"306. When referring to digital imaging what does the term digital mean"

Using numbers to compute images

312. Where in the x-ray circuit is the timer located

Between the autotransformer and the step up transformer

313. Where is the rectification circuit located in an x-ray circuit

Between the step up transformer and the x-ray tube.

318. Which of the following happens when a current and conductor increases

Magnetic field strength increases

319. Which of the following happens when a wire moves through a magnetic field

An electromotive force is induced in the wire

"Which of the following is NOT an advantage of automatic exposure control (AEC): eliminates the need to select mAs

duplicates radiographic densities

322. Which of the following is not an advantage of solid state rectifiers over valve tubes

Melting point is lower in silicon

With digital imaging brightness and contrast are almost always acceptable. What would cause a digital image to display low contrast

Overexposure of the imaging plate by 4x's

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Radiogra Phys Review

Physics of Radiography

Question	Answer
"When an increase in kV causes no addition increase in mA this is known as what"	Saturation current
"304. When electrons strike the anode of a xray tube how much of their energy is converted to xrays"	Less than 1%
305. When electrons strike the target of an xray tube most of their energy is converted to what	Heat
"306. When referring to digital imaging what does the term digital mean"	Using numbers to compute images
307. When the computers in the hospital are connected together you have a ___	LAN
308. When the distance between two charged bodies is cut in half how much will the force between them increase	4 times
309. When voltage increases what happens to amperage	Increases
310. When will a space charge be present in the xray tube	Whenever the rotor is engaged
311. Where are the electrical charges found on a conductor	Outer surface
312. Where in the x-ray circuit is the timer located	Between the autotransformer and the step up transformer
313. Where is the rectification circuit located in an x-ray circuit	Between the step up transformer and the x-ray tube.
314. Which of the following causes electrons to move in a conductor	Voltage
315. Which of the following determines the strength of a magnetic field	The number of flux lines
316. Which of the following devices convert electrical energy to mechanical energy	Motor
317. Which of the following does not refer to a type of transformer loss	Power loss
318. Which of the following happens when a current and conductor increases	Magnetic field strength increases
319. Which of the following happens when a wire moves through a magnetic field	An electromotive force is induced in the wire
320. Which of the following is a device for controlling filament current	Rheostat
"Which of the following is NOT an advantage of automatic exposure control (AEC): eliminates the need to select mAs	duplicates radiographic densities
322. Which of the following is not an advantage of solid state rectifiers over valve tubes	Melting point is lower in silicon
323. Which of the following is not essential to the operation of automatic exposure control (AEC)	Image intensifier
324. Which of the following is placed in a circuit in case of current changes during the exposure	Breaker switch
325. Which of the following is the current indicated by the milliameter	Tube current
326. Which of the following is the most accurate timer	Electronic timer
327. Which of the following materials would make the best transformer core	Soft iron
328. Which of the following meters does not register until an x-ray exposure is made	Milliameter
329. Which of the following rules will determine the direction of force on a current carrying wire	The right hand rule
330. Which of the following rules will determine the direction of the magnetic field around an electrical current	A left hand thumb rule
331. Which of the following types of current supplies the x-ray tube	Pulsating direct current
332. Which of the following would not be located on the primary side of the x-ray circuit	X-ray tube
333. Which part of the xray tube has the filament wires and focusing cup	Cathode
334. Which particle in the nucleus has no charge	Neutron
335. Which type of current is supplied by a battery	Direct
336. Which type of rectification will supply the x-ray tube with the greatest power	Full wave
337. Which will create the least electrical resistance	Copper
338. Who is given credit for describing what an atom looks like	Bohr
Why are three phase generators more efficient at producing x-rays than single phase generators	Voltage never drops to zero.
Why is the xray tube made from lead impregnated glass and encased in a lead housing	Prevent leakage radiation
Why is the xray tube made of Pyrex glass	To better withstand heat
