RT / X-ray Level I Flashcards by Michael Shigley

Although there may be other reasons for using calcium tungstate screens in industrial radiography, they are most often used to:

a. improve definition and resolution in radiographic images
b. improve contrast in radiographic images
c. decrease exposure time
d. make films respond to multimillion volt radiation

c. decrease exposure time

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An excellent radiograph is obtained under given conditions of exposure with the film located at a distance of 36 in. from the target of the X-ray tube. If the film is now placed only 18 in. from the target, and all exposure conditions except time are held constant, the new exposure time will be:

a. unchanged
b. longer by approximately 80%
c. shorter by approximately 55%
d. only about 25% as long as the original exposure time

d. only about 25% as long as the original exposure time

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An excellent radiograph is obtained under given exposure conditions with a tube current of 5 mA and an exposure time of 12 min. If other conditions are not changed, what exposure time would be required if the X-ray tube current could be raised to 10 mA?

a. 24 min
b. 12 min
c. 6 min
d. 3 min

c. 6 min

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In film radiography, image quality indicators (penetrameters) are usually placed:

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

b. on the source side of the test object

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When radiographing to the 2-2T quality level, an ASTM image quality indicator (IQI) for 0.5 in. thick 2024 aluminum alloy has a thickness of:

0.010 in.

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The penetrating ability of an X-ray beam is governed by:

a. kilovoltage
b. time
c. milliamperage
d. source-to-film distance

a. kilovoltage

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Co-60 used in nondestructive testing emits:

gamma rays

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A densitometer is an instrument for measuring:

film density

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Three liquids which are essential to process an exposed film properly are:

developer, fixer and water

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The two most common causes for excessively high density radiographs are:

overexposure and overdevelopment

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The time required for one-half of the atoms in a particular sample of radioactive material to disintegrate is called:

a half-life

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What does the term R/h refer to?

roentgen per hour

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The ability to detect a small detail is called radiographic:

sensitivity

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The difference between the densities of two areas of a radiograph is called:

a. radiographic contrast
b. subject contrast
c. film contrast
d. definition

a. radiographic contrast

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The unit of measurement used for the output of a gamma ray source is the:

becquerel (curie)

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Exposure to X-rays or gamma rays:

a. may have a cumulative effect which must be considered
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. may have a cumulative effect which must be considered

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Which dose would be dangerous, if not fatal, if applied to the entire body in a short period of time?

a. 15-150 mSv (1.5-15 R)
b. 250-700 mSv (25-70 R)
c. 5000-8000 mSv (500-800 R)
d. all of the above doses would most likely be fatal

c. 5000-8000 mSv (500-800 R)

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When doing gamma ray radiography with high-intensity emitters, the sources are best handled:

by remote handling equipment

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If a film is placed in a developer solution and allowed to develop without any agitation:

a. the radiograph may not show proper contrast
b. it will be impossible to fix the radiographic permanently
c. there will be a general “fogging” condition over the entire radiograph
d. uneven development or streaking could occur

d. uneven development or streaking could occur

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The selection of the proper type of film to be used for the X-ray examination of a particular part depends on:

a. the thickness of the part
b. the material of the specimen
c. the voltage range of the available X-ray machine
d. all of the above

d. all of the above

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A Co-60 source has a half-life of:

5.27 years

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X-ray tube current is controlled by:

a. the current passing through the filament
b. the distance from the cathode to the anode
c. the type of material used in the target
d. the voltage and waveform applied to the X-ray tube

a. the current passing through the filament

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Lead foil in direct contact with X-ray film:

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

c. intensifies the primary radiation more than the scatter radiation

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Lead intensifying screens are usually mounted in pairs in rigid holders called:

cassettes

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In order to decrease geometric unsharpness: 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. radiation should proceed from as small a focal spot as other considerations will allow

