RADIOGRAPHY TESTING LEVEL I
1) Although there may be other reasons for using calcium tungstate screens in industrial radiography, they are most usually used to: \C |A. Improve definition and resolution in radiographic images. |B. Improve contrast in radiographic images. |C. Decreases exposure time. |D. Make films respond to multimillion volt radiation. ^A. Resolution deteriorates with an improvement of the photo electric effect by calcium tungstate. ^B. An increase in the photo electric effect at the film plane by calcium does not improve contrast. ^C. YOU'RE RIGHT! An increase in the photo electric effect increases light action at the film plane and reduces exposure time. ^D. Intensifying screens such as calcium tungstate do not alter the multimillion volt response. 2) An excellent radiograph is obtained under given conditions of exposure with the film located at a distance of 36 inches from the target of the x-ray tube. If the film is now placed only 18 inches from the target, and all exposure conditions except time are held constant, the new exposure time will be: \D |A. unchanged. |B. longer by approximately 80 percent. |C. shorter by approximately 55 percent. |D. only about 25 percent as long as the original exposure time. ^A. The inverse square law states that at 1/2 the distance intensity increases by four. ^B. The inverse square law states that at 1/2 the distance intensity increases by four. ^C. The inverse square law states that at 1/2 the distance intensity increases by four. ^D. CORRECT! The inverse square law states that at 1/2 the distance intensity increases by four; thus, exposure time will be approximately 25% 3) An excellent radiograph is obtained under given exposure conditions with a tube current of 5 milliamperes and an exposure time of 12 minutes. If other conditions are not changed, what exposure time would be required if the x-ray tube current could be raised to 10 milliamperes? \C |A. 24 minutes. |B. 12 minutes. |C. 6 minutes. |D. 3 minutes. ^A. Remember, we have just doubled the possible energy action on the film. ^B. After doubling the number of X-rays you decrease exposure time by 50%. ^C. ALRIGHTY! Doubling the mA from 5 to 10 doubles the amount of X-rays produced and cuts exposure in half. ^D. This is one fourth the original exposure time and mA was only doubled not quadrupled.
4) In film radiography, penetrameters are usually placed: \B |A. between the intensifying screen and the film. |B. on the source side of the test object. |C. on the film side of the test object. |D. between the operator and the radiation source. ^A. Placing the penetrameter after the intensifying screen serves no useful purpose. ^B. YES SIRREEBOB! The penetrameter should be the first thing the X-rays penetrate. ^C. X-rays exiting the back side of the specimen are to weak to provide proper penetrameter resolution. ^D. Placing the penetrameter here does not create an image on the film. 5) When radiographing to the 2-2T quality level, and ASTM penetrameter for 1/2 -inch thick 2024 aluminum alloy has a thickness of: \D |A. 1/2 inch. |B. 2 mils. |C. 5 mils. |D. 10 mils. ^A. A 2-2T means two percent material thickness. ^B. Is .002 two percent of .500? ^C. Is .005 two percent of .500? ^D. AYE! .010 is two percent of .500. 6) The penetrating ability of an x-ray beam is governed by: \A |A. kilovoltage or wavelength. |B. time. |C. milliamperage. |D. source-to-film distance. ^A. RIGHT ON! An increase in the kV produces X-rays with shorter wavelengths and higher penetrating power. ^B. Exposure time has no effect on the penetrating power of Xrays. ^C. Although increasing the mA does increase the number of X-rays produced it does not increase their penetration. ^D. This does effect the penetration of X-rays, but not their initial ability to penetrate a material. 7) Cobalt-60 used in nondestructive testing emits: \C |A. alpha particles. |B. neutrons. |C. gamma rays. |D. x-rays. ^A. An alpha particle is a positively charged Helium nucleus composed of two protons and two neutrons. ^B. Neutrons carry no charge and are ejected during certain radioactive transformations. Can be used for radiography, but not with Cobalt-60. ^C. CORRECTO MUNDO! Gamma rays are emitted by the disintegrating Cobalt-60 atomic nuclei. ^D. X-rays are produced by electron bombardment of a target material. 8) A densitometer is: \B |A. a meter used to measure x-ray intensity.
4) In film radiography, penetrameters are usually placed: \B |A. between the intensifying screen and the film. |B. on the source side of the test object. |C. on the film side of the test object. |D. between the operator and the radiation source. ^A. Placing the penetrameter after the intensifying screen serves no useful purpose. ^B. YES SIRREEBOB! The penetrameter should be the first thing the X-rays penetrate. ^C. X-rays exiting the back side of the specimen are to weak to provide proper penetrameter resolution. ^D. Placing the penetrameter here does not create an image on the film. 5) When radiographing to the 2-2T quality level, and ASTM penetrameter for 1/2 -inch thick 2024 aluminum alloy has a thickness of: \D |A. 1/2 inch. |B. 2 mils. |C. 5 mils. |D. 10 mils. ^A. A 2-2T means two percent material thickness. ^B. Is .002 two percent of .500? ^C. Is .005 two percent of .500? ^D. AYE! .010 is two percent of .500. 6) The penetrating ability of an x-ray beam is governed by: \A |A. kilovoltage or wavelength. |B. time. |C. milliamperage. |D. source-to-film distance. ^A. RIGHT ON! An increase in the kV produces X-rays with shorter wavelengths and higher penetrating power. ^B. Exposure time has no effect on the penetrating power of Xrays. ^C. Although increasing the mA does increase the number of X-rays produced it does not increase their penetration. ^D. This does effect the penetration of X-rays, but not their initial ability to penetrate a material. 7) Cobalt-60 used in nondestructive testing emits: \C |A. alpha particles. |B. neutrons. |C. gamma rays. |D. x-rays. ^A. An alpha particle is a positively charged Helium nucleus composed of two protons and two neutrons. ^B. Neutrons carry no charge and are ejected during certain radioactive transformations. Can be used for radiography, but not with Cobalt-60. ^C. CORRECTO MUNDO! Gamma rays are emitted by the disintegrating Cobalt-60 atomic nuclei. ^D. X-rays are produced by electron bombardment of a target material. 8) A densitometer is: \B |A. a meter used to measure x-ray intensity.
|B. |C. |D. ^A. ^B.
an instrument for measuring the density of a material. a meter used to measure the density of a material. a meter used to measure tube current. This is a dosimeter or Geiger counter. YES INDEEDY! A densitometer is the instrument used to measure for proper film density prior to reading the radiograph. ^C. A densitometer measures image density not material density. ^D. This is an amp meter or voltage meter. 9) The two most common causes for excessively high-density radiographs are: \D |A. insufficient washing and overdevelopment. |B. contaminated fixer and insufficient washing. |C. overexposure and contaminated fixer. |D. overexposure and overdevelopment. ^A. Overdevelopment yes washing has nothing to do with it. ^B. Neither fixer nor washing has anything to do with high density. ^C. Contaminated fixer does not result in high-density. ^D. ABSOLUTELY! Both overexposure and overdevelopment can cause in excessively high-density radiographs which results from an excessive amount of silver bromide being converted to black silver. 10) The time required for one-half of the atoms in a particular sample of radioactive material to disintegrate is called: \C |A. the inverse square law. |B. a curie. |C. a half-life. |D. the exposure time. ^A. This is used in source to distance exposure calculations. ^B. This is a measure of emission intensity from a radioisotope. ^C. AFFIRMATIVE! The only logical choice. ^D. Exposure time is a function of film imaging not radioactive decay. 11) What does the term R/hr refer to when speaking of intensity? \B |A. Radiation limits for humans. |B. Roentgens per hour. |C. X-rays per hour. |D. Radiation in hydrogen. ^A. R/hr is R per hour not per human. ^B. ROGER! R/hr equals Roentgens per hour. It is used as a guide for human dosage limits. ^C. This terminology is meaningless. Measuring the number of individual X-rays is next to impossible anyway. ^D. This terminology is even more meaningless than answer C. You need to study more! 12) The ability to detect a small discontinuity or flaw is called: \B |A. radiographic contrast. |B. radiographic sensitivity. |C. radiographic density. |D. radiographic resolution. ^A. This is an indication of the difference between the least dense to the most dense areas of a radiograph.
^B.
