405. 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.

406. Radiographic sensitivity, in the context of the minimum detectable flaw size, depends on: D A. graininess of the film. B. the unsharpness of the flaw image in the film. C. the contrast of the flaw image on the film. D. all three of the above.

407. 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.

408. 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.

409. 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. to prolong exposure time .

410. 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.

411. 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.

412. 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.

413. 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.

414. Gamma and X-radiation interact with matter and may be absorbed by: D A. photoelectric absorption. B. Compton scattering. C. pair production. D. all of the above.

@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.

@Radiographic sensitivity, in the context of the minimum

detectable

flaw size, depends on:

\D

|A. graininess of the film.

|B. the unsharpness of the flaw image in the film.

|C. the contrast of the flaw image on the film.

|D. all three of the above.

@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.

@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.

@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.

@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.

@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.

@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.

@In performing fluoroscopic examination of a part, it is

important to

control:

|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.

@Gamma and X-radiation interact with matter and may be

absorbed by:

\D

|A. photoelectric absorption.

|B. Compton scattering.

|C. pair production.

|D. all of the above.

^A. What about positron-electron pair production?

^B. What about photoelectric absorption?

^C. What about Compton scattering?

^D. OF COURSE! These are the only three absorption phenomena

known.

@The kilovoltage applied to an x-ray tube affects:

\C

|A. the quality of the beam.

|B. the intensity of the beam.

|C. both A and B above.

|D. neither A nor B above.

^A. What about the intensity of the beam?

^B. What about the quality of the X-rays produced?

^C. PRECISELY! Kilovoltage controls the wavelength of the

X-rays produced which affects both the quality and intensity

or penetrating power.

^D. At least one is correct. Remember, kilovoltage controls

the

minimum wavelength of the X-ray spectrum produced.

@The x-ray absorption of a specimen depends on:

\C

|A. the thickness and density of the material.

|B. the atomic number of the material.

|C. both A and B above.

|D. neither A nor B.

^A. Yes, but what about the atomic number of the material?

^B. Yes, but what about the thickness and density of the

material?

^C. CORRECT!

^D. There is at least one correct answer.

@In the microradiographic technique:

\D

|A. soft X rays are usually employed.

|B. a kilovoltage range of 5 to 50 kV is usually employed.

|C. the photographic material is often finer grained than an

ordinary X-ray film.

|D. all three of the above choices are correct.

^A. Yes, but what about a KV range of 5 to 50 KV?

^B. Yes, but what about the primary use of soft X-rays?

^C. Yes, But what about the kilovoltage range?

^D. CORRECT!

@Excessive subject contrast caused when the thickness range in

the test specimen is too great for the radiation quality used

may

be corrected by:

\C

|A. increasing the kilovoltage.

|B. using a filter at the X-ray tube and increasing the

exposure

time.

|C. both A and B are methods for correcting excessive

subject contrast.

|D. decrease the exposure time.

^A. Yes, but what about using a filter?

^B. Yes, but what about increasing the voltage?

^C. CORRECT!

^D. No, you need to increase the exposure time.

@Subject contrast is affected by:

\D

|A. thickness differences in specimen.

|B. radiation quality.

|C. scattered radiation.

|D. all of the above.

^A. How about scattered radiation and its fogging effect?

^B. What about the thickness of the specimen being

radiographed?

^C. What about radiation quality?

^D. CORRECT!

@The Code of Federal Regulations requires that all shipping

containers for radioisotopes:

|B. be fire resistant.

@Attenuation of gamma rays in the energy range commonly used

for

testing takes place through:

\C

|A. photoelectric absorption.

|B. Compton absorption.

|C. both A and B.

|D. neither A nor B.

^A. What about Compton absorption?

^B. Photoelectric absorption is also possible.

^C. CORRECT!

^D. At least one is correct.

@Film selection for an X-ray exposure depends on:

\D

|A. thickness of the part.

|B. the material of the specimen.

|C. the voltage range of the X-ray machine.

|D. all of the above.

^A. What about the material density of a specimen?

^B. What about the voltage range of the machine?

^C. What about the thickness of the material?

^D. CORRECT! Part thickness, material, and voltage range of

the

X-ray machine all influence film selection.

@Lead screens are put in direct contact with the film to:

\D

|A. increase the photographic action on the film.

|B. absorb the longer wavelength scattered radiation.

|C. intensify the photographic effect of the primary more than

the scattered radiation.

|D. all of the above.

^A. What about absorbing longer wavelength radiation?

^B. What about intensifying the photographic effect of the

primary more than the scattered radiation?

^C. What about increasing the photographic action on the film?

^D. CORRECT!

@Mottling due to diffraction can be reduced and in some cases

eliminated by:

\C

|A. raising the kilovoltage.

|B. using lead foil screens.

|C. both of the above.

|D. none of the above.

^A. This will reduce mottling, but if kilovoltage is already

at

its peak, using lead foil screens will also reduce mottling.

^B. Raising the kilovoltage and increasing X-ray penetration

power will also reduce mottling.

^C. CORRECT! Both will reduce mottling by decreasing the

amount

of diffraction.

^D. At least one is correct. Mottling is caused by the

defraction of less penetrating longer wavelength X-rays.

.