Physics

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Physics
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  1. Standard unit for length?
    meter
  2. What is an electromagnet?
    a coil of wire that carries current & has a core of iron inserted in its center to increase magnetic strength
  3. What is true about the interactions between the lines of force & a single loop conductor?
    1. the stronger the magnetic field, the higher the induced voltage

    2.if the number of turns in the conductor is increased, the induced voltage increases
  4. The physical contact of two or more non-insulated wires carrying current will result in a?
    short circuit
  5. Give the 3 ways to induce a voltage in a wire by electromagnetic induction?
    1. the conduction can move through a magnetic field

    2.the magnetic field can move past the conduction

    3.the strength of the magnetic field can change
  6. Solenoid?
    helix coil of wire that carries a current
  7. Any materials which tend to oppose the flow of electrons are termed?
    1. non-conductors

    2.Insulators
  8. What devices are used for the storage of electricity?
    • 1. capacitor
    • 2.condenser
    • 3.battery
  9. Velocity of all electromagnetic radiation in a vacuum is?
    3x10^10cm/sec or 3x10^8m/s
  10. The resistance of a wire is related to its?
    1. length

    2.temperature

    3.cross-sectional area
  11. The magnetic force lines or lines of flux in a magnetic field flow?
    1. within the magnet itself

    2. outside the magnet
  12. The amount of electrical potential, or potential difference in an electrical circuit, is measured by a unit called?
    volt
  13. The electrical discharge that occurs between 2 oppositely charged objects, when the insulating properties of the transfer medium is exceeded is called?
    static
  14. Si unit for magnetic field strength is?
    Tesla
  15. An electromagnetic device consists of a single iron core surrounded by a wire carrying current is?
    electromagnet
  16. The type of electricity associated w/the flow of current in a single direction is termed?
    direct current
  17. A hydrogen atom, orbital electron, & Iron atom are all associated w/ what?
    magnetic moment (field)
  18. A circuit which has 6.3x 10^18 electrons flowing per sec is said to have a current of/
    one ampere
  19. The power of a circuit is equal to the product of current & voltage & is measured by what unit?
    watt
  20. The resistance of a wire will increase as what increases?
    • 1. length
    • 2.temperature
    • 3diameter
  21. The force within an electric circuit most responsible for the movement of current is termed?
    potential difference
  22. The magnetic dipole resulting from the proton spin in a hydrogen nucleus is termed?
    magnetic moment
  23. The laws of magnetism are similar to the laws of electrostatic bc they both?
    are produced by the same physical process
  24. The frequency (hertz) of an electromagnetic wave is best defined as?
    number of oscillations or cycles per sec
  25. In a solid conductor, current consists of a flow of moving?
    electrons
  26. A commonly used device used in the detection of a magnetic field is?
    compass
  27. flux?
    magnetic field lines
  28. The electrical resistance which occurs in a conductor is most often manifested as the amount of _______ created?
    heat
  29. Have the ability to deflect the path of an electromagnetic photon beam?
    strong gravitational field
  30. n a magnet the individual magnetic domains are aligned in?
    single direction
  31. The principle of electromagnetic induction is based upon experiments show that whenever a conductor cuts across magnetic flux?
    an EMF is induced
  32. Electrification may occur from what processes?
    • 1. conduction
    • 2. friction
  33. The total current through each resistor is the same for all parts of the series circuit? T or F?
    true
  34. Magnetic fields are a phenomenon associated with?
    moving charges
  35. Heta is a form of electromagnetic radiation produced at relatively low energies called?
    Infrared radiation
  36. What units are used to measure the magnetic flux density?
    Tesla or gauss
  37. Give an example of an artificial permanent magnet?
    bar magnet, compass
  38. The strong magnetic dipole of a hydrogen atom is due in large part to?
    unpaired orbital electron
  39. Which members of the electromagnetic spectrum will normally have photon wavelengths longer than those of diagnostic xray photons?
    1. infrared