VERY GOOD! Radiographic sensitivity is a measure of the ability to detect small discontinuities. ^C. This is the measure of the black silver content of an area of an image on a radiograph. ^D. Close, but resolution deals with the ability to distinguish both large and small interior details. 13) Movement, geometry, and screen contact are three factors that affect radiographic: \B |A. contrast. |B. unsharpness. |C. reticulation. |D. density. ^A. Contrast is not a function of movement or geometry. ^B. PRECISELY! The penumbra shadowing effects are increased by poor geometry, movement blurs normal photographs as well as radiographs, and poor screen contact leads to flogging. ^C. No, try again. ^D. Screen contact maybe, but movement and geometry do not directly affect film density. 14) The difference between the densities of two areas of a radiograph is called: \A |A. radiographic contrast. |B. subject contrast. |C. film contrast. |D. definition. ^A. EXACTLY! It is the difference between the darkest and lightest area of a radiograph. ^B. The contrast of the subject or specimen has nothing to do with the resulting radiograph contrast. ^C. No such terminology; try again. ^D. Definition is an indicator of how well a detail is imaged does not necessarily depend on radiographic density. 15) Upon completing an x-ray exposure and turning the equipment off: \C |A. personnel should wait for a few minutes before entering the exposure area. |B. personnel should wear a lead-lined apron before entering the exposure area. |C. personnel should enter the exposure area without fear of radiation exposure. |D. personnel should take a reading with a survey meter before entering the exposure area. ^A. Why? Once the power is off no more X-rays are being produced and they don't linger about. ^B. Why? Once the power is off no more X-rays are being produced and they don't linger about. ^C. OF COURSE! When the power to an X-ray tube is shut off it immediately ceases to produce X-rays and their is no further danger. ^D. Why? Once the power is off no more X-rays are being produced and they don't linger about. 16) The most widely used unit of measurement for measuring the rate at which the output of a gamma-ray source decays is the: \A |A. curie. |B. roentgen.
|C. |D. ^A.
^B. ^C. ^D. 17) \A |A.
half-life. MeV. MAIS OUI! As the french would say. Named for Madame Curie the discoverer of Radium one Curie equals 3.7 x 1010 atomic disintegrations per second. A roentgen is a measurement of output for both X-ray and gamma ray sources. Half-life is a function of the length of output time not intensity. MeV is a measurement of X-ray output. Exposure to x-rays or gamma rays:
may have a cumulative effect which must be considered when monitoring for maximum permissible dose. |B. will be beneficial since they build up an immunity to radiation poisoning. |C. will have no effect on human beings. |D. will have only a short-term effect on human tissues. ^A. YOU'RE RIGHT! X-rays or gamma rays themselves don't build-up or stay in the body, but their "effects" on the body build over a period of repeat exposures. ^B. No way! Humans cannot become immune to radiation only tan as in the case with sunlight. ^C. Its effects range from mild to deadly. ^D. Can have long term effects on human tissues. Sufficient radiation exposure can produce cancer or tumors which may not appear for many years. 18) Which dose would be dangerous, if not fatal, if applied to the entire body in a short period of time? \C |A. 1.5 to 15 R |B. 25 to 70 R |C. 200 to 800 R |D. All of the above doses would most likely be fatal. ^A. Not enough to be dangerous. ^B. Could be harmful, but not life threatening. ^C. CORRECT! The exact fatal dosage depends on age and body size. ^D. No there is only one correct answer. 19) When doing gamma-ray radiography with high-intensity emitters, the sources are best handled: \B |A. directly by personnel equipped with special protective clothing. |B. by remote handling equipment. |C. directly by personnel with special protective clothing except when radiographs are being made. |D. by the same methods used for low-intensity emitters. ^A. Never directly handle a high emission source. ^B. ALRIGHTY! Never directly touch or handle high emission sources there is no safe practical protective clothing one can use when handling these sources. ^C. Never directly handle a high emission source. ^D. Low intensity emitters can be handled directly when wear the proper protective clothing, but this protection is not enough to handle high-intensity emitters. 20) If a film is placed in a developer solution and allowed to
develop without any agitation: \D |A. the radiograph will not show proper contrast. |B. it will be impossible to fix the radiograph permanently. |C. there will be a general "fogging" condition over the entire radiograph. |D. there will be a tendency for each area of the film to affect the development of the areas immediately below it. ^A. Maybe not necessarily the case especially in radiographs with little overall contrast. ^B. It is still possible to fix the radiograph permanently in this situation. ^C. Fogging is usually caused by scattered radiation not agitation. ^D. YES! Without agitation the developer will be depleted in areas of high film density weakening the development of imaging lying below it in the vertically oriented film rack. 21) The selection of the proper type of film to be used for the x-ray examination of a particular part depends on: \D |A. the thickness of the part. |B. the material of the specimen. |C. the voltage range of the available x-ray machine. |D. all three of the above factors. ^A. Yes, but what else. ^B. Yes, but what else. ^C. Yes, but what else. ^D. CORRECT! The thickness, material, and voltage intensity are all factors to be judged when selecting the proper film. 22) When radiographing a part which contains a large crack, the crack will appear on the radiograph as: \A |A. a dark, intermittent or continuous line. |B. a light, irregular line. |C. either a dark or light line. |D. a fogged area on the radiograph. ^A. RIGHT ON! A crack will appear as a dark linear image because it allows X-rays to pass easily; thus, creating a more intense photo reaction at the film. ^B. This shows only a slight change in material density. ^C. Not as a light line. ^D. Fogging is primarily due to scattered radiation reaching the film not from imaging cracks. 23) A cobalt-60 source has a half-life of: \C |A. 1.2 years. |B. 6 months. |C. 5.3 years. |D. 75 days. ^A. Much longer. ^B. Longer. ^C. CORRECT! ^D. Much, much longer. 24) X-ray tube current is controlled by: \A |A. the current passing through the filament. |B. the distance from the cathode to the anode.
|C. |D. ^A.
the type of material used in the target. the voltage and waveform applied to the x-ray tube. O.K.! The voltage applied across the tube controls the type of X-rays produced. ^B. The distance between the cathode and anode has nothing to do with it, but it is controlled by an element of the cathode. ^C. The type of material at the anode target has no bearing on current. ^D. The voltage and waveform controls the velocity and wavelength of the X-rays produced. 25) The voltage and waveform applied to the x-ray tube be a high-voltage transformer primarily determines the: \C |A. quantity of radiation. |B. duration of exposure. |C. penetrating ability. |D. x-ray beam divergence. ^A. Quantity of radiation is not a function of voltage and waveform. ^B. This is not their primary function. ^C. ROGER! Increasing the voltage produces X-rays of shorter wavelength and high penetrating ability. ^D. The direction or spread of the beam is not a function of voltage or waveform. 26) Lead foil in direct contact with x-ray film: \C |A. intensifies the scatter radiation more than the primary radiation. |B. decreases the contrast of the radiographic image. |C. intensifies the primary radiation more than the scatter radiation. |D. should not be used when gamma rays are emitted by the source of radiation. ^A. Visa-versa. ^B. It increases contrast. ^C. VERY GOOD! Primary radiation (hard X-rays) are only slightly attenuated by lead foil whereas secondary (soft X-rays) or scattered radiation is absorbed almost completely by the foil. ^D. Lead foil is used for both X- and gamma radiography. 27) Fluorescent intensifying screens are usually mounted in pairs in rigid holders called: \B |A. film racks. |B. cassettes. |C. emulsifiers. |D. diaphragms. ^A. These are used to hold film during developing. ^B. PRECISELY! Cassettes hold fluorescent intensifying screens in direct contact with the film in a cassette. ^C. These are wetting agent used in developing. ^D. Intensifying screens are rigid and do not vibrate as with the case of diaphragms. 28) Radiographic sensitivity, in the context of the minimum detectable flaw size, depends on:
\D |A. |B. |C. |D. ^A. ^B. ^C. ^D.
graininess of the film. the unsharpness of the flaw image in the film. the contrast of the flaw image on the film. all three of the above. What about contrast? What about unsharpness? What about film graininess? EXACTLY! Film graininess, unsharpness of the image, and contrast all determine the minimum detectable flaw size.