With digital imaging brightness and contrast are almost always acceptable. What would cause a digital image to display low contrast	Overexposure of the imaging plate by 4x's
Xrays are very much the same as what	Gamma rays
What surrounds every electrical current	Magnetic field
285. What technical factor increases the penetrating power of the xray tube	kVp
286. What techniques can be used to reduce patient exposure since cassette-based digital systems require more exposure than film screens	"High kVp
287. What term is used in digital radiography to describe radiographic quality	Brightness
288. What term is used to describe long term storage of digital images and document	Archive
289. What term refers to adding text to a digital image	Annotate
290. What term refers to the number of electrons in the outer shell of an electron	Valence
291. What type of bond holds atoms together by sharing their outer electrons	Covalent
292. What type of current flows between the step up transformer and the rectification circuit	Alternating
293. What type of current is supplied to the radiology department	Alternating
294. What type of motor drives the rotating anode	Induction
295. What type of primary radiation is produced when the xray tube voltage is below 70 kVp	Bremsstahlung
296. What type of radiation is produce when a high speed electron is slowed down or suddenly stopped	Bremsstrahlung
297. What type of transformer core is most efficient	Shell type
298. What type of transformer core is most widely used in radiographic equipment	Shell type
299. What type of transformer has more turns of wire in the secondary side than primary side	Step-up transformer
300. What types of tubes are used in modern xray equipment	Coolidge
301. What will create the most electrical resistance	Long wire small diameter
302. When an electron is accelerated through a potential diff of 1 volt how much work is done	1 electron volt
What is the unit of radiation exposure in air	Roentgen
266. What is the universal standard that allows various digital imaging devices to work together no matter the manufacturer	DICOM
267. What is the voltage supplied to the auto transformer	Line voltage
268. What is true concerning a voltmeter	It must be connected in parallel
269. What is true concerning series circuits	Amperes remains constant throughout
"270. What is true	concerning patient exposure and resolution
271. What is used to focus the electron stream toward the target of the anode	Focusing cup
272. What kind of filtration is manufactured into the xray tube	Inherent
273. What kind of storage is RAM used for	Temporary
274. What law states that energy cannot be created or destroyed only changed	Law of Conservation of Energy
275. What law states the resistance in a circuit is equal to the voltage divided by the current	Ohms law
276. What makes an atom neutral	Same number of protons and electrons
277. What makes up the cathode end of an xray tube	Filaments and focusing cup
"278. What must be applied in order to set a resting by in motion- potential energy	work
279. What occurs when the imaging plate or detector is grossly overexposed	Saturation
280. What produces the least load on an xray tube	"High Kvp
281. What represents high energy xray photon	Short wavelength
282. What subatomic particle is the largest	Neutron
283. What subatomic particles are found in the nucleus of an atom	Protons and neutrons
What is the process that changes a neutral atom into an electrically charged atom	Ionization
242. What is the product of force times distance	Work
243. What is the purpose of the anode in the xray tube	Decelerates electrons
244. What is the purpose of the window in the xray tube	Emission of xrays
245. What is the push or pull of an object called	Force
246. What is the resistance of a body to any change of its present state called	Inertia
247. What is the resistance to flow of electricity and an alternating current called	Impedance
248. What is the rule for erasing the fog caused by background radiation from the imaging plate	Erase the plate if it has been unused for 48 hours
249. What is the simplest type of rectification	Self rectification
250. What is the smallest particle of an element that still has the same characteristic of the element	Atom
251. What is the smallest subdivision of a material that still has the same chemical properties of that material	Molecule
252. What is the smallest subdivision of a substance	Molecule
253. What is the special resolution of a 24 cm x 30 cm (10x12) imaging plate	4 lp/mm
254. What is the splitting of an atomic nucleus called	Fission
255. What is the technical name for a computed radiographic imaging plate	PSP
256. What is the unit for resistance	Ohm
257. What is the unit of capacitance	Farad
258. What is the unit of electrical charge	Coulomb
259. What is the unit of electrical current	Ampere
260. What is the unit of electrical power	Watt
261. What is the unit of force	Newton
262. What is the unit of length in the metric MKS system	Meter
263. What is the unit of mass in the metric system	Kilogram
