ASNT RT I EXAM STUDY GUIDE
QUESTIONS AND ANSWERS 2025
Although there may be other reasons for using calcium tungstate screens in industrial
radiography, they are most usually used to: -Correct Answer ✔Decrease exposure time
In film radiography, pentrameters are usually placed: -Correct Answer ✔on the source
side of the test object
The penetrating ability of an x-ray beam is governed by: -Correct Answer ✔Kilovoltage
Co-60 used in nondestructive testing emits: -Correct Answer ✔Gamma rays
A densitometer is an instrument for measuring: -Correct Answer ✔film density
Three liquids which are essential to process an exposed film properly are: -Correct
Answer ✔Developer, fixer and water
The two most common causes for excessively high-density radiographs are: -Correct
Answer ✔overexposure and underdevelopment
the time required for one-half of the atoms in a particular sample of radioactive material
to disintegrate is called: -Correct Answer ✔a half- life
What does the term R/h refer to when speaking of intensity? -Correct Answer
✔Roentgens per hour
The ability to detect a small discontinuity or flaw is called: -Correct Answer
✔radiographic sensitivity
Movement, geometry, and screen contact are three factors that affect radiographic: -
Correct Answer ✔unsharpness
The difference between the densities of two areas of a radiograph is called: -Correct
Answer ✔radiographic contrast
The most widely used unit of measurement for measuring the rate at which the output of
a gamma ray source decays is the: -Correct Answer ✔curie
Exposure to x-rays or gamma rays will have what effect on the body? -Correct Answer
✔It 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. 1.5 - 15R
B. 25 - 70R
C. 200 - 800R
D. All of the above doses would most likely be fatal -Correct Answer ✔C. 200 - 800 R
When doing gamma ray radiography with high- intensity emitters, the sources are best
handled: -Correct Answer ✔by remote handling equipment
If a film is placed in a developer solution and allowed to develop without any agitation: -
Correct Answer ✔There will be a tendency for areas to affect each other
The selection of the proper type of film to be used for the x-ray examination of a
particular part depends on: -Correct Answer ✔the thickness of the part, the material of
the specimen, the voltage range of the available x-ray machine
A Co-60 source has a half life of: -Correct Answer ✔5.3 Years
x-ray tube current is controlled by: -Correct Answer ✔the current passing through the
filament
The voltage and waveform applied to the x-ray tube by a high- voltage transformer
primarily determines the: -Correct Answer ✔penetrating ability
lead foil in direct contact with x-ray film: -Correct Answer ✔Intensifies the primary
radiation more than the scatter radiation
Fluorescent intensifying screens are usually mounted in pairs in rigid holders called: -
Correct Answer ✔Cassettes
Radiographic sensitivity, in the context of the minimum detectable flaw size, depends
on: -Correct Answer ✔graininess of the film, the unsharpness of the flaw image in the
film and the contrast the flaw image on the film
In order to decrease geometric unsharpness: -Correct Answer ✔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: -Correct Answer ✔x-rays of
shorter wavelength and more penetrating power are produced
In order to increase the intensity of the x-radiation: -Correct Answer ✔the tube current
should be increased
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