29) In order to decrease geometric unsharpness: \A |A. radiation should proceed from as small a focal spot as other considerations will allow. |B. radiation should proceed from as large a focal spot as other considerations will allow. |C. the film should be as far as possible from the object being radiographed. |D. the distance from the anode to the material examined should be as small as is practical. ^A. CORRECT! All radiation emitted from a point source for radiography should be as small as possible. ^B. A large focal spot or point source increases scattering and will produce foggy radiographs. ^C. This increases the prenumbral shadow and thus decreases image sharpness. ^D. This is true since the target at the anode is the point source, but this alone will not decrease geometric unsharpness and to close a spacing will increase foggy due to scattering. 30) As the kilovoltage applied to the x-ray tube is raised: \B |A. X-rays of longer wavelength and more penetrating power are produced. |B. X-rays of shorter wavelength and more penetrating power are produced. |C. X-rays of shorter wavelength and less penetrating power are produced. |D. X-rays of longer wavelength and less penetrating power are produced. ^A. Longer wavelengths have less penetrating power. ^B. YOU'RE RIGHT! Increasing the voltage increases the speed of the bombarding electrons on the target to produce shorter wavelength X-rays with higher penetrative power. ^C. Shorter wavelengths have greater penetrating power. ^D. Just the opposite. 31) In order to increase the intensity of X-radiation: \A |A. the tube current should be increased. |B. the tube current should be decreased. |C. the test specimen should be moved further from the film. |D. a lower kilovoltage should be applied to the tube. ^A. CORRECT! The tube current controls the amount of electrons released at the filament that will bombard the target; thus, increasing the number or intensity of X-rays. ^B. This reduces the number of X-rays produced.
^C.
This does not increase X-ray intensity and will result in an increase in the prenumbral shadow on unsharpness. ^D. This does not effect intensity only lowers the penetrating power of the X-rays produced. 32) Primary radiation which strikes a film holder or cassette through a thin-portion of the specimen will cause scattering into the shadows of the adjacent thicker portions producing an effect called: \C |A. radiation imaging. |B. spotting. |C. undercut. |D. unsharpness. ^A. This is radiography in general. ^B. Spotting is usually a result of improper developing. ^C. ALRIGHTY! It undercuts or exposes adjacent film portions and results in a deterioration of image quality. ^D. This is a result, but not the exact name of the effect in question. 33) Scattered radiation caused by any material, such as a wall of floor, on the film side of the specimen is referred to as: \D |A. primary scattering. |B. undercut. |C. reflected scattering. |D. backscattered radiation. ^A. Primary scattering is caused by the specimen itself. ^B. This occurs at the film and is caused by slightly attenuated radiation striking the film cassette or holder. ^C. It can be reflected, but this is not what it is called. ^D. YES INDEEDY! Backscattered radiation is the scattering of radiation after it exits the back of the specimen and bounces off surrounding objects. 34) Which of the following materials is suitable for use in vessels or pails used to mix processing solutions? \A |A. Stainless steel. |B. Aluminum. |C. Galvanized iron. |D. Tin. ^A. YES! Stainless steel will not react with processing solutions. Also most plastics are suitable container materials. ^B. Processing solutions will react with aluminum. ^C. Processing solutions will react with the zinc coating on galvanized containers. ^D. Tin can react with some processing solution and pure tin containers are expensive. 35) Any of the body tissues may be injured by excessive exposure to X or gamma rays but particularly sensitive are: \D |A. blood. |B. lens of the eye. |C. internal organs. |D. all of the above. ^A. How about internal organs? ^B. How about blood? ^C. How about the lens of the eye?
^D.
AFFIRMATIVE! Excessive exposure to X- or gamma radiation is dangerous for any part of the human body. 36) A general rule used to define the amount of radiation exposure that is excessive is: \D |A. Although small amounts of radiation (0.4 R per week or less) are beneficial since they build up an immunity to these rays, anything above 0.4 R per week is excessive. |B. Any dose over 5 R per week is excessive. |C. Any dose which causes a mid-range reading on a Geiger counter is excessive. |D. Any unnecessary exposure to radiation is excessive. ^A. Humans do not develop an immunity to X or gamma radiation. ^B. True, but not a general rule this excessive. ^C. This can vary greatly depending on the sensitivity range of the instrument from mild to deadly. ^D. EXACTLY! Any unnecessary exposure to radiation is not only excessive, but foolish as well. 37) X-ray exposure may be due to: \C |A. the direct beam from the x-ray tube target. |B. scatter radiation arising from objects in the direct beam. |C. both A and B above. |D. both A and B above plus residual radiation that exists for the first few minutes after the x-ray machine has been returned to the "off" position. ^A. Yes, but what else? ^B. Yes, but what else? ^C. OF COURSE! X-rays cease the instant the voltage is cut off, there is not "residue". ^D. There is no residual radiation once the voltage is cut off. 38) A general rule often employed for determining the kilovoltage to be used when X-raying a part is: \B |A. the kilovoltage should be as high as other factors will permit. |B. the kilovoltage should be as low as other factors will permit. |C. the kilovoltage is always a fixed value and cannot be changed. |D. the kilovoltage is not an important variable and can be changed over a wide range without affecting the radiograph. ^A. This is a waste of power, likely to produce a poorer quality radiograph, and creates a greater radiation exposure hazard. ^B. CORRECT! Why waste power to produce a lower quality radiograph at a risk to your and others health? ^C. The kilovoltage (kV) is highly adjustable in industrial X-ray machines to meet a variety of testing requirements. ^D. The kilovoltage (kV) controls the penetrating power of the X-rays produced! This allows the machine to be adjusted to meet various situations. 39) If a piece of lead 1/2 inch thick is placed in the path of a beam of radiation emanating from cobalt-60, it will reduce the dose rate at a given location by: \C |A. one-third. |B. one-quarter.
|C. one-half. |D. three-quarters. ^A. More. ^B. Double it. ^C. YES! ^D. Less. 40) Excessive exposure of film to light prior to development of the film will most likely result in: \A |A. a foggy film. |B. poor definition. |C. streaks. |D. yellow stain. ^A. YOU'RE RIGHT! The "fog" is due to a partial exposure of the film to excess light. ^B. An indirect result. ^C. Maybe. ^D. This is a development chemical problem. 41) White crescent-shaped marks on an exposed x-ray film are most likely caused by: \B |A. crimping film after exposure. |B. crimping film before exposure. |C. sudden extreme temperature change while processing. |D. warm or exhausted fixer. ^A. Not good for the film, but does not result in white crescent-shaped marks. ^B. ALRIGHTY! ^C. Although detrimental, this does not result in white crescent-shaped marks. ^D. This causes a different effect on the film not white crescent-shaped marks. 42) Reticulation resulting in a puckered or netlike film surface is probably caused by: \B |A. crimping film after exposure. |B. sudden extreme temperature change while processing. |C. water or developer on unprocessed film. |D. excessive object-to-film distance. ^A. Not healthy for the film, but will not result in a puckered or netlike film surface. ^B. RIGHT ON! Sudden temperature changes result in reticulation of the film. ^C. This will ruin the film and it should not be used, but this is not the cause of reticulation. ^D. This has nothing to do with the physical effect we are referring to here. 43) Frilling or loosening of the emulsion from the base of the film is most likely caused by: \D |A. water or developer on unprocessed film. |B. low temperature of processing solutions. |C. developer solution contamination. |D. warm or exhausted fixer solution. ^A. Although film splashed or sprayed with water or developer before processing not be used this does not cause frilling or loosening of the emulsion. ^B. This usually results in a underdevelopment of the film not
frilling or loosening. This usually results in over development, underdevelopment, or staining of the radiograph. ^D. YES INDEED! Make sure all chemicals are fresh and at the correct temperature before processing. This is just one of many problems which will result. 44) If an exposure time of 60 seconds was necessary using a 4-foot source-to-film distance for a particular exposure, what time would be necessary if a 2-foot source-to-film distance is used and all other variables remain the same? \C |A. 120 seconds. |B. 30 seconds. |C. 15 seconds. |D. 240 seconds. ^A. A lot less, use inverse square law. ^B. Less, use inverse square law. ^C. O.K.! At half the distance exposure time is one fourth according to the inverse square law. ^D. A whole lot less, use inverse square law. 45) One of the general rules concerning the application of geometric principles of shadow formation to radiography is: \C |A. the X-rays should proceed from as large a focal spot as other considerations will allow. |B. the film should be as far as possible from the object being radiographed. |C. the distance between the anode and the material examined should always be as great as possible. |D. all three of the above are correct. ^A. This increases shadow formation. ^B. This increases shadow formation. ^C. TRUE! The optimum distance depends on specimen size, thickness, film speed, source strength, etc. ^D. Answers A and B are incorrect and actually increase shadow formation. 46) As a check on the adequacy of the radiographic technique, it is customary to place a standard test piece on the source side of the specimen. The standard test piece is called a: \C |A. reference plate. |B. lead screen. |C. penetrameter. |D. illuminator. ^A. In reference to what? This is not correct terminology. ^B. This is used to reduce scattering, not as a "standard". ^C. ROGER! The use of particular penetrameters are determined by the code procedure. ^D. This is a term describing the light board used when reading a radiograph by illuminating the radiograph form behind. 47) The duration of an exposure is usually controlled by: \B |A. controlling the milliamperage. |B. a timer. |C. controlling the source-to-film distance. |D. a choke coil in the filament transformer. ^C.
