Radiographic Testing Method

Level II
1. Low voltage X-Ray tubes are generally fitted with windows made of:
A. Plastic
B. Beryllium
C. Glass
D. Lead

2. If it were necessary to radiograph a 18 cm (7 in) thick steel product, which of the following
gamma ray sources would most likely be used?
A. Co-60
B. Tm-170
C. Ir-192
D. Cs-137

3. Co-60 is reported to have a half-life of 5.3 years. By how much should exposure time be increased
(over that used initially to produce excellent radiographs when the Co-60 source was new) when
the source is two years old?
A. No change in exposure time is needed
B. Exposure time should be about 11 percent longer
C. Exposure time should be about 31 percent longer
D. Exposure time should be about 62 to 100 percent longer

4. A sourse of Ir-192, whose half –life is 75 days, provides and optimum exposure of a given test
object today in a period of 20 minutes. Five months from now, what exposure time would be
required for the same radiographic density, under similar exposure conditions?
A. 10 minutes
B. 20 minutes
C. 1 hour and 20 minutes
D. 6 hours

5. The gamma ray intensity at 30 cm (1 ft) from a 37 GBq (1 Ci) source of radioactive Co-60 is nearest
to:
A. 15 roentgens per hour
B. 1,000 roentgens per hour
C. 1 roentgen per minute
D. 10 milliroentgens per day
6. The quantity of radiation which will produce, by means of ionization, one electrostatic unit of
electricity in 0.001293 g of dry air is known as a:
A. Millicurie
B. Gamma
C. Roentgen
D. Curie

7. Which of the following isotopes has the longest half-life?

A. Tm-170
B. Co-60
C. Ir-192
D. Cs-137

8. The slope of a straight line joining two points of specified densities on a characteristic curve of a
film is known as the:
A. Speed of the curve
B. Latitude
C. Average gradient
D. Density

9. An X-Ray film having wide latitude also has, by definition:

A. Poor definition
B. Low contrast
C. High speed
D. None of the above

10. Thin sheets of lead foil in intimate contact with X-Ray film during exposure increases film density
because they:
A. Fluoresce and emit visible light which helps expose the film
B. Absorb the scattered radiation
C. Prevent backscattered radiation from fogging the film
D. Emit electrons when exposed to X- and gamma radiation which help darken the film

11. An X-Ray tube is rated for a maximum of 250 kVp. This tube may be operated at a maximum of:
A. 250,000 V peak voltage
B. 250 kV effective voltage
C. 250,000,000 V rms voltage
D. 250 kV average voltage

12. When radiographing to the 2-2T quality level, an ASTM penetrameter for 63 mm (2.5 in) steel has
a thickness of: Example: 2.5 X .02 X 1,000 = 50 mils
A. 13 mm (0.5 in)
B. 64 µm (2.5 mils)
C. 127 µm (5 mils)
D. 1270 µm (50 mils)

13. A good Co-60 radiograph is made on a 76 mm (3 in) steel casting using an exposure time of 10
minutes and a source-to-film distance of 91 cm (36 in). If it is necessary to chang the source-to-
film distance to 61 cm (24 in), what exposure time would produce a similar radiograph if all other
conditions remain the same?

A. 1.6 minutes
B. 4.4 minutes
C. 6.4 minutes
D. 8.8 minuts

14. When sharp, black, bird-foot shaped marks which are known not to correspond with any
discontinuities appear at random on radiographs, they are probably caused by:
A. Prolonged development in old developer
B. Exposure of the film by natural cosmic ray showers during storage
C. Static charges caused by friction
D. Inadequate rinsing after fixing

15. An ASTM penetrameter for use when inspecting a 13 mm (0.5 in) thick steel plate to the 2-2T
quality level using a 41 cm (16 in) source-to-film distance would be made of:
Example: .5 X .02 X 1000 = 10 mil
A. 127 µm (5 mil) thick aluminum
B. 1270 µm (50 mil) thick aluminum or steel
C. 254 µm (10 mil) thick steel
D. 51 µm (2 mil) strip of any metallic material

16. Besides serving as a filter, screens of high atomic numbers, such as lead and lead antimony, also:
A. Decrease the source-to-film distance needed for a proper radiograph
B. Provide some image intensifying action
C. Permit the use of higher speed film
D. Decrease the graininess in a radiograph

17. X-Ray films with large grain size:

A. Will produce radiographs with better definition than film with small grain size
B. Have slower speeds than those with a relatively small grain size
C. Have higher speed than those with a relatively small grain size
D. Will take longer to expose properly than film with relatively small grain size

18. As the effective energy of the radiation increases up to abut 250 kV:
A. Film graininess increases
B. Film graininess decreases
C. Radiographic definition increases
D. Film speed decreases

19. Two isotropic sources of a given strength have two different specific activity values. The source
with the higher specific activity value will:
A. Have a smaller physical size than the source with a lower specific activity
B. Have a shorter half-life than the source with a lower specific activity
C. Produce harder gamma rays than the source with a lower specific activity
D. Have a larger physical size than the source with the lower specific activity
20. In general, the quality of fluoroscopic equipment is best determined by:
A. Densitometer readings
B. Penetrameter sensitivity measurements
C. Discontinuity area measurements
D. Reference standards