    2.microwaves
  40. Which type of radiation possesses sufficient energies to cause ionization?
    X-rays
  41. The production of electricity by the rotation of a coil of wire within a stationary magnetic field is termed?
    electromagnetic induction
  42. What is true of both 100keV x-rays & 10 keV gamma ray?
    they have 0 mass
  43. The transfer of same charge to an uncharged object by placing the 2 objects in contact with eachother is termed?
    conduction
  44. Amplitude of a sine wave is its?
    min to max
  45. The frequency of a sine wave is?
    number of valleys that pass per second (# of wavelengths per sec)
  46. Electromagnetic radiation exists at?
    the speed of light or not at all (3x10^8 m/s)
  47. Inverse square law is a result of?
    divergence
  48. The equivalence of mass & energy is described by?
    Einstein's theory
  49. Dipole?
    the magnetic field of a single electron
  50. Paramagnetic?
    weekly magnetic
  51. Which will induce an EMF of the greatest magnitude? 
    A) conductor cutting flux @ 45 degree angle
    or
    B) conductor cutting flux @ a 90 degrees angle
    Conductor cutting flux @ a 90 degree angle
  52. A ____ ______ always surrounds a conductor in which a current is flowing?
    magnetic field
  53. A magnet's electrons spin predominantly in ______ directions?
    the same
  54. State(2) of the 3 laws of magnetism?
    • 1. like poles repel, opposites attract
    • 2.every magnet has a N & S pole
    • 3.the farther apart the magnets are the weeker the field strength
  55. The principle difference between an xray photon & a gamma ray is?
    region in the atom from where the photon originates
  56. Sunburn is common reaction to overexposure to a normal component of sunlight called?
    ultraviolet radiation
  57. Partial absorption of energy by any form of matter is?
    attenuation
  58. Energy of an electromagnetic radiation is directly proportional to?
    frequency of the radiation
  59. Xray wavelength has what type of relationship w/ frequency?
    Inversely proportional
  60. A single unit of electromagnetic radiation is also called?
    a photon
  61. What has a constant value for all electromagnetic radiation?
    velocity
  62. Velocity of light is?
    3x10^10 cm/s (3x10^8 meters or speed of light)
  63. The principal difference between xrays & gamma rays is their?
    origin
  64. Ferromagnetic?
    strongly magnetic
  65. Give example of a natural magnet?
    the earth
  66. If a metal is easy to magnetize, it will be _____ to demagnetize?
    easy
  67. Magnetic lines of force exit the ______ pole, curve around the surrounding space & are directed towards the ____ pole?
    North; South
  68. Glass, when placed in a magnetic field, will distort the lines of flux? T or F?
    false
  69. The two types of electrical charges are derived from their corresponding charged atomic particles called?
    electrons & protons
  70. The rubbing of fur & amber or silk w/glass result in electrification by a process called?
    friction
  71. According to the 1st law of electrostatics, 2 objects with opposite charges will tend to?
    attract eachother
  72. An object with a net positive charge can be described as having a deficiency of?
    electrons
  73. A major source of electrical current which is produced by a chemical process is a?
    battery
  74. Give examples of a natural magnet?
    • 1.lodestone
    • 2.earth
  75. Which of the following is true concerning the energy of electromagnetic radiation?
    the energy of a wave will increase as its frequency increases
  76. All electromagnetic radiations produce a type of variation in space known as?
    sine wave
  77. Member of the electromagnetic spectrum possessing a wavelength of 700 nanometers is?
    red light
  78. The wave equation is described as?
    wavelength is velocity divided by frequency
  79. The law which relates to the relative amperage, voltage & resistance in a direct current circuit is?
    Ohm's law
  80. The dual wave & particle natures of electromagnetic radiation was 1st proposed by?
    Quantum theory
  81. Domain?
    many atoms aligned to produce a larger magnetic field
  82. Retentivity?
    a magnets ability to resist demagnetization
  83. Magnetism is the ability of a material to attract _______, ______, and _______?
    Iron,cobalt, & nickel
  84. Permeability?
    the ease with which a material can be magnetized
  85. Give examples of materials with a high electrical resistance?
    1. rubber

    2.wood
  86. An electromagnetic device which converts mechanical into electrical energy is termed?
    generator
  87. The electrostatic force between 2 charged objects is ________ proportional to the product of their magnitudes?
    directly
  88. Give examples of electrical conductors?
    1. copper

    2.water
  89. According to the principle stated in coulombs law, the electrostatic force between 2 charged objects is _____ proportional to the ______ of the distance between them?
    Inversely, square
  90. The electromagnetic spectrum contains what & scales?
    1. energy