^A. Indirectly. ^B. YES! This is the direct control. ^C. Indirectly. ^D. Has nothing to do with it. 48) A penetrameter is used to indicate: \D |A. the size of discontinuities in a part. |B. the density of the film. |C. the amount of film contrast. |D. the quality of the radiographic technique. ^A. Not its purpose unlike photographs radiographs are life-size and measurements can be made directly on a finished radiograph. ^B. This is a densitometer. ^C. This depends on factors such as source (gamma or X-ray), source strength, film type, etc. Penetrameters are not used to directly measure contrast. ^D. ABSOLUTELY! Different code requirements state which penetrameter size to use in order to assure a minimum quality level is reached in radiographs. 49) A fluorescent intensifying screen will: \A |A. transform x-ray energy into visible or ultraviolet light to which a photographic emulsion is sensitive. |B. result in reticulation. |C. decrease in graininess of the image when using gamma rays. |D. increase the definition in a radiograph. ^A. VERY GOOD! Hard penetrating short wavelength X-rays convert only on percent of their total energy to image producing light and the use of intensifying screens is sometimes necessary to produce an acceptable image. ^B. This is a processing temperature problem. ^C. They will increase the graininess. ^D. They will increase the graininess and lower definition. 50) The three main steps in processing a radiograph are: \B |A. developing, frilling, and fixation. |B. developing, fixation, and washing. |C. exposure, developing, and fixation. |D. developing, reticulating, and fixation. ^A. No frilling. ^B. PRECISELY! ^C. Exposure is not a part of processing. ^D. No reticulation. 51) Lead foil screens are used in radiography: \C |A. to improve the quality of the radiograph by preferentially reducing the effect of scatter radiation. |B. to reduce the exposure time. |C. both A and B are reasons for using lead foil screens. |D. neither A nor B are reasons for using lead foil screens. ^A. Yes, but what else? ^B. Yes, but what else? ^C. EXACTLY! Lead screens can be used as intensifiers or to reduce the effects of scattered radiation. ^D. At least one answer is correct. 52) Kilovoltage, exposure time, and source-to-film distance are three
of the most important x-ray exposure factors that can be controlled. A fourth such exposure factor is: \D |A. focal point size. |B. temperature. |C. filament-to-focal spot distance. |D. milliamperage. ^A. Effects image quality, but not exposure time. ^B. Effects processing, but not exposure time. ^C. Does not effect exposure time. ^D. CORRECT! Milliamperage controls the number of X-rays produced and therefore controls the exposure time. 53) When the minute silver grains on which the x-ray film image is formed group together in relatively large masses, they produce a visual impression called: \B |A. air bells. |B. graininess. |C. reticulation. |D. frilling. ^A. No, air bells are caused by bubbles of air trapped on the film during processing. ^B. AFFIRMATIVE! Logical choice. Minute silver grains when grouped together increase the graininess of the radiograph. ^C. This is caused by a sudden temperature change in processing resulting in a puckered or netlike film. ^D. Frilling is caused by warm or exhausted fixer. 54) To prevent excessive backscatter from reaching a radiograph film, one should: \A |A. back the cassette with a sheet of lead, the thickness needed depending on the radiation quality. |B. place a mask between the specimen and the front surface of the film. |C. back the exposure holder with a thick sheet of lead (at least 1/2 inch). |D. place a filter in the x-ray or gamma ray beam near the source or x-ray tube. ^A. TRUE! ^B. A mask at the front will not reduce "back" scatter. ^C. 1/2" is too thick! ^D. This will not necessarily reduce backscatter. 55) Static marks, which are black tree-like or circular marks on a radiograph, are often caused by: \D |A. film being bent when inserted in a cassette or holder. |B. foreign material or dirt imbedded in screens. |C. scratches on leak foil screens. |D. improper film handling techniques. ^A. This results in white crescent-shaped marks on the film. ^B. These can appear as specks on the radiograph and can scratch the emulsion leaving white scratch marks. ^C. This usually will not effect the radiograph unless the screen is punctured or torn. ^D. YES SIRREEBOB! Static electricity produced by improper film handling techniques exposed the emulsion producing black tree-like flaws on the resulting image.
56) The purpose of agitating an x-ray film during development is to: \B |A. protect the film from excessive pressure. |B. renew the developer at the surface of the film. |C. disperse unexposed silver grains on the film surface. |D. prevent reticulation. ^A. There should be no pressure on the film at all to reduce. ^B. RIGHTO! Developer is constantly being depleted at the film's surface during processing and agitation is necessary to insure uniform results. ^C. This is on of the purposes of the fixer. ^D. Reticulation is caused by sudden temperature changes. 57) When manually processing films, the purpose for sharply tapping hangers tow or three times after the films have been lowered into the developer is to: \C |A. disperse unexposed silver grains on the film surface. |B. prevent frilling. |C. dislodge any air bubbles clinging to emulsion. |D. all of the above. ^A. This is the purpose of fixation. ^B. To prevent frilling you must maintain the fixer strength and control its temperature. ^C. AYE MATE! Air bubbles will appear as bell shapes on the resulting radiographic image. ^D. Only one is correct. 58) The activity of the developer solution is maintained stable by: \D |A. constant agitation. |B. maintaining processing solutions within the recommended temperature range. |C. avoiding contamination from the wash bath. |D. addition of replenisher. ^A. Yes, but not for the long-term. ^B. This controls only the short-term activity. ^C. Dilution by the bath water will only slightly reduce the short-term developer activity. ^D. YES INDEEDY! Periodic replenishment of the developer is needed to replace the depleted chemical due to processing film. 59) The purpose of fixation is: \D |A. to remove all the undeveloped silver salts of the emulsion. |B. to leave the developed silver as a permanent image. |C. to harden the gelatin. |D. all of the above. ^A. Yes, but what about hardening? ^B. Yes, but what about removing the undeveloped silver salts? ^C. Yes, but what about leaving a permanent image? ^D. ABSOLUTELY! The purpose of fixation is to accomplish all three. 60) For best results when manually processing film, solutions should be maintained within a temperature range of: \A |A. 65 and 75 degrees F. |B. 65 and 75 degrees C. |C. 75 and 85 degrees F. |D. 75 and 85 degrees C.
^A. YES! This is considered the optimum range for processing X-ray films. ^B. Way to hot this is Centigrade! ^C. Cooler. ^D. Extremely hot 100 degrees C is boiling! 61) Water spots on films can be minimized by: \B |A. rapid drying of wet film. |B. immersing wet film for one or two minutes in a wetting agent solution. |C. by using a fresh fixer solution. |D. by cascading water during the rinse cycle. ^A. This will not necessarily reduce water spots can even increase them. ^B. OF COURSE! Wetting agents allow the film to dry evenly and reduce water spotting. ^C. Has nothing to do with water spots. ^D. Water spots are produced in drying and how the fresh water is used to wash the film has no effect. 62) The small area in the x-ray tube from which the radiation emanates is called the: \B |A. diaphragm. |B. focal spot. |C. focusing cup. |D. cathode. ^A. This is used after the X-rays exit the tube. ^B. EXACTLY! ^C. The small area is within the focusing cup, but is not the cup itself. ^D. This is the filament end where the electrons flow. 63) Unwanted inclusions in a part will appear on a radiograph as: \D |A. a dark spot. |B. a light spot. |C. a generalized gray area of varying contrast. |D. either a dark or light spot or area depending on the relative absorption ratio of the part material and the inclusion material. ^A. Maybe. ^B. Maybe. ^C. Not a generalized area very specific area. ^D. TRUE! 64) The radiation quality of a gamma-ray source is: \B |A. determined by the size of the focal spot. |B. determined by the isotope involved. |C. can be varied by the operator. |D. is greater in iridium-192 than in cobalt-60. ^A. There is no focal spot in a gamma ray source. ^B. CORRECT! ^C. The operator has no control over the quality of gamma-rays emitted by a radioisotope. ^D. Cobalt-60 is more penetrating, but their overall quality must be considered almost equal. 65) The most common material used to provide protection against X-rays is: \D |A. high density brick. |B. an alloy of 70 percent steel and 30 percent copper. |C. tungsten. |D. lead.