264. What is the unit of power	Watt
What is the diameter of a typical rotating anode	3 inches
221. What is the disadvantage to using a CR rather than film	Decreased special resolution
222. What is the distance between 2 wave crests of an electromagnetic wave called	Wavelength
223. What is the energy called that attracts electrons to the nucleus of an atom	Binding energy
224. What is the formula for converting Fahrenheit to degrees Centigrade	5/9(F-32)
225. What is the formula for electrical power	P=VI
226. What is the formula for heat units in a 3 phase 6 pulse x-ray unit	mA x kVp x time x 1.35
227. What is the formula for Newtons 2nd Law	F=ma ( Force= (mass)(acceleration) )
228. What is the last name of the man who discovered that a magnetic field surrounds an electrical current	Oersted
229. What is the main advantage of a parallel circuit	Independence of the branches
230. What is the main device for high voltage control of x-ray equipment	Autotransformer
231. What is the major reason for using alternating current	Transformers cannot operate without it.
232. What is the mass per unit volume of a substance called	Density
233. What is the maximum KVP produced by most 3 phase generators	150
234. What is the meaning of the term diode	A tube with 2 electrical terminals
235. What is the most efficient means of transporting electrical energy	High voltage and low amperage
236. What is the name of the closed path over which electric current flows	Circuit
237. What is the negative end of an xray tube	Cathode
238. What is the negative terminal of the xray tube	Cathode
239. What is the prefix for 1 million	Mega
"240. What is the process of ""boiling off"" electrons called"	Thermionic emission
What is equal to one volt	1 joule/coulomb
204. What is inertia	It is the tendency of a body to remain at rest or stay in motion unless acted upon by an external force
205. What is it called when a current is induced in a secondary coil by simply changing the current in the primary coil	Mutual induction
206. What is it called when a solenoid has an iron core in its center	Electromagnet
207. What is it called when the primary photon changes direction but not energy	Coherent
208. What is most likely to damage the xray tube	Exceeding the tube rating chart
209. What is necessary to connect a computer outside the hospital to the hospitals network	VPN (virtual private network)
210. What is not needed to produce xrays	Focusing cup
211. What is not related to the force applied to an electrical charge	Amperage
212. What is required of a target metal in an xray tube	"Ability to conduct heat
213. What is the area of the xray target called that is struck by the electrons	Actual focal Spot
214. What is the biggest advantage of digital imaging over traditional film	Wide latitude
"215. What is the branch of science that deals with matter	energy
216. What is the definition of energy	The ability to do work
217. What is the definition of power	The rate of which work is done
218. What is the device called that allows current to flow in only one direction	Semiconductor
219. What is the device called that measures electrical current	Ammeter
What does not affect the attenuation of the xray beam	Speed
183. What does one have when all the elements are arranged in a series according to their atomic numbers	Periodic table
184. What does PACS stand for	Picture Archiving Communication Systems
185. What does RAID stand for	Redundant Array of Independent Disks
186. What does RAM stand for	Random Access Memory
187. What does the CR reader use to release the energy stored in the imaging plate	Red laser light
188. What does the prefix kilo stand for	"1
189. What effect will increasing the kVp have on the production of xrays	Their energy will increase
190. What effects does adjusting the filament control have on the production of x-rays	Controls the quantity
191. What electrical device will prevent equipment damage if current gets too high	Circuit breaker
192. What electromagnetic wave has the shortest wavelength	Xrays
193. What formula describes electrical current	Q/T
194. What has the greatest effect of contrast	Compton
195. What interaction does not occur under 125 kvp	Pair production
196. What is a byproduct of photoelectric effect	Photoelectron
197. What is a current carrying coil of wire called	Solenoid
198. What is a device called that stores electrical charges	Capacitor
199. What is a material called that will attract small pieces of iron	Magnet
200. What is a spring shaped coil of wire called	Helix
201. What is a step by step procedure for solving a problem or accomplishing a task	Algorithm
202. What is an xray tube immersed in oil	Insulation
What can cause the histogram to include unnecessary data	Poor positioning and collimation
164. What caused pitting of the xray tube target	Moderate overloading of the xray tube
165. What causes an atom to change to a different atom	Addition/subtraction of a proton