As the kilovoltage applied to the X-ray tube is raised: 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

b. X-rays of shorter wavelength and more penetrating power are produced

In order to increase the intensity of X-radiation: a. the tube current should be increased b. the tube current should be decreased c. the test specimen should be moved farther from the film d. a lower kilovoltage should be applied to the tube

a. the tube current should be increased

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: a. radiation imaging b. spotting c. undercut d. unsharpness

c. undercut

Scattered radiation caused by any material, such as a wall or floor, on the film side of the specimen is referred to as:

backscattered radiation

Which of the following materials is suitable for use in containers used to mix processing solutions?

stainless steel

Of the following, which would be especially sensitive to injury by excessive exposure to X-rays or gamma rays? a. blood b. lens of the eye c. internal organs d. all of the above

d. all of the above

Film overexposure from X-ray radiography may be caused by: a. the direct beam from the X-ray tube target b. scatter radiation arising from the objects in the direct beam c. residual radiation that exists for the first few minutes after X-ray machine has been returned to the "off" position d. both a and b may be causes

d. both a and b may be causes

A general rule often employed for determining the kilovoltage to be used when X-raying a part is that: 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

b. the kilovoltage should be as low as other factors will permit

If a piece of lead 0.5 in. thick is placed in the path of a beam of radiation emanating from Co-60, it will reduce the dose rate at a given location by: a. one-third b. one-quarter c. one-half d. three-quarters

c. one-half

Excessive exposure of film to light prior to development of the film will most likely result in:

a foggy film

Reticulation resulting in a puckered or net-like film surface is probably caused by: a. crimping film after exposure b. sudden extreme temperature change while processing in the developer c. water or developer on unprocessed film d. excessive object-to-film distance

b. sudden extreme temperature change while processing in the developer

Frilling or loosening of the emulsion from the base of the film is most likely caused by: a. water or developer on unprocessed film b. low temperature of processing solutions c. developer solution contamination d. warm or exhausted fixer solution

d. warm or exhausted fixer solution

If an exposure time of 60 s was necessary using a 4 ft source-to-film distance for a particular exposure, what time would be necessary if a 2 ft source-to-film distance is used and all other variables remain the same?

15 s

One of the general rules concerning the application of geometric principles of shadow formation to radiography is: 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 of the above

c. the distance between the anode and the material examined should always be as great as possible

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. This standard test piece is called:

an image quality indicator (IQI)

An IQI is used to indicate the: a. size of discontinuity in a part b. density of the film c. amount of film contrast d. sensitivity of the radiographic technique

d. sensitivity of the radiographic technique

A fluorescent intensifying screen will: a. emit light that may lessen the exposure necessary b. result in reticulation c. decrease the graininess of the image when using gamma rays d. increase the definition in a radiograph

a. emit light that may lessen the exposure necessary

The three main steps in processing a radiograph are:

developing, fixation, and washing

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: a. focal point size b. temperature c. filament-to-focal spot distance d. milliamperage

d. milliamperage

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: a. air bells b. graininess c. reticulation d. frilling

b. graininess

Static marks, which are black tree-like or circular marks on a radiograph, are often caused by:

improper film handling techniques

The purpose of agitating an X-ray film during development is to: 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

b. renew the developer at the surface of the film

When manually processing films, the purpose for abruptly tapping the hangers against the side of the tank after the films have been lowered into the developer is to: a. disperse unexposed silver grains on the film surface b. prevent frilling c. dislodge any air bubbles clinging to emulsion d. do all of the above

c. dislodge any air bubbles clinging to emulsion

The activity of the developer solution is maintained stable by: a. constantly agitating it b. heating processing solutions c. avoiding contamination from the wash bath d. adding replenisher

d. adding replenisher

The purpose of fixation is: 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

d. all of the above

Water spots on films can be minimized by: a. the rapid drying of wet film b. using a wetting agent solution c. using a fresh fixer solution d. cascading water during the rinse cycle

b. using a wetting agent solution

The small area in the X-ray tube from which the radiation emanates is called the: a. diaphragm b. focal spot c. focusing cup d. cathode