^A. ^B. ^C.
Not common. Not in this case. Can be used, but is expensive and is commonly used as a target material in X-ray tubes. ^D. VERY GOOD! Lead is very effective, relatively inexpensive, and compact. 66) A curie is the equivalent of: \B |A. 0.001 millicuries. |B. 1,000 millicuries. |C. 1,000 megacuries. |D. 100 megacuries. ^A. This is one thousandth of a curie. ^B. YES! One thousand milli-(one thousandth) curies equal one curie. ^C. This is one billion curies. ^D. This is one hundred million curies. 67) With a given exposure time and kilovoltage, a properly exposed radiograph is obtained with a 6 milliamperes-minutes exposure at the distance of 20 inches. It is desired to increase the sharpness of detail in the image by increasing the source-to-film distance to 40 inches. The correct milliamperage-minutes exposure to obtain the desire radiographic density at the increased distance is: \B |A. 12 milliamperes-minutes. |B. 24 milliamperes-minutes. |C. 3 milliamperes-minutes. |D. 1.7 milliamperes-minutes. ^A. Longer, use the inverse square law. ^B. PRECISELY! Doubling the distance increases the exposure requirement four fold according to the inverse square law. ^C. A lot longer, use the inverse square law. ^D. A whole lot longer, use the inverse square law. 68) Very short wavelength electromagnetic radiation produced when electrons travelling at high speeds collide with matter is called: \A |A. X-radiation. |B. beta radiation. |C. gamma radiation. |D. none of the above. ^A. YOU'RE RIGHT! ^B. Beta radiation is the ejection of a particle and unlike electromagnetic energy has no wavelength only velocity. ^C. This is a short wavelength emitted from certain atomic nuclei and does not involve colliding electrons into matter. ^D. One is correct. 69) The exposure of personnel to X- and gamma radiation can be measured or monitored by means of: \D |A. film badges. |B. dosimeters. |C. radiation exposure survey meters. |D. all of the above. ^A. Yes, but how about exposure survey meters? ^B. Yes, but how about film badges? ^C. Yes, but how about dosimeters? ^D. RIGHT ON! Film badges, dosimeters, and radiation exposure
survey meters are all used to measure or monitor the exposure of personnel to X- and gamma radiation. 70) Assuming that a good radiograph is obtained at a setting of 10 milliamperes in 40 seconds, how much time will be necessary to obtain one equivalent radiograph if the milliamperage is change to 5 milliamperes (all other conditions remain constant)? \C |A. 20 seconds. |B. 10 seconds. |C. 80 seconds. |D. 160 seconds. ^A. More. ^B. Much more. ^C. TRUE! The inverse square does not apply here and cutting the amount of X-rays produced would double the exposure time. ^D. Too much. 71) A graph showing the relation between material thickness, kilovoltage, and exposure is called: \B |A. a bar chart. |B. an exposure chart or technique chart. |C. an characteristic curve. |D. an H & D curve. ^A. No, not a bar chart. ^B. YES! ^C. No, not a characteristic curve this is applied to film density. ^D. No, it's a curve, but not an H & D curve. 72) A graph which expresses the relationship between the logarithm of the exposure applied to a photographic material and the resulting photographic density is called: \C |A. a bar chart. |B. an exposure chart. |C. the characteristic curve. |D. a logarithmic chart. ^A. No, not a bar chart. ^B. No, this deals with material thickness and kilovoltage. ^C. YES! The plot of this function is a characteristic curve depending on film type and the radiation source. ^D. This could be a chart of any logarithmic function, not this relationship though. 73) Short wavelength electromagnetic radiation produced during the disintegration of nuclei of radioactive substances is called: \B |A. X-radiation. |B. gamma radiation. |C. scatter radiation. |D. backscatter radiation. ^A. This is produced by colliding electrons with matter. ^B. CORRECT! Gamma and X- radiation of the same wavelength are identical, but are produced differently. ^C. This can result form both X- and gamma radiation. ^D. This can result form both X- and gamma rays. 74) A photographic image recorded by the passage of X or gamma rays through a specimen onto a film is called a: \B
|A. |B. |C. |D. ^A. ^B. ^C. ^D. 75) is: \D |A. |B. |C. |D. ^A. ^B. ^C. ^D.
Fluoroscopic image. Radiograph. Isotopic reproduction. None of the above. This is a special type of X- or gamma ray photograph, more general. CORRECTO MUNDO! A radiograph is the general term applied to all X- or gamma ray photographs. This is a gamma ray source manufacturing process. There is one correct answer. The normal development time for manually processing X-ray film
12 to 18 minutes in processing solutions at 75 degrees F. 3 to 8 minutes in processing solutions at 60 degrees F. 12 to 18 minutes in processing solution at 68 degrees F. 5 to 8 minutes in processing solutions at 68 degrees F. Too long and a little warm. Too cool. Too long. YES! Just right. Actual time will vary between 5 to 8 minutes depending on other factors. 68 degrees F is considered the optimum developing temperature. 76) In order to achieve uniformity of development over the area of X-ray film during manual processing: \C |A. the film should be placed in a dryer after being developed. |B. the developer should be agitated by means of mechanical stirrers or circulating pumps. |C. the film should be agitated while in the developer. |D. the film should be transformed directly from the developer to the fixer. ^A. This is completely wrong. What about a spot and fixing bath? ^B. Not necessary for agitation to be mechanical in nature. ^C. YOU'RE RIGHT! Agitation is necessary to replenish depleted developer at the film's surface, whether it's mechanical or manual is of no consequence. ^D. What about the stop bath? 77) When referring to a "2T" or "4T" hole in the ASTM penetrameter, the T refers to: \B |A. the part thickness. |B. the penetrameter thickness. |C. the time of exposure. |D. the time for developing. ^A. Wrong thickness. ^B. ALRIGHTY! 2T equals 2% and 4T equals 4% of the material's thickness. ^C. Refers to thickness, not exposure. ^D. Refers to thickness, not developing time. 78) A sheet of lead with an opening cut in the shape of the part to be radiographed may be used to decrease the effect of scattered radiation which undercuts the specimens. Such a device is called: \A |A. a mask. |B. a filter. |C. a backscatter absorber.
|D. ^A.
a lead foil screen. YES INDEEDY! Because it "masks" out everything but the object being radiographed. ^B. Filters do not have holes. ^C. A backscatter absorber is placed behind the film the sheet referred to here is placed in front of the film. ^D. Yes, it is just a lead foil screen, but it has a proper name. 79) Two X-ray machines operating at the same nominal kilovoltage and milliamperage settings: \D |A. will produce the same intensities and qualities of radiation. |B. will produce the same intensities but may produce different qualities of radiation. |C. will produce the same qualities but may produce different intensities of radiation. |D. may give not only different intensities but also different qualities of radiation. ^A. What if their focal spot size differs? ^B. What if the target material differs? ^C. What if the distance between the anode target and cathode differ? ^D. AYE! Many other factors besides kilovoltage and milliamperage determine X-ray intensity and quality. 80) Fluoroscopy differs from radiography in that: \C |A. fluoroscopy used a much lower kilovoltage than radiography. |B. fluoroscopy is much more sensitive than radiography. |C. the X-ray image is observed visually on a fluorescent screen rather than recorded on a film. |D. fluoroscopy permits examination of thicker parts than does radiography. ^A. Not necessarily true. ^B. Not as sensitive as film radiography. ^C. O.K.! This is why it is called fluoroscopy. ^D. Not always the case, radiography permits examination of thicker parts if radiation source strength is equal. 81) An advantage of the pocket dosimeter type of ionization chamber used to monitor radiation received by personnel is: \B |A. it provides a permanent record of accumulated dosage. |B. it provides an immediate indication of dosage. |C. it is the most sensitive detector available. |D. all of the above are advantages. ^A. Does not show permanent accumulated dosage. The dosimeter is used to measure a short-term dose. ^B. ABSOLUTELY! It is not a permanent record. ^C. Not the most sensitive detector available; radiation survey meters are often much more sensitive to detecting radiation. ^D. Only one is correct. 82) The density difference between two selected portions of a radiograph is known as: \B |A. unsharpness. |B. radiographic contrast. |C. specific activity.