    2.frequency

    3.wavelength
  91. Properties of electromagnetic energy photons include?
    • 1.frequency
    • 2. wavelength
    • 3.velocity
    • 4. amplitude
  92. 3 wave parameters?
    • 1. velocity
    • 2.frequency 
    • 3.wavelength
  93. Frequency range of electromagnetic energy is?
    electromagnetic spectrum
  94. Electromagnetic force?
    one of the 4 basic forces in the universe
  95. Frequency is? Measured in?
    the wave's rate, Hertz(Hz)
  96. Transmission is?
    x-rays traveling all the way through
  97. Photons have what?
    magnetic & electrical fields that continuously change
  98. SI unit of charge?
    Coulomb(C)
  99. Electric charges come in units that are?
    positive or negative
  100. Electromagnetic spectrum extends from what to what?
    approximately 10^2 to 10^24 Hz
  101. Electrification can be created by?
    • 1. friction
    • 2. contact
    • 3.Induction
  102. Electrification by friction occurs by?
    rubbing electrons off one object &depositing them on another
  103. When the charged body confers the opposite kind of charge on the metallic body this is known as?
    Induction
  104. The ease at which a material can be penetrated by a magnetic field?
    permeability
  105. Unit for electrical charge is?
    Coulomb
  106. When iron is fabricated into a magnet the magnetic domains do what?
    align
  107. When iron is brought near a permanent magnet, the lines of the magnetic field are?
    attracted to the iron
  108. 2 types of waves?
    1. transverse 

    2. longitudinal (compressional)
  109. Electrical continuum is?
    an uninterrupted ordered sequence
  110. What happens to amplitude as waves spread out?
    it drops; they lose height as they spread
  111. Sound waves amplitude translates into?
    volume & loudness
  112. What is amplitude for sound wave?
    maximum displacement of molecules in a compression or in an expansion from where they would be if the air were undisturbed
  113. One (Hz) Hertz is equal to?
    1 cycle per sec
  114. Photons have no?
    mass
  115. What is the speed of speed of light?
    c=3x10^8m/s
  116. Electromagnetic energy exists in a larger range called?
    electrical continum
  117. In xrays amplitude relates to?
    intensity of the beam
  118. Amplitude is what?
    max distance of a single trough or crest from the undisturbed water level
  119. Velocity is? Measured in?
    Speed of wave; meters per sec
  120. Wavelength is? Measured in?
    length of wave; meters
  121. The decrease in intensity is ______ proportional to the square of the distance of the object from the source?
    inversley
  122. Various types of energy on the electromagnetic spectrum are similar how? How are they different?
    Same photons; frequency & wavelength
  123. Particle model=
    Quantum theory
  124. Xrays are identified by? Measured in?
    Intensity of beam; electron volts
  125. Magnetic & electrical field are _______ to eachother?
    perpendicular
  126. Any electrically charged particle which is moving generates what? Along with?
    magnetic field; electrical field
  127. 3 parameters of sine wave are?
    1. wavelength

    2. frequency

    3.Amplitude
  128. One completion of the wave b4 it repeats itself?
    cycle
  129. Primary function of an xray imaging system is?
    convert electric energy into electromagnetic energy
  130. SI unit of magnetic field strength? An older unit is?
    Tesla; gauss
  131. Magnetic classifications of matter are?
    • nonmagnetic
    • farromagnetic
    • paramagnetic
    • diamagnetic
  132. Accumulation of many atomic magnets w/their dipoles aligned creates?
    magnetic domain
  133. Small magnet created by the electron orbit is called?
    magnetic dipole
  134. 2 ways to get higher frequency?
    • shorter wavelengths
    • traveling at faster speeds
  135. Xray energies range from what to what?
    10 kev-50mev
  136. 4 measurable qualities all waves have?
    • amplitude
    • frquency
    • speed 
    • wavelength
  137. Electrostatics?
    study of stationary electric charges
  138. Frequency of a series of waves will depend upon what? why?
    • speed of the waves & wavelengths
    • they are all interrelated
  139. Magnetic field is proportional to the product of?
    magnetic poles strengths divided by the square of the distance between them
  140. Velocity of the waves will always equal?
    the product of their frequency x their wavelengths
  141. Special quantities? Def. & examples?
    supports measurement in specialized areas of science & tech