b. focal spot

The radiation quality of a gamma ray source is: a. determined by the size of the focal spot b. determined by the isotope involved c. varied by the operator d. greater in Ir-192 than in Co-60

b. determined by the isotope involved

The radiation intensity of a radioisotope: a. increases with time b. decreases with time c. is not affected as time elapses d. none of the above

b. decreases with time

A curie is the equivalent of: a. 37 Bq b. 37 GBq c. 37,000,000 TBq d. 3,700,000

b. 37 GBq

With a given exposure time and kilovoltage, a properly exposed radiograph is obtained with a 6 mA minutes exposure at the distance of 20 in. It is desired to increase the sharpness of detail in the image by increasing the source-to-film distance to 40 in. The correct milliamperage-minutes exposure to obtain the desired radiographic density at the increased distance is:

24 mA-minutes

Very short wavelength electromagnetic radiation produced when electrons travelling at high speeds collide with matter is called: a. X-radiation b. beta radiation c. gamma radiation d. none of the above

a. X-radiation

The exposure of personnel to X-radiation and gamma radiation can be measured or monitored by means of: a. film badge b. dosimeters c. radiation exposure survey meters d. all of the above

d. all of the above

Assuming that a good radiograph is obtained at a setting of 10 mA in 40 s, how much time would be necessary to obtain one equivalent radiograph if the milliamperage is changed to 5 mA (all other conditions remaining constant)?

80 s

A graph showing the relation between material thickness, kilovoltage, and exposure is called: a. a bar chart b. an exposure chart c. a characteristic chart d. a logarithmic chart

b. an exposure chart

A graph which expresses the relationship between the logarithm of the exposure applied to a photographic material and the resulting photographic density is called: a. a bar chart b. an exposure chart c. the characteristic curve d. a logarithmic chart

c. the characteristic curve

Short Wavelength electromagnetic radiation produced during the disintegration of nuclei of radioactive substances is called:

gamma radiation

A photographic image recorded by the passage of X-rays or gamma rays through a specimen onto a film is called a(n):

radiograph

In order to achieve uniformity of development over the area of an X-ray film during manual processing: a. the film should be placed in a dryer after being developed b. the developer should be agitated by using mechanical stirrers or circulating pumps c. the film should be agitated while in the developer d. the film should be transferred directly from the developer to the fixer

c. the film should be agitated while in the developer

When referring to a 2T or 4T hole in the ASTM IQI, the T refers to the: a. part thickness b. plaque thickness c. time of exposure d. time for developing

b. plaque thickness

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. mask b. filter c. backscatter absorber d. lead foil screen

a. mask

Two X-ray machines operating at the same nominal kilovoltage and milliamperage settings: 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

d. may give not only different intensities but also different qualities of radiation

Fluoroscopy differs from radiography in that: a. fluoroscopy uses 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

c. the X-ray image is observed visually on a fluorescent screen rather than recorded on a film

An advantage of the pocket dosimeter type of ionization chamber used to monitor radiation received by personnel is: 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

b. it provides an immediate indication of dosage

The density difference between two selected portions of a radiograph is known as: a. unsharpness b. radiographic contrast c. specific activity d. subject density

b. radiographic contrast

Fluorescent screens have the ability to: a. absorb electrons b. emit electrons c. increase exposure time d. none of the above

b. emit electrons

When producing radiographs, if the kilovoltage is increased, the: a. subject contrast decreases b. film contrast decreases c. subject contrast increases d. film contrast increases

a. subject contrast decreases

The accidental movement of the specimen or film during exposure or the use of a focus-film distance that is too small will: a. produce a radiograph with poor contrast b. make it impossible to detect large discontinuities c. result in unsharpness of the radiograph d. result in a fogged radiograph

c. result in unsharpness of the radiograph

Lead screens in intimate contact with the film during exposure: a. reduce exposure time and improve radiographic quality b. absorb the shorter wavelength scattered radiation more than the long wavelength primary radiation c. intensify the photographic effect of the scatter radiation more than that of the primary radiation d. none of the above

a. reduce exposure time and improve radiographic quality

The sharpness of the outline in the image of the radiograph is a measure of: a. subject contrast b. radiographic definition c. radiographic contrast d. film contrast

b. radiographic definition

An unshielded isotope source gives a dosage rate of 9000 uSv/h at 3 m (900 mR/h at 10 ft). What would the unshielded dosage rate be at 9 m (30 ft)?