|D. ^A.
subject density. Unsharpness can be caused by other factors besides film density. ^B. ROGER! The selected portions should be from the lightest and darkest areas of the radiograph to measure the overall image contrast. ^C. Specific activity refers to the radiation emitted by an isotope and is measured in curies per gram. ^D. The subject refers to the specimen being radiographed not the density of the resulting radiograph. 83) One requirement for keeping fluorescent screens in good condition is that they must: \B |A. be cleaned with a lint-free cloth each time they are used. |B. not be exposed to intense ultraviolet radiation. |C. be mounted in a rigid container at all times. |D. not be exposed to caustic fumes. ^A. Not unless they get dirty. Cleanliness is a good habit, but affects the screen's function very little. ^B. VERY GOOD! UV light depletes the screen of the available material used to intensify the X- or gamma radiograph. ^C. This is not necessary and has no effect on the screens overall performance. ^D. Not wise, and usually has no adverse effect on the screen's overall performance. 84) In making an isotope exposure in an unshielded area, you find the dose rate 6 feet from the source is 1200 mR/hr. What would be the dose rate at 24 feet? \A |A. 75 mR/hr. |B. 100 mR/hr. |C. 200 mR/hr. |D. 300 mR/hr. ^A. PRECISELY! According to the inverse square law increasing the distance by 4 results in 1/16th the exposure. ^B. Less, 1/16th the exposure according to the inverse square law. One fourth squared. ^C. Less. What is one-fourth squared multiplied by 1200? ^D. Less. What is four squared divided into 1200. 85) The intensity of X- or gamma radiation is measured in: \C |A. roentgens. |B. ergs. |C. roentgens per unit of time. |D. H & D units. ^A. Partially correct. ^B. This measurement involves mass and X- and gamma rays are considered to have no mass, just energy. ^C. EXACTLY! Roentgens only refer to the ionization power of the radiation for one cubic-centimeter of air. ^D. No, H & D is the name used for the film characteristic curve. 86) When producing radiographs, if the kilovoltage is increased: \A |A. the subject contrast decreases. |B. the film contrast decreases. |C. the subject contrast increases. |D. the film contrast increases.
^A.
OF COURSE! An increase in kilovoltage produces shorter wavelength X-rays which are less photo-reactive at the film. ^B. The overall contrast of a film is set during manufacture with the slower speed film offering the greatest contrast. ^C. The sorter wavelength X-rays produced are less photo-reactive at the film. ^D. Film contrast is determined mainly by film speed and type. 87) The accidental movement of the specimen or film during exposure or the use of a focus-film distance that is too small will: \C |A. produce a radiograph with poor contrast. |B. make it impossible to detect large discontinuities. |C. result in unsharpness of the radiograph. |D. results in a fogged radiograph. ^A. Contrast may be affected, but movement will blur the image. ^B. Not necessarily true depends on the amount of movement. Movement will have a blurring effect. ^C. YOU BET! Just as in conventional photography movement blurs the image and reduces its sharpness. ^D. This is caused by scattered radiation not movement. 88) A properly exposed radiograph that is developed in a developer solution at a temperature of 58 degrees F for 5 minutes will probably be: \B |A. overdeveloped. |B. underdeveloped. |C. fogged. |D. damaged by frilling. ^A. Remember the optimum temperature is 68 degrees F and developing time of between 5 to 8 minutes. ^B. YEA! 58 degrees F is too cool and five minutes is barely enough developing time for 68 degrees F. The combination of the two results in an underdeveloped radiograph. ^C. This is cause by scattered radiation or excessive exposure to light. ^D. This is caused by too warm or exhausted fixer solution. 89) A good radiograph is obtained using a milliamperage of 15 milliamperes and an exposure time of 1/2 minute. What exposure time will be necessary to produce an equivalent radiograph if the milliamperage is change to 5 milliamperes and all other conditions remain the same? \B |A. 4 1/2 minutes. |B. 1 1/2 minutes. |C. 3 minutes. |D. 1/6 minute. ^A. If the amount of X-rays produced is one-third the exposure time needed to be multiplied by 3. ^B. GOOD! One-third the X-rays means the exposure time must be tripled. ^C. Too long, this is a six fold increase for one-third the amount of X-rays. ^D. This is half the time for one-third the amount of X-rays and would result in a severely underexposed radiograph. 90) Lead screens in contact with the film during exposure: \A |A. increase the photographic action on the film largely by reason of the electron emission and partly by the secondary X-rays generated in the lead. |B. absorb the shorter wavelength scattered radiation more than the long wavelength primary radiation.
|C. |D. ^A. ^B. ^C. ^D. 91) of: \B |A. |B. |C. |D. ^A. ^B.
intensify the photographic effect of the scatter radiation more than that of the primary radiation. none of the above. TRUE! They also reduce fogging due to scattered radiation. Shorter wavelength X-rays are primary X-rays. They increase the photographic effect of the primary radiation. There is one correct answer. The sharpness of the outline in the image of the radiograph is a measure
subject contrast. radiographic definition. radiographic contrast. film contrast. This is a factor dependent on the subject and not the film. SURE! Sharpness is a measure of how well an object is defined against its background. ^C. This is a measure of the film density between two areas of the radiograph. ^D. Contrast is not a measurement of sharpness. 92) An unshielded isotope source gives a dosage rate of 900 mR per hour at 10 feet. What would the unshielded dosage rate be at 30 feet? \C |A. 300 mR/hr. |B. 600 mR/hr. |C. 100 mR/hr. |D. 2700 mR/hr. ^A. Less, use the inverse square law. What is 1/3 squared? ^B. Much less, what is 3 squared divided into 900. ^C. YOU'RE RIGHT! According to the inverse square law the distance is 3 times as much and 3 squared is 9. Therefore, the output is 1/9 of 900. ^D. Way too much, use the inverse square law. How much is 3 squared divided into 900. 93) Which has the shortest wavelengths? \C |A. Visible light. |B. Microwaves. |C. 100 kilovolt peak X-rays |D. Infrared radiation. ^A. Visible light is next to the shortest. ^B. Microwaves are the longest. ^C. CORRECT! These are the shortest. Would 400 kilovolt X-rays be shorter or longer than 100 kilovolt X-rays? ^D. Infrared radiation is next to the longest in this group. 94) Beta particles are: \C |A. neutrons. |B. protons. |C. electrons. |D. positrons ^A. Neutrons can be ejected from an atom's nucleus and be used for radiographic purposes, but they are not Beta particles. ^B. Protons are positively charged particles that lie in the nucleus of every element, but are not Beta particles. ^C. ALRIGHTY! Electrons ejected from an atom's nucleus are
known as Beta particles. This is the particle formed when the incident X-ray photon has sufficient energy to be converted into the mass of and electron/position pair upon colliding with matter. 95) A radioactive source with an activity of one curie has: \D |A. 1,000 disintegrations per second taking place. |B. 1,000,000 disintegrations per second taking place. |C. 1,000,000,000 disintegrations per second taking place. |D. 370,000,000,000 disintegrations per second taking place. ^A. Much much more. ^B. Much more. ^C. More. ^D. YESIRREEBOB! This is a tremendous number of disintegrations, but remember the total number of atoms in a gram of Cobalt-60 equals approximately 1021 atoms. 96) The formula for determining permissible accumulated personnel dose is: \C * THIS IS MOST LIKELY THE OLD FORMULA USED |A. 12 (N-18) |B. 18 (5+N) |C. 5 (N-18) |D. 12 (N+18) ^A. No, but part of your answer is correct. ^B. Not one part of your answer is correct. ^C. CORRECT! ^D. Not one part of your answer is correct. 97) The metal that forms the image on an x-ray film is: \B |A. tin. |B. silver. |C. tungsten. |D. iron. ^A. It's shiny like tin, but it's not tin. ^B. AYE! Silver bromide is a light sensitive compound that reduces to black metallic silver after it is exposed to radiation or light and then developed. ^C. No, this is a common target material used in X-ray tubes. ^D. It's not iron, but its chemical symbol is Ag. 98) Unexposed boxes of x-ray film should be stored: \B |A. flat. |B. on edge or end. |C. in a pile. |D. it doesn't matter. ^A. This could result in pressure damage to the film. ^B. CORRECTO MUNDO! Storing film in a vertical position greatly reduces the chances of pressure damage due to stacking. ^C. Of course not. X-ray film is to expensive and delicate to be treated this way. ^D. Yes it does matter. What way would likely reduce the chance of pressure damage due to the weight of stacking? 99) The lead symbol "B" is attached to the back of the film holder to determine: \B |A. sensitivity. |B. whether excessive backscatter is present. |C. radiographic contrast. ^D.