    • EX:
    • 1. exposure
    • 2.dose
    • 3. radioactivity
  142. Matter?
    Anything that has shape of form & occupies space
  143. Compound?
    substance in which atoms of different elements are chemically bound together
  144. Derived quantities are? Def. & examples?
    • Derived from one or more of the 3 base quantities
    • Ex:
    • 1. volume
    • 2.speed/velocity
  145. Dalton Atom
    • ~composed of identical atoms that react the same way chemically
    • ~Has "hooks" & "eyes"
  146. Atomic mass # is what? What letter represents it?
    • *Always a whole number*
    • number of photons plus neutrons
    • A
  147. Base quantities are? Give Def. & examples?
    • standard unit of measurement
    • Ex: 
    • 1.length
    • 2.mass
    • 3.time
  148. A neutral atom that loses an electron by ionization is?
    positive ion
  149. Photons produced during the orbital transitions of electrons from higher to lower energy are termed?
    Characteristic radiations
  150. Formation of molecules can be accomplished through the interaction of valence electrons by a process called?
    • Ionic bonding (giving away)
    • Covalent bonding (sharing)
  151. Which state of matter cprresponds to the highest degree of molecular attraction?
    solid
  152. Most chemically stable elements having a filled outer shell configuration are termed?
    Nobel gases
  153. Atoms with different types of nuclear configurations are?
    nuclides
  154. Who discovered xrays? When?
    • Wilhelm Conrad Roentgen
    • late 1800s
  155. Kilogram=
    amount of matter; not its weight
  156. After alpha decay, the atomic # of the parent nuclide will?
    • *loses*
    • Decreases by 2
  157. Mixture?
    combo of 2 or more sub in such a way that are not chemically bound together
  158. After beta decay the number of a daughter nuclide?
    Increases by 1
  159. Write particles & their charges & know which has the greatest mass to the least amount?
    • 1. neutrons: most mass- no charge
    • 2.Proton: more mass teh an electron but less mass then a neutron- positive charge
    • 3.Electron: least amount of mass- negative charge
  160. Examples of electromagnetic energy?
    • infrared
    • visible light
    • ultra violet
    • gamma
    • x-rays
    • micro
    • radio
  161. What is Albert Einsteins theory of relativity?
    • E=mc^2
    • matter & energy are interchangeable
  162. Is velocity a derived or base quantity?
    Derived
  163. Penetrating distances in order from which can go the shortest distance to farthest?
    • alpha
    • beta
    • gamma & x-ray
    • neutron
  164. Any atom which is radioactive?
    radionuclide
  165. Any atom which is radioactive bc it has too few or too many neutrons?
    radioisotope
  166. Newton's 1st Law
    A body will remain @ rest or continue moving  with constant velocity if unless acted on by an outside force
  167. Atomic number is? Represented by?
    • number of protons
    • the letter Z
  168. What is the period number?
    Number of shells
  169. Group number is?
    number of e's in the outer shell
  170. Work & energy are both measured in the SI units called?
    joules
  171. Max # of electron shells an atom may have?
    7
  172. Process of removing or adding an electron to an atom?
    ionization
  173. Smallest particle of an element, has all the characteristic properties of that element?
    atom
  174. Chemical properties of an atom are primarily controlled by?
    Valence #
  175. Principle force involved with nuclear binding is?
    strong force
  176. Molecule?
    any time 2 or more atoms are chemically bound together
  177. Rate of radioactive decay is greatly influenced by?
    Independent all forces
  178. Newton's 3rd Law
    for every action there is an equal and opposite reaction
  179. Which particle consists of 2 neutrons & 2 protons bound together?
    Alpha particle
  180. How is a compound formed?
    Ionic or covalent interaction
  181. Most likely radionuclides undergoing spontaneous beta decay will possess an infavorably high N/Z ratio with an excess of?
    neutrons
  182. The force that acts on an object is equal to the mass of the object multiplied by the acceleration produced?
    Newtons 2nd Law (law of motion)
  183. Force is measured in the SI unit of?
    newtons
  184. Smallest subdivision of a compound that has the characteristic properties of that compound?
    molecule
  185. Thermal Energy?
    • energy of motion @ molecular level
    • directly related to temperature
  186. Def. of electromagnetic energy?
    waves of elecricity & magnetic energy moving together through space
  187. Bohr Atom
    contains a positively charged nucleus surrounded by negatively charged electrons in fixed orbits
  188. Greeks thought all atoms were composed of?
    • earth
    • water
    • fire
    • air
  189. Thomas Atom
    plum pudding
  190. Created the periodic table?