21. A general rule governing the application of the geometric principles of shadow formation states that
the:
A. X-Rays should proceed from as large a focal spot as other considerations will allow
B. Distance between the radiation source and the material examined should be as small as practical
C. Film should be as far as possible from the object being radiographed
D. Central ray should be as nearly perpendicular to the film as possible to preserve spatial
relationships

22. The radiographic absorption of a material will tend to become less dependent upon the
composition of the material when:
A. The kilovoltage is increased
B. The source-to-film distance is decreased
C. The kilovoltage is decreased
D. A filter is used

23. The formula (milliamperes X time) + distance² is:

A. Used to calculate film gradient
B. The reciprocity law
C. Used to determine radiographic contrast
D. The exposure factor

24. X-Ray exposure holders and cassettes often incorporate a sheet of lead foil in the back which is
not in intimate contact with the film. The purpose of the sheet of lead foil is:
A. To act as an intensifying screen
B. To protect the film from backscatter
C. Both A and B
D. Neither A nor B

25. A lead sheet containing a pinhole may be placed halfway between the X-Ray tube and the film in order
to:
A. Determine the approximate size of the focal spot
B. Measure the intensity of the central ray
C. Filter scatter radiation
D. Soften the X-Radiation

26. In certain cases, it may be advantageous to pack lead shot around a specimen. The purpose for
doing this is to:
A. Prevent movement of the specimen
B. Increase the subject contrast
C. Generate smaller wavelength X-Radiation
D. Decrease the effect of scattered radiation undercutting the specimen

27. A radiograph made with an exposure of 12 mA per minute has a density of 0.8 in the region of
maximum interest. It is desired to increase the density to 2.0 in this area. By reference to a
characteristic curve of the film, it is found that the difference in log E, Between a density of 0.8 and
2.0 is 0.76. the antilogarithm of log 0.76 is 5.8. what must the new exposure time be to produce a
radiograph with a density of 2.0?
A. 9.12 mA per minute
B. 21.12 mA per minute
C. 69.6 mA per minute
D. 16 mA per minute

28. The absorption of radiation by a material varies:

A. Directly with the square of the distance from the source
B. With the thickness of the material
C. Inversely with the amount of scattering in the material
D. In an approximately exponential manner with the thickness of the material

29. In order for a radiograph to have a penetrameter sensitivity of 2-2T or better:

 A. The radiographic procedure has to be able to differentiate a 2 percent difference in specimen
thickness
B. The radiographic procedure must be able to define the 2T hole in a penetrameter which is 2
percent of the thickness of the specimen
C. The radiograph must be able to distinguish a discontinuity with a length equivalent to 2 percent of
the specimen thickness
D. None of the above

30. For practical purposes, the shape of the characteristic curve of an X-Ray film is:
A. Independent of the type of film used
B. Independent of the quality of X- or gamma radiation
C. Drastically change when the quality of the X-Ray radiation is changed
D. Primarily determined by the subject contrast

31. The interval between the time a film is placed in a fixer solution and the time when the original
diffuse, yellow milkiness disappears is known as:
A. Clearing time
B. Fixing time
C. Hardening time
D. Oxidation time
A. 1 MeV

32. The activity of the fixer diminishes after being used for a period of time because the:
A. Activity ingredients evaporate
B. Active ingredients are absorbed by the radiograph
C. Fixer solution accumulates soluble silver salts
D. Active ingredients settle to the bottom of the tank

33. As the development time increases

A. The characteristic curve grows steeper and moves to the left
B. The characteristic curve grows steeper and moves to the right
C. The characteristic curve remains the same in shape but moves to the left
D. There is little effect on the characteristic curve

34. A distinctive characteristic of high-voltage radiography is that:

A. It results in comparatively high subject contrast
B. It results in comparatively high radiographic contrast
C. It is applicable to comparatively thick or highly absorbing specimens
D. All of the above are distinctive characteristics of high-voltage radiography
35. Which of the following is not a factor in determining subject contrast
A. Nature of the specimen
B. The radiation quality used
C. Type of film used
D. Intensity and distribution of the scattered radiation

36. If a specimen is radiographed at 40 kV and again at 50 kV with time compensation to give the
radiographs the same density, which of the following statements would be true?
A. The 40 kV exposure would have a lower contrast and a greater latitude than the 50 kV exposure
B. The 40 kV exposure would have a higher contrast and a greater latitude than the 50 kV exposure
C. The 50 kV exposure would have a lower contrast and a greater latitude than the 40 kV exposure
D. The 50 kV exposure would have a higher contrast and a greater latitude than the 40 kV exposure

37. Film selection for an X-Ray exposure depends on:

A. The thickness of the part
B. The material of the specimen
C. The voltage range of the X-Ray machine
D. All of the above

38. If 3.7 GBq (1 Ci) of Ir-192 produces a dose rate of 5,900 mR/h at 0.3 m (1 ft), how many mR will 3,700
GBq (10 Ci) produce at the same distance?
A. 590
B. 590,000
C. 59
D. 59,000

39. Source size, specimen thickness, and source-to-specimen distance are the three factors that determine
the:
A. Density of the radiograph
B. Exposure of the radiograph
C. Film size
 D. Unsharpness recorded on the radiograph

40. The half-life of radioactive Cs-137 is nearest to:

A. 36 days
B. 6 years
C. 30 years
D. 526 days