|D. ^A. ^B.
density. Sensitivity to what? RIGHT ON! The resolution of the lead B on the resulting radiograph indicates the amount of backscatter present during exposure. ^C. What does the "B" stand for? ^D. Would you abbreviate the word density with a "B"? What does the "B" stand for? 100) Penetrameters for _____ are considered Group 1 Materials and need not have an identification notch. \C |A. Inconel. |B. Nickel. |C. Stainless steel. |D. Aluminum bronze. ^A. No, it's the metal made mainly of iron. ^B. No, it's the metal made mainly of iron. ^C. YES INDEEDY! ^D. No, it's the metal made mainly of iron. 101) The purpose of a dated decay curve is to: \C |A. determine the source size at any time. |B. calculate shielding requirements. |C. determine the source strength (activity) at any time. |D. mark the date and length of time for each exposure. ^A. Why would the size measurement be needed at any time? Radioisotopes don't grow smaller. ^B. Shielding requirements must exceed the amount needed for protection at full strength any decay after that is inconsequential. ^C. AFFIRMATIVE! This is the logical choice because size and shielding are set, and atomic decay is not recorded on a film log. ^D. This is a film or exposure log. 102) Why is cobalt-60 used as a radiation source for medium-weight metals of thickness ranges form 1.5 to 9 inches? \C |A. Because of its short half-life. |B. Limited amount of shielding required. |C. Because of its penetrating ability. |D. None of the above. ^A. Its half-life is 5.3 years, hardly short. ^B. Cobalt-60 emits a radiation dose equivalent to a 2 million volt X-ray machine which necessitates maximum shielding. ^C. O.K.! Cobalt-60 emits highly penetrating X-rays of 1.17 and 1.33 MeV. ^D. There is one correct answer. 103) The cause for poor image definition could be: \D |A. too short source-to-film distance. |B. screens and film not in close contact. |C. film graininess. |D. all of the above. ^A. Yes, but what about film graininess? ^B. Yes, but what about too short a source-to-film distance? ^C. Yes, but what about not having your screen and film in close contact?
^D.
ABSOLUTELY! All these factors will contribute to poor image definition. 104) During manual film processing, the purpose of the stop bath is to: \B |A. change the exposed silver salts to black metallic silver. |B. neutralize the developer and stop the developing process. |C. eliminate most water spots and streaks. |D. none of the above. ^A. This is the purpose of the developer. ^B. ROGER! The stop bath contains a weak acid that "stops" the developing action. ^C. No, this is what a wetting agent is used for. ^D There is one correct answer. The stop bath stops something. 105) A thin metallic sheet (brass, copper, aluminum, etc.) placed at the source to reduce effects of softer radiation is known as: \B |A. an intensifying screen. |B. a filter. |C. an electron inducer. |D. a focusing cup. ^A. An intensifying screen is used to increase the radiations photographic effect. ^B. VERY GOOD! By reducing the effect of the soft X-rays the resulting radiograph will be less foggy. ^C. This is not a conventional radiographic term. ^D. This is an element of the X-ray tube. 106) The reason a "shim" is used in radiographic setup is to: \C |A. improve the penetrameter image. |B. reduce diffraction. |C. simulate weld reinforcement. |D. intensity the image. ^A. The penetrameter always receives the same exposure treatment as the rest of the material. ^B. This is the purpose of a screen. ^C. PRECISELY! This is used to check and calibrate the radiographic equipment. ^D. This is the purpose of a intensifying screen. 107) The focal spot size of an x-ray machine must be known in order to determine: \A |A. the geometric unsharpness value. |B. kilovolt peak output. |C. milliamperage settings. |D. exposure time. ^A. EXACTLY! The exact size must be known. This usually is measured in hundredths or thousandths of an inch. ^B. The kilovoltage peak output is not determined by the focal spot. Remember that a smaller focal spot gives a sharper image. ^C. Milliamperage and focal spot do not directly relate. Remember that a small focal spot increases radiographic definition. ^D. Exposure time is determined by factors such as: material thickness, film speed, subject to source distance , source strength, etc. 108) A section with a significant increases in thickness, variation is
required to be shown on a single radiograph within a desired film density range. This may be accomplished by: \A |A. increasing kilovoltage. |B. using a coarser grain film. |C. both A and B are correct. |D. neither A nor B are correct. ^A. OF COURSE! By increasing the kilovoltage shorter more penetrating X-rays are produced, thus enabling a radiograph of equal contrast to be made of the thicker area. ^B. This would probably increase the density range and decrease definition. ^C. Only one is correct. A higher speed film would probably change the density range. ^D. One of them is correct. What would you do to produce shorter higher penetrating X-rays? 109) The density of a radiograph image refers to: \D |A. the thickness of the film. |B. the thickness of the specimen. |C. the weight of the film. |D. the degree of film blackening. ^A. Density refers to compact dark areas of the radiographic image. ^B. Density refers to compact dark areas of the radiographic image. ^C. Density refers to compact dark areas of the radiographic image. ^D. YEA! The blackening is a result of clumps of black metallic silver. 110) A beam of radiation consisting of a single wavelength is known as: \C |A. characteristic radiation. |B. fluoroscopic radiation. |C. monochromatic radiation. |D. microscopic radiation. ^A. Characteristic radiation can be made up of many different specific wavelengths. ^B. There ain't no such animal. Which answer begins with "one" for one wavelength? ^C. GOOD! Monochromatic literally mans one (mono) color (chromatic). Generally light and thus radiation are thought of as having a color (wavelength). ^D. Micro what? Look at the other answers which one begins with a prefix meaning "one" for one wavelength? 111) The image of the required penetrameter and hole on the radiograph indicates that the radiograph has the required: \C |A. contrast. |B. definition. |C. sensitivity. |D. latitude. ^A. The image of the hole although can be affected by contrast this is not the requirement here. ^B. Poor definition can make the image hard to discern, but the radiograph may still have sensed the penetrameter hole. ^C. TRUE! Even if the latitude of the radiograph is wide or
narrow, or the contrast and definition shoddy the imaging of the penetrameter hole is a measure of radiographic sensitivity. ^D. This is referring to the film latitude or exposure range. This has nothing to do with how sensitive a radiograph is to the hole. 112) The primary parts of an atom are: \D |A. proton, neutrino, electron. |B. proton, electron, gamma ray. |C. photon, electron, neutron. |D. proton, electron, neutron. ^A. No neutrinos. ^B. Gamma rays are not a primary, but we'd all be irradiating ourselves with our bodies which are made up of atoms. ^C. No photons. These are packets of electromagnetic radiation. ^D. YOU BET! These are the primary atomic parts there are many others which are very small, but do not concern us here. 113) X-rays and gamma rays always travel: \C |A. in pairs. |B. orbital spheres. |C. straight lines. |D. none of the above. ^A. X- and gamma rays travel in independent energy packets known as photons. They travel in a direct line from their source until collisions or gravity alter their course. ^B. If they traveled in circles or orbital spheres how can they go straight through an object to create an image on film? ^C. SURE! According to Sir Isaac Newton they will continue traveling in a straight line forever, until a collision or gravity affects their course. ^D. There is one straight and true blue answer. 114) A large source size can be compensated for by: \A |A. increasing the source-to-specimen distance. |B. addition of lead screens. |C. increasing the specimen-to-film distance. |D. increasing penumbra. ^A. YEP! By using the inverse square law doubling the distance decreases the radiation by 2 squared (2x2) or a factor of 4. ^B. This will only eliminate the soft X-rays and not substantially reduce the hard short wavelength more penetrating X-ray. ^C. This will result in a radiograph with poor definition due to the increase geometric distortion. ^D. This is the same as answer C. Increasing the penumbra shadow reduces definition and would be defeating your purpose of trying to obtain the sharpest image possible. 115) Radiation arising directly from the target of an x-ray tube or an accelerator, or from a radioactive source, is usually referred to as: \B |A. secondary radiation. |B. primary radiation. |C. backscatter. |D. inherent radiation. ^A. This is radiation that includes Compton scattering and is produced after the X-rays exit the tubes or accelerator.