    mendeleev
  191. Schematic display after employed to represent the structure of the atom was developed by?
    Neils Bohr
  192. SI unit for mass?
    kilogram
  193. X-rays have?
    no mass & no charge
  194. A=
    Z plus N
  195. Who said "entities must not be multiplied beyond what is necessary" what is this known as?
    • William of Ockham
    • Ockham's razor
  196. Standard unit of time?
    second
  197. Variations
    • in power distribution is identified by the:
    • Line
    • Compensator
  198. After
    • passing through the step-up transformer, the electrical current waveform is:
    • AC
  199. For the purpose of inducing thermionic emission, the current supplied to the x-ray
    • tube filament is:_______current; ______ voltage
    • High Current; Low Voltage
  200. In the basic x-ray machine circuit, the last electronic device through which
    • high-voltage electricity must pass before reaching the x-ray tube is always the:
    • rectifier system
  201. The x-ray tube envelope is composed
    • of a heat resistant material called?
    • pyrex glass (could be metal also)
  202. The milliamperage stations are activated, heating up
    • the filament and boiling off electrons inthe x-ray tube each time you:
    • a. turn on the machine
    • b. engage the rotor switch
    • c. engage the exposure switch
    • d. release the exposure switch
    • Engage the rotor switch
  203. What is the voltage waveform for the x-ray tube current passing from cathode to
    • anode during an exposure:
    • DC
  204. In an induction motor, an electrical current is induced in:
    Only the rotor
  205. Which part of the x-ray tube is made of thorium-impregnated tungsten:
    Filament
  206. An x-ray machine with three rectifiers would best be described as:
    Half-rectified
  207. Which area would be defined as the area of heat dispersion on the x-ray tube anode (e.g. where does the electrons hit the anode):
  208. Focal Spot
  209. In comparing three-phase x-ray generators to single-phase generators, the
    • three-phase generators produce:
    • a. higher ripple effect
    • b. higher subject contrast in the remnant
    • x-ray beam
    • c. higher effective mA
    • d. lower effective kV
    • Higher effective mA
  210. When the exposure switch is engaged, which circuit
    • is used to apply current to the filament in the x-ray tube?
    • Filament Circuit
  211. The difference in charge between the cathode and anode during an x-ray exposure is
    • called a(n):
    • Potential difference
  212. The maximum number of pulses of electricity that can be produced by a single-phase
    • x-ray generator is per second:
    • 120
  213. The formula, 0.7 X mA X kVp / 1000 gives us the:
    power rating for a single-phase generator
  214. Tungsten is the principle material used in the:
    Anode disk and Filament
  215. The autotransformer has ____ winding(s).
    One
  216. The step-up transformer increases
    • voltage _____ times
    • 500-1000:1
  217. The difference between the sine wave seen on primary vs. secondary sides of the
    • high voltage transformer is the _____.
    • Amplitude
  218. The material often added to a rotating anode disc to reduce surface defects and
    • improve rotational balance is:
    • Rhenium
  219. The efficiency and life span of the filament wire is improved by the addition of:
    Thorium
  220. What is the portion
    • of the induction motor that operates within the vacuum of
    • the enclosed x-ray tube?
    • Rotor
  221. A single-phase waveform has _____ ripple.
    100%
  222. As an x-ray tube ages, the inside
    • can become coated with tungsten which can cause?
    • Arcing
  223. High capacity tube rotors revolve at a maximum ____ rpm.
    10,000
  224. The filament in an x-ray tube is about _____ length.
    1-2 cm
  225. The effective focal spot size is _____ the actual spot size.
    • (e.g. smaller, larger, the same size).
    • smaller
  226. The heel effect is caused by:
    Anode angle
  227. A line voltage compensator is incorporated into the primary circuit of a modern radiograph unit to?
    maintain a constant KVp level
  228. The type of meter that is used to measure the current passing between the electrodes of an x-ray tube?
    milliammeter-seconds meter
  229. A transformer has 60 primary and 12000 secondary turns of wire. How much voltage will be induced on to the secondary side if a 400-volt primary power supply is impressed on the device?
    80 KVP
  230. The voltage in the secondary circuit of a modern x-ray circuit is normally about ________ than the voltage in the primary circuit?
    1000 times higher
  231. The high-tension portion of a modern x-ray circuit does NOT contain which of the following components?
    the filament selector
  232. The use of oil within the sealed housing of the xray tube is provided to?