166. What causes most xray tube failures	Excessive heat
167. What characterizes the Compton Effect	Recoil electron
168. What controls image brightness	Window leveling
169. What controls the incoming voltage to the auto transformer	Main breaker switch
170. What could cause histogram analysis error	"Improper collimation
171. What describes an electron	Mass and a negative charge
172. What describes the radiation that makes up the xray beam after is has attenuated the pt	remnant
173. What determines the quantity of electrons that can be stored in a capacitor	"The area of the plates
174. What determines the QUANTITY of electrons that will be accelerated across the xray tube	Heating of the filament
175. What determines the transformer ratio	Turns of wire
176. What determines the wavelength of an xrays	Kilovoltage
177. What device would be used when the milliamperage is set on the control panel	Rheostat
178. What differentiates the Coolidge tube from the Crooke's tube	Hot filament wire
179. What do you call an atom that has a full outer shell	Chemically inert
180. What does CCD stand for	Charge-couples device
181. What does it mean to direct capture a digital image	All the digital data is sent from the modality to the PACS
"To prevent a Moire pattern in your CR image it is best to have the grid lines running ___ to the direction of the laser beam"	Perpendicular
"145. To produce equal density and contrast exposure to the patient with high frequency equipment is __________ compared to single phase"	Equal
"146. Visually dynamic range refers to what"	How many shades of gray are represented
147. What advantages do digital systems have over film screen	Increased dynamic range and more contrast resolution
148. What are atoms called that have the same atomic number but different masses	Isotopes
149. What are charged atoms called	Ions
150. What are materials called that are not attracted to a magnet	Non magnetic
151. What are materials called that are slightly repelled by a magnet	Diamagnetic
152. What are materials called that are strongly attracted to a magnet	Ferromagnetic
153. What are materials called that are weakly attracted to a magnet	Parramagnetic
154. What are protons and neutrons called	Neucleons
155. What are the fundamental metric units of physics	"Meters
156. What are the magnetic lines called that surround a magnet	Flux lines
157. What are the particles called that continuously circle the nucleus of an atom	Electrons
158. What are the swirling currents called that are induced in transformers and produce heat losses	Eddy Currents
159. What are the three methods of electrification	"Friction
160. What are the two kinds of electrical charges	Positive and Negative
161. What are the xray tubes called that have 2 filament wires	Dual focus tubes
162. What can be used to determine safe exposure	Tube rating chart
The latent image can remain stored in the PSP plate for ___ hours before information is lost	8
131. The mass number of an atom is equal to what	Protons+neutrons
132. The max. xray energy will be equal to what	KVP
133. The minimum matrix size for an acceptable digital xray is what	1024 x 1024
134. The number of cycles per second that are associated with an alternating current are known as the currents...	Frequency
135. The quality of a digital image depends on what	"Histogram.. look-up table and display monitor"
136. The size of the pixel produced when a cassette-based imaging plate is read depends on what	"The speed of the imaging plate as it passed through the reader & the frequency with which the data is sampled & and the dimension of the laser beam"
137. The small craters in the target of the anode of an xray tube are known as what	Pitting
138. The special resolution is determined by what	Matrix size and the size of FOV
139. The speed of an object in a given direction is referred to as what	Velocity
140. The spinning top test can be used to determine the accuracy of which of the following	Rectification circuit
141. The target of an x-ray tube is made of what	Tungsten
142. The work done on a charged particle is measured in which of the following units	Volts
143. To determine how fast an xray tube will dissipate heat after several exposures what would be used	Anode cooling curve
Specific gravity is the ratio of the density of a substance to the density of what	Water
113. Speed of the wave equals frequency times what	Wavelength
114. Tapping windings of the autotransformer to supply voltage to the step up transformer is the purpose of which of these	KVP selector
115. TFT stands for what	Thin film transistors
116. TFT's are found in which type of digital systems	Cassette-less
117. The 3D volume of tissue that is represented in each pixel is called what	Voxel
118. The ability of a moving body to do work is called	Kinetic energy
"119. The ability to digitally record a small object its accuracy and its clarity defines what"	Spatial resolution