^B.
YOU'RE RIGHT! They are also known as Bremsstrahlung (German for braking.) X-rays. ^C. Backscatter takes place after the X-rays have exited the tube and passed through the specimen. ^D. Radioisotopes inherently emit radiation, but there are no inherent X-rays. Think of "first" X-rays. 116) To produce X-rays, electrons are accelerated to a high velocity by an electrical field and then suddenly stopped by a collision with a solid body. This body is called: \C |A. cathode. |B. filament. |C. target. |D. generator. ^A. The cathode is where the electrons travel from. ^B. The filament is at the cathode and is the source of the accelerating electrons. ^C. CORRECT! A target material at the anode then emits a spectrum of X-rays whose minimum wavelength is controlled by the kilovoltage. ^D. A generator generates electrons or electricity which is used in X-radiographs to create X-rays. 117) The best x-ray efficiency is produced when the target material has: \B |A. a low atomic number. |B. a high atomic number. |C. a low hardness. |D. a high hardness. ^A. Elements with low atomic numbers are light and less dense making them poor X-ray emitters. ^B. ALRIGHTY! elements with high atomic numbers are the heavier, more dense elements and make excellent X-ray emitters. ^C. Hardness has nothing to do with it. Tungsten makes an excellent target material it is dense and very hard. ^D. Hardness has nothing to do with it. Gold makes an excellent target material. It is dense, but not hard. 118) What is sometimes used to change the alternating current from the high voltage transformer to direct current for the purpose of increasing the X-ray machine output? \A |A. Rectifier. |B. Cathode x-ray tubes. |C. Gas x-ray tube. |D. Vacuum x-ray tube. ^A. YES SIREEBOB! ^B. No, all X-ray tubes have a cathode. This is not a tube. ^C. No, the X-ray tube has nothing to do with the conversion of AC to DC. ^D. No, the X-ray tube has nothing to do with the conversion of AC to DC. 119) In a fluoroscopic inspection system using a 15 inch source-to-material distance and 2 inch material-to-screen distance, transverse vibration of which item will cause the most image blurring? \C |A. Source vibration. |B. Screen vibration.
|C. |D. ^A.
Material vibration. Equal effects. The source should not vibrate and should be in a fixed position. Even so source vibration does not create the most image blurring. ^B. The screen should not vibrate and should be in a fixed position. ^C. AYE! The source and screen are in a fixed position and should not vibrate; however their vibrating does not create the most image blurring. ^D. One has a more pronounced effect on blurring. 120) If a fluorescent screen is accidentally exposed to unattenuated x-rays, which of the following occurs? \C |A. Intense heat generated in the screen will permanently destroy the screen crystals. |B. Screen blackens due to overexposure. |C. The screen is essentially undamaged. |D. Screen sensitivity and light level will be permanently reduced. ^A. This is simply not true. X-rays do not generate any significant amount of heat in the materials they strike. ^B. You are thinking of the photographic effect on film which is used only once. Fluorescent screens are used over and over and repeated exposures leave them virtually unchanged. ^C. RIGHT ON! If the screen were greatly effected by attenuated or unattenuated X-rays their repeated use would be severely limited and this is not the case. ^D. This depends on the length of exposure which would have to be very long to cause a permanent change in the screen sensitivity. 121) Which of the following is an advantage of a fluoroscopic system when compared to a radiographic system? \B |A. Screens do not absorb scattered radiation so the image density is enhanced. |B. Live image presentation for immediate viewing. |C. Screen systems exhibit superior sensitivity and resolution to films. |D. The equipment is normally not portable. ^A. This is incorrect. They do absorb scattered radiation and image density is a term referring to film. ^B. CORRECTO MUNDO! A "real-time" radiographic system has many advantages including eliminating on going film and development cost, but lacks the sensitivity of film. ^C. This is totally the opposite of the truth. They have less sensitivity and resolution. ^D. This is true, but is not an advantage. 122) A fluoroscopic installation utilizing fluorescent screen requires: \B |A. A screen support with lead foil screens to control scatter. |B. Lead glass, mirrors, or other means for transmitting the fluorescent image without subjecting the operator to x-radiation. |C. Both of the above. |D. Neither of the above. ^A. Lead foil screens are used in film radiography and do not offer much protection. ^B. YES INDEEDY! These are needed to shield and protect the operator from nonconverted X-rays passing through the
screen. Do you need lead foil screens? One is correct and used to protect the operator from nonconverted X-rays that could pass through the screen. 123) In performing fluoroscopic examination of a part, it is important to control: \D |A. geometry. |B. scatter radiation. |C. source kilovoltage and milliamperage. |D. all of the above. ^A. What about scatter radiation? ^B. What about kilovoltage and milliamperage? ^C. What about geometry. ^D. O.K.! Geometry, scatter radiation, kilovoltage, and milliamperage are all important control factors in fluoroscopy. 124) In X-radiography, the ability to penetrate the test object is governed by: \C |A. source-to-film distance. |B. time. |C. kilovoltage. |D. milliamperage. ^A. The source to film distance is less important in X-ray penetrating ability than the subject to source distance. ^B. Exposure time is not a factor governing X-ray penetrating ability. What controls wavelength of the X-rays produced. ^C. AFFIRMATIVE! Kilovoltage determines the minimum wavelength of the spectrum of X-rays produced. Increasing kilovoltage produces short wavelength more penetrating X-radiation. ^D. Milliamperage controls the number of X-rays produced, not their penetrating ability. 125) Which of the following types of radiation is emitted by cobalt-60 and used in nondestructive testing? \B |A. Neutrons. |B. Gamma rays. |C. X-rays. |D. Alpha particles. ^A. Neutrons are not emitted by the atomic disintegration of Cobalt-60. ^B. ABSOLUTELY! Gamma rays are the result of the atomic disintegrations occurring in Cobalt-60. ^C. X-rays are produced by electrons onto a target material, bombarding not by the atomic decay of Cobalt-60. ^D. Alpha particles are composed of two protons and two neutrons or a Helium nucleus, and are emitted by Cobalt-60, but are not used for NDT. 126) The term used to describe the loss of excess energy by the nucleus of radioactive atoms is called: \A |A. decay (disintegration). |B. ionization. |C. scintillation. |D. activation. ^A. ROGER! It is the atomic decay (disintegration) that creates gamma rays which is energy lost by the material in the form ^C. ^D.
of radiation. This is caused by the energy absorbed by atoms from the Xor gamma rays outside the nucleus of a radioactive atom. ^C. This is the phenomena that lights up the screen used in fluoroscopy. ^D. Activation of what? This is not radiographic terminology. The loss of energy due to a breakdown of neutrons in the nucleus of radioactive elements. 127) X-rays, gamma rays, and alpha particles all have one thing in common-they are all: \D |A. particulate radiations. |B. electromagnetic radiations. |C. microwave radiations. |D. ionizing radiations. ^A. X- and gamma rays travel in energy packets known as photons which are not particles and are without mass. ^B. Alpha particles are not electromagnet radiation. They are particles containing a Helium nucleus and have mass. ^C. Microwaves, like X- and gamma rays, are a class of electromagnetic radiation and have wavelengths much longer than X- or gamma rays. ^D. VERY GOOD! All three are capable of ionizing (creating negative or positive ions) elements or compounds. 128) The term used to express the number of curies of radioactivity per gram or ounce of source weight is: \C |A. decay. |B. emissivity. |C. specific activity. |D. source output. ^A. Decay refers to atomic disintegration activity which directly relates to the curie, but this is the wrong answer. ^B. Emissivity can also refer to a materials ability to radiate heat and is a general term not directly related to the curie. ^C. PRECISELY! The specific activity is the curies per gram or ounce of material. One curie equals 3.7 x 1010 atomic disintegrations per second. ^D. Close, but the correct term refers to the activity of the decaying atomic nuclei. 129) Atoms, molecules, and various subatomic particles which carry either a positive or negative electrical charge are called: \C |A. photoelectrons. |B. photons. |C. ions. |D. compounds. ^A. These create the photographic action on the film, but all electrons are negatively charged. ^B. Photons are subatomic particle, but always carry a positive charge. ^C. EXACTLY! Compounds are composed of only molecules, all electrons are negative, and all protons are positive. ^D. Compounds are composed of many molecules. A single compound molecule can carry a charge. Compounds are composed of several atoms and are not subatomic particles. ^B.