    increase the thermal cooling of the tube envelope & provide electrical insulation of the tube
  233. Which of the following changes would be associated with a higher amount of current passing through the filament of the xray tube?
    the selection of a higher mA station
  234. The high tension (step-up) transformer of a modern x-ray circuit is most closely related to?
    the high potential required to accelerate the electrons across the tube
  235. Which components are likely foud in the primary circuit of a mdern x-ray unit?
    • Autotransformer
    • timer switch
  236. The high temperatures that are needed to produce the thermionic emmision in the filament of an x-ray tube require a current of about?
    4-6 amps
  237. the majority of components in a modern x-ray circuit are found in the primary circuit. This is done to?
    reduce the risk from electrical shock
  238. The current passing between the secondary of the high tension transformer and the rectifiers is best described as a type of?
    High voltage (KV) AC
  239. In nearly all modern units the use of the large focal is initiated when the exposure setting above ______ is employed?
    300 mA
  240. Most xray machines used in the United States are designed to operate on a 220 volt or 440 volt?
    60 hertz, alternating current power supply
  241. Which current regulating devices are required in the production of the high-voltage direct current needed in the xray production process?
    • rectifiers
    • high-tension transformers
  242. The control of the amount of filament current in most modern radiographic units are directly related to the?
    milliampere selection
  243. IN nearly all-radiographic units, the high-tension transformer is located in an oil-filled tank that also houses?
    • rectifiers
    • filament transformer
  244. In order to maintain a constant filament current as changes are made in the kilovoltage requires the use of a?
    space charge compensator
  245. The milliamperage that is impressed across the x-ray tube will have a substantial effect on the?
    • filament heat
    • rate of photon production
  246. In the filament branch of the primary circuit, the type of meter employed to measure this current is?
    Ammeter
  247. The purpose of a ballistic-type milliampere-second meter is to measure current flow when?
    rapid exposure time setting and employed
  248. The main component of a line voltage compensator is a device that is capable of storing small amounts of electrical charge called?
    a capacitor/condenser
  249. The selection of voltage to the primary of the high-tension transformerin a 3-phase unit is made by?
    3 autotransformer
  250. In order to operate properly x-ray tube requires direct electrical connections to the?
    • filamnent circuit
    • secondary circuit
  251. The midpoint of the high-tension transformer in a modern xray circuit is grounded. This serves to reduce?
    amount of cable insulation
  252. The selection of voltage to the high-tension transformer is most commonly made by adjusting the settings on the?
    autotransformer
  253. The pre-reading kv meter is incorporated into the xray control panel to measure the potential difference on the?
    secondary side of the high tension transformer
  254. Which component is NOT generally located in the high voltage portion of a modern xray circuit?
    filament transformer
  255. Circuit overloads occuring in the sensitive components of an electrical circuit can be prevented by the use of which of the following devices?
    • fuses
    • circuit breaker
  256. What is usually found on the operating console of a x-ray machine?
    • kv control
    • mA control switch
    • timer control switch
  257. What can be used for the storage of electrical charge?
    battery
  258. The most common device used to create the high potential difference (kilovoltage) across the xray tube is the high tension?
    transformer
  259. The reduction of voltage and development of high amperage by a step-down transformer occurs in the?
    filament portion of the circuit
  260. In the radiographic unit, the milliammeter will register only during the activation of the?
    second (exposure) stage of the exposure switch
  261. A transformer has 2000 primary and 200 secondary turns of wire. How much voltage will be induced onto the secondary side if a 200 volt primary power supply is impressed on the device?
    20 volts
  262. Primary circuit=
    110, 220 or 440 volts
  263. Filament circuit=
    10-12 volts
  264. secondary circuit=
    25000-150000volts
  265. What is contained in a typical high-voltage generator?
    diode rectifiers
  266. A change in the voltage waveform from the primary side to the secondary side of the high-voltage transformer produces a change in?
    Amplitude
  267. In half-wave rectification, each inverse half-cycle in the primary circuit corresponds to how many voltage pulses across the xray tube?