1000 uSv/h (100 mR/h)

Which has the shortest wavelength? a. visible light b. microwaves c. 100 kV peak X-rays d. infrared radiation

c. 100 kV peak X-rays

Beta particles are: a. neutrons b. electrons c. positrons d. protons

b. electrons

The velocity of all electromagnetic radiation is: a. 186,000 miles per second b. 18,600 miles per second c. 186,000 miles per minute d. 1,860 miles per second

a. 186,000 miles per second

Unexposed boxes of X-ray film should be stored: a. flat b. on edge or end c. in a pile d. it does not matter

b. on edge or end

The lead symbol "B" is attached to the back of the film holder to determine:

whether excessive backscatter is present

Image quality indicators for _______ are considered Group I Materials and do not need to have an identification notch.

stainless steel

The purpose of a dated decay curve is to: 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

c. determine the source strength (activity) at any time

Why is Co-60 used as a radiation source for medium-weight metals of thickness ranges from 38.1 to 228.6 mm (1.5 to 9 in.)?

because of its penetrating ability

The cause for poor image definition could be: a. too short source-to-film distance b. screens and film not in close contact c. film graininess d. all of the above

d. all of the above

During manual film processing, the purpose of the stop bath is to:

neutralize the developer and stop the developing process

A thin metallic sheet (brass, copper, lead, etc.) placed at the source to reduce the effects of softer radiation is known as:

a filter

The reason a shim is used in a radiographic setup is to: a. improve the IQI image b. reduce diffraction c. simulate weld thickness d. intensify the image

c. simulate weld thickness

The density of a radiograph image refers to the: a. thickness of the film b. thickness of the specimen c. weight of the film d. degree of film blackening

d. degree of film blackening

Gamma radiation and X-radiation interact with matter and may be absorbed by: a. photoelectric absorption b. compton scattering c. pair production d. all of the above

d. all of the above

The image of the required image quality indicator and hole on the radiograph indicates that the radiograph has the required:

sensitivity

The primary parts of an atom are:

proton, electron, and neutron

X-rays and gamma rays travel in:

straight lines

A large source size can be compensated for by:

increasing the source-to-specimen distance

Radiation arising directly from the target of an X-ray tube or an accelerator, or from a radioactive source, is usually referred to as: a. secondary radiation b. primary radiation c. backscatter d. inherent radiation

b. primary radiation

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 a: a. cathode b. filament c. target d. generator

c. target

The best X-ray efficiency is produced when the target material has a: a. low atomic number b. high atomic number c. low hardness d. high hardness

b. high atomic number

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. rectifier b. cathode X-ray tubes c. gas X-ray tube d. vacuum X-ray tube

a. rectifier

In X-radiography, the ability to penetrate the test object is governed by: a. source-to-film distance b. time c. kilovoltage d. milliamperage

c. kilovoltage

Which of the following types of radiation is emitted by Co-60 and used in nondestructive testing?

gamma rays

The term used to describe the loss of excess energy by the nucleus of radioactive atoms is called:

decay (disintegration)

X-rays, gamma rays, and alpha particles all have one thing in common; they are all: a. particulate radiations b. electromagnetic radiations c. microwave radiations d. ionizing radiations

d. ionizing radiations

The term used to express the number of curies of radioactivity per gram or ounce of source weight is: a. decay b. emissivity c. specific activity d. source output

c. specific activity