120. The amount of exposure required for CR is similar to what film- screen systems	200 speed
121. The atomic number of an atoms is equal to __	The number of protons
122. The branch of physics pertaining to the origin and nature of xrays is defined by what	Radiologic physics
123. The changing of alternating current to direct current is known as what	Rectification
"124. The electrons are held in a ""cloud"" around the filament wires by the __"	Focusing cup
125. The flow of electrons is known as what	Current
"126. The formula mA x kVp x time is used to determine what"	Heat units
127. The half layer is an expression of what of the xray beam	Quality
128. The histogram us used to automatically rescale the image to the proper brightness. What could cause an error with the histogram analysis	"Exposure field not detected.. unexpected meter in the data set.. and gross over exposure"
129. The incoming line voltage is 220 volts. 55% of the turns on the autotransformer are used. What is the voltage sent to the step up transformer	121 volts
Material that freely allows the flow of electrons is called	Conductor
Materials that are difficult to magnetize and demagnetize are said to have a high...	retentivity
Materials that are easily magnetized and demagnetized are said to have a high...	Permeability
Maximum induction will occur when a conductor cuts a magnetic field at what angle	90 degrees
Most CR readers scan the imaging plate at what frequency	2000 x 2000
100. Most radiographic equipment that is manufactured today uses which type of x-ray generator	High frequency
101. Noise in low exposure areas and saturation in high exposure areas can result when what post processing technique is exclusively applied	Equalization
102. One image per plate is preferred. What must be done to ensure ideal prossessing of the image	"Center part to IR & center tube to IR & 4 collimated borders are recognized"
103. One thousands of an ampere is referred to as what	mA
104. Organized and classified knowledge defines what	Science
"105. Presently cassette-less systems do not have exposure indicators. What can determine if the proper exposure was made"	Measure the dose area product (DAP)
106. Quality of the xray beam refers to what	Energy of xrays
"107. Random background interface that is often referred to as ""snow"" on a television is called"	Noise
108. RIS stand for what	Radiology Information System
109. Self rectification leads to a voltage wave form that is the same as which of the following	Half wave
110. Silicon with an excessive number of electrons is referred to as what type of semiconductor	N type
111. Smoothing can be applied to a digital image to mask what	Noise
If the Nyquist frequency and the grid frequency are approximately the same what can occur	Moire Effect
80. If the peak kilovoltage on a single phase unit is set on 100 kvp what will the RMS value be	70.7 kv
"81. If the voltage is stepped up what happens to the current in the secondary side of the transformer"	Decreases
"82. If used properly will an xray tube last forever"	"No
83. In a direct capture flat panel detector the xray strike the __ layer where electrons are released. The electrons are captured in the ___ layer and stored in a capacitor. The TFT arrays are deposited onto a ____ substrate	"Photoconductor and TFT and glass"
"84. In a modern rotating anode xray tube what coats the tungsten disk"	Tungsten rhenium alloy
"85. In a sixty cycle alternating current how many alternations are there every second"	120
"86. In digital radiography Nyquist is referring to what"	The sampling frequency of the digital data
"87. In digital subtraction which image is usually used for the mask"	The image right before the contrast appears
88. In order for the computer to accurately locate the appropriate anatomy the part must be centered to the cassette and at least __ sides of collimation detected	4
89. In the normal diagnostic range what is the normal wavelength range	.1 to .5 angstroms
"90. In the x-ray circuit diagram the letter 'x' is directly above which of the following circuit components"	Step down transformer
"91. In the x-ray circuit diagram the letter 'x' is directly above which of the following circuit components"	Rectification circuit
92. In what units is filament current measured	Amperage
93. In which direction do magnetic flux lines travel	North pole to south pole
"94. List the layers (top to bottom) in a indirect flat panel detector"	"Fluorescent layer- photodetector layer- and TFT layer"
How efficient is a typical transformer	95%
56. How fast so high speed anodes rotate	"10000 RPM"
57. How many angstroms are in a meter	10 billion
58. How many cm are in a meter	100
59. How many cm are in an inch	2.54
60. How many electrons may occupy the M shell of an atom	18 (2n^2)
61. How many kilovolts is equal to 75000 volts	75kV
62. Howmanymmareinacm	100
63. How many pounds are in a Kg	2.2
"64. How many solid state rectifiers are needed to produce a single phase	full wave rectified current"