    none
  268. Which is higher for a single-phase high-voltage generator than for a 3phase high-voltage generator?
    voltage ripple
  269. What is a disadvantage of three-phase power compared with single-phase power?
    higher capital cost
  270. Disadvantage of a self-rectified circuit is?
    its limited exposure time
  271. An exposure of 1/10s?
    produces twice as much radiation if full-wave rectified than if half-wave-rectified
  272. Full-wave rectification?
    requires at least four rectifiers
  273. A rectifier?
    can be a semiconductor
  274. concerning the transformers used in the xray circuit?
    the high-voltage transformer is a step-up device
  275. What is an advantage of three-phase power over single-phase power?
    increased xray intensity per mAs
  276. Oil is used in the high-voltage section of an xray imaging system for which of the following functions?
    electrical insulation
  277. Which power supply should provide the highest quality xray beam?
    high-frequency
  278. Full-wave rectified power has what voltage ripple?
    100%
  279. Half-wave rectified power has what voltage ripple?
    100%
  280. High-frequency power has what voltage ripple?
    1%
  281. Three-phase, six-pulse power has what voltage ripple?
    13%
  282. Three-phase, 12 pulse power has what voltage ripple?
    4%
  283. 2 main electrical requirements of an Xray tube?
    • a filamnet current of a few amps
    • a voltage between the filament and the anode of 1000 volts
  284. An xray generator converts ________ energy into ________ energy?
    electrical; radiant
  285. The part of the xray generator that supplies the high voltage necessary between the cathode and the anode is called the __________ circuit?
    tube
  286. The part of the xray generator that supplies current and voltage to the cathode of the xray tube is called the ______ circuit?
    filament
  287. The main power line in a hospital is usually a ______ volt, _______ hertz A.C. source?
    220; 60
  288. Each of the hot wires in the main power lines varies up to _____ volts positive or negative, with respect to the neutral wire?
    110
  289. The turns ratio of an __________ can be varied by selecting the number of turns between connections on a single coil?
    autotransformer
  290. The voltage on the secondary side of the autotransformer shown below will be ________ when the selector is at position 2 than when it is at position5?
    higher
  291. To raise the voltage higher than the autotransformer is capable of raising it, a ________ transformer is included in the tube circuit?
    step-up
  292. The autotransformer is connected to the ________ side of the step-up transformer?
    primary
  293. If a step-up transformer has a turns ratio of 500 to 1 and a voltage of 220 volts exists on the primary side, then a voltage of ________ volts will exist on the secondary side?
    110,000
  294. An xray tube operates most efficiently with ______ but the autotransformer and step-up transformer requir ______?
    D.C. ; A.C.
  295. The circuit component that changes A.C. to D.C. is called a?
    rectifier
  296. A ______ is a device that allows current to flow in one direction only?
    diode
  297. The two types of diodes are?
    • solid state
    • tube-type
  298. Electrons will flow through the diode shown below from _______ to ______?
    left to right
  299. In a modern xray circuit, the rectification of high voltage alternating current into pulsating direct current occurs between the secondary of the high tension transformer and the?
    xray tube
  300. IN a 3 phase, 6 pulse rectified unit how many voltage peaks are produced for each cycle of incoming line voltage?
    6 peaks
  301. What is the advantage of a 3 phase power supply in a modern radiographic unit?
    reduced scatter production
  302. the principle material that is used in the formulation of a solid state diode is?
    silicon
  303. In a 3 phase radiographic unit, if one of the rectifiers is damaged prior to a radiographic exposure, which of the following is likely to occur?
    a reduced amount of optical density due to a decreased radiation output
  304. A radiographic exposure is taken on a 3-phase , 6 pulse unit, In order to maintain the same optical density using a full wave unit would require?
    a doubling of mAs value
  305. The process by which alternating current is converted into pusating direct current is termed?
    rectification
  306. IN a 3-phase, 12 pulse unit, rectificaion is accomplished by employing?
    12 solid state diodes
  307. A full-rectified waveform is represented by number?
    3
  308. 3 phase alternating current waveform, is represented by number?
    4
  309. The curve represented by #5 is best described as a/an?
    steady direct current curve
  310. What #s represent direct current waveforms?
    2,3, & 5 only
