x-ray tube?
    For the emission of x-rays
  154. Proectile electrons travel from:
    Cathode to anode
  155. During an exposure, most of the____energy of the projectile electrons is converted to______?
    Kinetic, heat
  156. Which shell level has the greatest binding energy?
  157. Electron interaction at the inner shell of the target atoms produces_____radiation
  158. The farther to the right a x-ray emission spectrum is the:
    higher the quality of the x-ray beam
  159. The producion of heat at the anode is directly proportional to:
    Tube current
  160. The useful characteristic x-rays from tungsten targets are_____x-rays.
  161. A Bremsstrahlung x-ray is produced when:
    Projectile electron interacts with the nuclear electrical field of the target atom
  162. Characteristic k-shell x-rays have an effective energy of_____keV?
  163. _____is when an electron moves from a lower energy level to a higher energy level?
  164. An increase in mAs would_____the_____of the emission spectrum?
    increase, amplitude only
  165. The ______of an x-ray beam is higher when a peak of the emission spectrum is further to the______
    Quality, right
  166. The HVL is an expression of the____of an x-ray beam?
  167. Which of the following spectrums have fixed energies and form a discrete emission spectrum?
  168. An increase in kV would____the_____of the emission spectrum?
    Increase, position and amplitude
  169. Due to the realitive increase in average energy as a result of added filtration, the x-ray beam sometimes becomes:
  170. The discrete portion of the x-ray emission spectrum would change position with a change in:
    Target material
  171. If you increase the kVp, you increas?
    Electron KE
  172. The amplitude of the emission spectrum is_____with a_____generator than/as with a three phase generator?
    lower, single phase
  173. Which of the following produces the lowest voltage ripple?
    High frequency
  174. Useful characteristc x-rays are produced in tungsten:
    by ionization of a k-shell electron
  175. When the characteristic x-rays are produced, the characteristic energy has energy:
    Equal to the difference in the electron binding energies
  176. The electrons flowing across the tube from cathode to anode constitutes a/an
    tube current
  177. How does added filtration affect the emission spectrum?
    Decreases the amplitude and shifts to the right
  178. The area under the curve of the x-ray emission spectrum represents:
    the total number of x-rays emitted
  179. The number of useful x-rays in the beam defines x-ray:
  180. X-ray quantity increases in direct prportion to increases in______
  181. Which of the following factors primarily affects the low energy side of the x-ray emission spectrum?
  182. A diagnostic imaging system operated at 80kVp/200mA/100ms with a tungsten target. How would the total emission spectrum be effected by operation at 80kVp/400mA/100ms? The realitive position of the spectrum would?
    Remain the same, but the amplitude would increase
  183. If filter thickness____, then x-ray intensity is_____
    Decreased, increased
  184. What is a commonly used filter?
  185. What is the thickness of an absorbing material necessary to reduce an x-ray beam to half its original value?
  186. Which is a higher energy level when compared to the L shell?
    M shell
  187. Which of the following is the filtration of the useful beam provided by the x-ray tube housing and window?
    Inherent filtration
  188. What is the total filtration?
  189. To maintain a film's constant optical density, a technique requires
    15% increase kVp and 1/2 decrease in mAs
  190. What is x-ray intensity measured in?
  191. When distance is increased, x-ray quantity at that distance:
    decreased in proportion to distance squared
  192. The penetrability of the x-ray beam is called the x-ray
  193. If increasing the kVp, increases the HVL, x-ray quality will:
  194. A compensatng filter is used to create_____optical density with a body part of_____thickness
    Uniform, non uniform
  195. Inherent filtration:
    Increases with tube age
  196. A low quality beam would also have low:
  197. An x-ray beam that could pass throgh dense tissue would have high____
  198. The main purpose of added filtration is to reduce_____
    patient dose