65. How much energy is needed to produce pair production	1.02 MeV
66. How will a magnetic field affect the xray beam	No effect
67. How will grid cut off appear on an digital image	Low contrast and noise
68. How will the north pole and south pole of two magnets affect each other	They will attract
"69. How would cutting the distance between two magnets in half effect the attraction force between them"	It would increase four times
70. How would dirt in the light guide of a CR reader appear on a digital image	White lines
"71. If a full wave rectified current has 60 cycles per second how many pulses per second cross the x-ray tube"	120
72. If a neutral atom has an atomic number of 10 how many electrons does it have	10
"73. If a step down transformer has turns ratio of 1:10 what will the output voltage be is the input voltage is 220 volts"	22V
"74. If a step up transformer has a turns ratio of 1:1000 what will the output voltage be if the input voltage is 50 volts"	50 kV
75. If an atoms obtains an additional electron what is its charge	Negative
"76. If only half of the mAs set is registering on the milliameter what could be the problem"	Rectifier malfunction
77. If the current through a resistor is doubled how is the power loss affected	Quadrupled
"78. If the line voltage changes because of demands by other users adjustments must be made in which of the following"	Voltage compensator
Describe a proton	Has mass and a positive charge
38. DEXA is abbreviation for	Dual energy x-ray absorptiometry
39. Dose Are Product ( DAP) is defined by what	The multiplication of the dose and the area exposed
"40. During an exposure	what electrical charge is placed on the anode"
"41. During the thermionic emission a cloud of electrons surround the filament	what is this electron cloud called"
42. Each cell of an image matrix is called what	Pixel
43. Edge enhancement can be applied to a digital image to improve what	The contrast along the edge of the structure
44. Electrons travel in an xray tube from __ to __	Cathode to anode
"45. Every magnet has two poles	what are they called"
"46. Extreme overexposure (at least 4xs) will create black holes in the low density tissue areas of a digital image. The proper term for this effect is"	Saturation
47. Film-screen is least sensitive to ___ levels of radiation	Low
48. From what metal are the filament wires in an xray tube made of	Tungsten
49. How are alternating current values usually expressed	RMS (root mean square) values
50. How are parallel resistors connected	Side by side
51. How are the north poles of two magnets going to affect each other	Repel
52. How can eddy current losses be reduced in a transformer	Lamination
53. How can the radiographer tell if the AEC is calibrated properly when using cassette-based digital systems	The exposure indication is in the optimal range.
"54. How can voltage be induced into a conductor : 1 Move a wire through a magnetic field 2Move a magnetic field across a wire 3 Place a wire in a varying magnetic field"	"(answer is: 1 2 &3) *Michael Feraday discovered that electricity could be produced by any of the above methods."
According to ohms law what would the voltage be if the resistance is 2 ohm and the current is 4 ampere	8 volts
"20. According to the left hand thumb rule which direction would the magnetic field be if the current is towards you"	Clockwise
21. According to the line focus principle the effective focal spot is __ to the actual focal spot	Smaller
"22. After the values of interest have been determined from the histogram what is used to automatically rescale those numbers to produce the proper contrast"	Look-up table
23. An electric current that continually changes direction is known as what type of current	Alternating
24. An electrical charge can be neutralized if it is conducted to what	Ground
25. An excessive amount of electrons at one end of a conductor and a deficiency at the other end is known as	Voltage
26. An indirect (flat panel detector) requires ___ of exposure to produce an optimum quality image	0.5 mR
27. An insufficient amount of mAs with produce a digital image with what	Noise
28. Applying to much edge enhancement to a digital image can result in ___	Halo artifact
29. As electrons accelerate across the xray tube they are referred to as what	Tube current
"30. As kV is applied the electrons are accelerated toward which part of the tube"	Anode
"31. As magnetic domains rearrange in a transformer heat is produced. What is this energy loss called"	Hysteresis losses
32. As the wavelength of an xray increases what happens to the frequency	Decreases
"33. As the xray tube gets older what happens to the temperature of the filament"	Increases
34. Computers operate using a _____ machine language	binary
"35. Contrast resolution is a major advantage of digital imaging what determines high contrast resolution in a digital image"	High exposure and low noise

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