  311. The main advantage of the 3-phase, over single-phase (full wave) current, is that in 3-phase current, the voltage?
    never drops to a zero voltage
  312. The type of unit most likely to possess the smallest voltage ripple is a?
    3-phase, 6-pulse unit
  313. The most common type of rectifier for use in 3-phase radiographic equipment is the ?
    solid state diode
  314. Rectification is used to suppress the inverse voltage associated with alternating current before it reaches the xray tube. This helps to?
    prevent the flow of electrons towards the filament
  315. An exposure is made on a full-wave rectified unit. In order to maintain the same optical density for an exposure made with a 3-phase, 6-pulse radiographic unit, the mAs value employed should be decreased about?
    50-55%
  316. With an alternating current source the electron flow will alternate ?
    120 times a second
  317. A 3-phase, 6-pulse unit has an effective kv of about ______ is considered normal?
    100%
  318. A satisfactory radiograph is produced using a 3-phase, 6 pulse unit. If the same technical factors are used on a single-phase unit, the radiograph would show a?
    lower optical density
  319. During the operation of an xray tube being supplied by full-wave rectified current during 50 millisecond exposure, the tube electrodes will change (reverse) polarity?
    no change in polarity occurs
  320. The most common method for obtaining a fully rectified tube current involves the use of?
    four diodes
  321. Compared to single-phase xray unit, a 3-phase unit using the same technical factors will create?
    • more xray photons
    • more anode heat units
    • higher energy photons
  322. The use of 3-phase, radiographic units, has the advantage of ________ when compared to single-phase units?
    higher milliamperage settings
  323. What is the power rating for a unit energized at 800 mA, 100 millisecond and 100 kVp?
    80 kilowatts
  324. 3-phase current consists of three-phase voltage waveforms separated by?
    120 degrees
  325. Solid-state rectifiers as compared to thermionic diode have/are?
    • more durable
    • more efficient
    • a longer life
  326. In modern xray equipment, the device most often used for current rectification is a/an?
    solid state diode
  327. Which of the following types of single-phase radiographic units will permit the greatest instantaneous loading capacity?
    full wave rectified current
  328. The small variation of the voltage waveform of 3- phase rectified current is termed the?
    voltage ripple
  329. In an xray tube, electrons are produced at the negative electrode or _______ and accelerated toward the positive electrode or _________?
    cathode ; anode
  330. Bc electrons are negatively charged, they are ______ the anode and ________ the cathode?
    attracted ; repelled by
  331. The process in which electrons are boiled off the filament is called?
    Thermionic emmision
  332. The electrons that have been boiled off the filament are attracted to the _______?
    Anode
  333. The small area within which a beam of electrons strikes the anode is called the?
    focal spot
  334. 2 reasons why the element tungsten is the main ingredient of an anode?
    • high atomic #(74); helps to produce more bremsstrahlung
    • high melting point
  335. One purpose of the glass covering that surrounds the xray tube components is to form a vacuum between the anode and cathode. Why is it desirable to minimize the amount of air in an xray tube?
    If air molecules are present, the e` strike them and lose some of their KE.
  336. The xray tube is enclosed in lead to prevent?
    leakage radiation
  337. The size of the focal spot as seen from the pt's point of view or as received by an image receptor is called the _______ focal spot?
    effective
  338. Bc the anode is angled somewhat, the actual focal spot _______ than the apparent focal spot?
    larger
  339. 2 purposes for using an angled anode as shown in the above drawing?
    • It allows heat to be spread over a larger area on the anode
    • A small effective focal spot ensures a better quality radiograph
  340. To cover the range of imaging needs from low to high mA values while maintaining as small a focal spot as possible, most general purpose diagnostic x-ray tubes have ____(____) filaments?
    two (oval)
  341. 2 problems that occur if you attempted to force a tube current of 350 mA through a small filament?
    • filament might overheat
    • focal spot might be so small that excessive amounts of heat could build up in a small area of the anode
  342. Some generally accepted values of kVp, mA,and time for standard radiological studies are listed on a _____ chart?
    technique
  343. A _____ chart shows how much heat is deposited in the anode when various kVp, mA, and time combinations are used?
    tube

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