with Guaranteed Pass Solutions.
Cesium 137 - Answer In practical radiography, with only one exception, all exposing radiation
is polychromatic. Which of the sources of radiation used is not polychromatic?
Atomic number, density, and thickness of the specimen - Answer The absorption of gamma
rays from a given source when passing through matter is dependent on the:
Iridium 192 - Answer Of the following radioisotopes which has the greatest number of
gamma rays?
5500 A - Answer Fluoroscopic screens are typically coated with phosphors such as zinc sulfide
or zinc cadmium sulfide, which produce visible yellow-green light with a wavelength of
approximately:
4.22 R/hr - Answer How many R/hr could be expected at a film placed 4 m from Co-60 source
after 5.3 years? The original activity of the source was 100Ci.
The fluoroscopic image is positive whereas the radiographic image is a negative transparency. -
Answer A basic difference between a radiograph and fluoroscopic image is:
They travel in a straight line at the velocity of light. - Answer Which of the following are X-ray
and gamma ray characteristics?
Increase the radiation energy - Answer One technique for compensating for a wide variation
in subject contrast is to
A panoramic exposure - Answer A technique that is commonly used for large diameter pipes
whereby an entire circumferential weld can be radiographed in one exposure is called:
Geiger Muller detector - Answer All other design parameters being equal which of the
following operates at the highest applied voltage?
Hot tears - Answer During casting of a metal into a mold, cracking sometimes occurs due to
the shape and rigidity of the mold and stresses set up during the cooling process which exceed
the strength of the metal. These cracks or defects appear in a radiograph as ragged dark lines
and may be;
,Radioactive half life - Answer In effective half life, what other factor must be considered in
addition to the biological half life?
For the best screen film contact - Answer Why are vacuum cassettes used to obtain the
sharpest possible images when performing radiography with screens of any type?
An amorphous, noncrystalline film of selenium - Answer The photoconductor used in
xeroradiographic X-ray image systems is;
Lymphocytes - Answer Which of the following human cell categories is most susceptible to
radiation injury?
To indicate the quality of the radiographic technique - Answer A penetrameter is used:
Densitometric comparison and visual comparison - Answer What are the 2 general
approaches to indirect thickness measurements using radiographic inspection?
The G-M tubes saturate on each pulse cycle of intense radiation, so as to count cycles only. -
Answer Geiger-Mueller (G-M) types of instruments are not suitable for use in monitoring film
exposures with betatron high energy radiation because:
Strontium-90 - Answer Of the following beta emitting radioactive sources, which is frequently
used for beta ray thickness gauging?
use 3-5 X magnifier - Answer An assembly that contains a number of very minute
components is radiographed. In evaluating the radiograph, which one of the following is most
correct?
Composite - Answer Since damage in __(blank)__ specimens do not provide the necessary X-
ray contrast, an X-ray opaque fluid should be applied to the surface of the specimen in the
damaged region.
It is necessary to use a slower scanner rate where very low radiation intensities are experienced.
- Answer Which of the following is not a true advantage of solid state cameras as opposed to
the tube type cameras used in real-time radiography:
Slit width - Answer When performing in-motion radiography, the unsharpness of the
resulting image is directly proportional to the __(blank)___ , focal spot size, and thickness of the
specimen.
, Radiographic definition - Answer On a radiograph, the sharpness of the transition between
different densities produced by sharply defined subject edges is known as:
X-ray diffraction examination - Answer The fact that each solid crystalline substance produces
its own characteristic X-ray pattern is the basis for:
Using a front and back filter - Answer The mottling caused by diffraction when radiographing
fairly large-grained metallic specimens can be reduced and, in some cases, eliminated by:
Markedly decreased exposure times - Answer When comparing fluorescent intensifying
screens with lead foil screens, their primary advantage is:
A method for determining the depth of a discontinuity within a specimen - Answer The term
parallax is usually used in radiography with regard to
Generating thermal electrons at the cathode - Answer A source of electrons is needed to
bombard a target material in a typical X-ray unit. This is accomplished by:
The way in which neutrons are removed from the inspection beam by the specimen - Answer
The major difference between neutron and X-ray radiography is:
Tungsten - Answer In a field emission tube, what material is the cathode generally made
from?
The fastest film curve is the one that lies to the left of the other curves. - Answer in a group
of film characteristic curves plotted on one graph, which of the following would be the fastest
film?
Ytterbium-169 - Answer A low energy isotope with a principal gamma peak at 52 KeV useful
for radiography of thin steel sections, light metals, plastics, and wood is:
Controls the divergence of the electron beam. - Answer What is the function of the focusing
cup of cathode assembly in an X-ray tube?
Biological half life - Answer Which of the following is best used to express the decay of
radioactive materials in the body?
Developed film density resulting from exposure and processing - Answer The gradient of a
specific radiographic film characteristic curve relating film density to the logarithm of X-ray
exposure varies primarily only with the: