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Question 1

1. Which of the following is not one of the scattering processes used for backscatter imaging?
   a. Elastic.
   b. Incoherent.
   c. Fluorescence.
   d. Resonance fluorescence.

Answer 1

b. Incoherent.

Question 2

2. Resonance fluorescence is used for the examination of thick or dense structures, but has the distinct disadvantage of possibly generating residual radioactivity. Why is this?
   a. Because the sources needed for this method have Very long half lives.
   b. Because this type of fluorescence occurs at very high energies.
   c. Because the materials best suited to this inspection are naturally radioactive.
   d. Because the radiation source used for this method is a disintegration by product.

Answer 2

b. Because this type of fluorescence occurs at very high energies.

Question 3

3. In which type of scattering is there a change of phase, but not energy?
   a. Elastic.
   b. Compton.
   c. Fluorescence.
   d. Resonance.

Answer 3

a. Elastic.

Question 4

4. Which type of scattering is used primarily for thickness measurement of very thin coatings?
   a. Resonance.
   b. Compton.
   c. Rayleigh.
   d. Fluorescence.

Answer 4

c. Rayleigh.

Question 5

5. As with elastic scattering, which other type has limited penetration and as a result is often used for material identification and sorting of alloys?
   a. Resonance.
   b. Compton.
   c. Resonance fluorescence
   d. Fluorescence.

Answer 5

d. Fluorescence.

Question 6

6. Which type of backscatter imaging method uses a chopper wheel in front of a slit collimator?
   a. Pinhole.
   b. Moving slits.
   c. Flying spot.
   d. Moving detector scanning.

Answer 6

c. Flying spot.

Question 7

7. What is the advantage of a moving slit over a pinhole?
   a. It increases throughput without sacrificing resolution in one direction.
   b. It provides high resolution in the depth direction.
   c. It views a larger area at equal resolution.
   d. It increases throughput by sacrificing resolution in two directions.

Answer 7

b. It provides high resolution in the depth direction.

Question 8

8. X-ray fluorescence measurements on thick parts use which type of scattering?
   a. Rayleigh.
   b. Fluorescence.
   c. Resonance fluorescence.
   d. Compton.

Answer 8

c. Resonance fluorescence.

Question 9

9. Why is backscatter imaging ideally suited to the examination of explosives?
   a. Explosive materials are made of organic materials that absorb little, but scatter well.
   b. Because there is little danger of an explosion.
   c. Because of the high energies involved.
   d. It provides high resolution in the depth direction.

Answer 9

a. Explosive materials are made of organic materials that absorb little, but scatter well.

Question 10

10. What makes backscatter imaging well suited to some aircraft inspections?
    a. Because depth scans can detect metal loss by corrosion.
    b. Because its energies are best suited to aluminum densities.
    c. Because it requires access to both sides of the object.
    d. Because its energies are best suited to inorganic compounds.

Answer 10

a. Because depth scans can detect metal loss by corrosion.

Question 11

1. Proper interpretation of a radiograph requires that the film interpreter have an understanding of:
   a. welder name.
   b. configuration and manufacturing process.
   c. time spent to manufacture.
   d. welding speed.

Answer 11

b. configuration and manufacturing process.

Question 12

2. Which of the following discontinuities would not be classified as a welding discontinuity?
   a. Incomplete fusion.
   b. Incomplete penetration.
   c. Slag inclusion.
   d. Cold shut.

Answer 12

d. Cold shut.

Question 13

3. Generally speaking, rounded or spherical voids resulting from trapped gas during the welding process would be identified as:
   a. slag inclusion.
   b. Wagon tracks.
   c. porosity.
   d. tungsten inclusion.

Answer 13

c. porosity.

Question 14

9. The detection of which of the following discontinuities 4. would be least affected by technique geometry?
   a. Incomplete fusion.
   b. Incomplete penetration.
   c. Cracks.
   d. Porosity.

Answer 14

d. Porosity.

Question 15

5. Localized contraction of cast metal as it solidifies and cools may result in:
   a. gas voids.
   b. cold shuts.
   c. shrinkage
   d. shell inclusion.

Answer 15

c. shrinkage

Question 16

6. Dark irregular images of varying length, density, and width on a radiograph would probably bc the result of;
   a. lack Of fusion.
   b. trapped slag.
   c. incomplete penetration.
   d. hot tears.

Answer 16

b. trapped slag.

Question 17

7. An area of incomplete welding at the root area of a weld, which normally occurs when there is a problem with heat input, improper joint design, poor fit-up, or improper electrode selection, is generally referred to
   a. incomplete fusion.
   b. wagon tracks.
   c. slag lines.
   d. incomplete penetration.

Answer 17

d. incomplete penetration.

Question 18

8. A very (almost white) indication detected in a piping joint that was welded using the tungsten inert gas process would probably be:
   a. crater pits,
   b. porosity.
   c. weld spatter.
   d. tungsten inclusion.

Answer 18

d. tungsten inclusion.

Question 19

9. Porosity in a weld may not be critical. When would a porosity condition not be considered detrimental to welds ?
   a. When not present in large quantities.
   b. When permitted by the standard.
   c. When it does not contain sharp tails.
   d. If it is not aligned in short distances.

Answer 19

b. When permitted by the standard.

Question 20

10. All welding processes have Common variables. Which of the following is not one of those variables?
    a. Source of heat.
    b. Source of shielding.
    c. Welding machine manufacturer.
    d. Source of chemical elements.

Answer 20

c. Welding machine manufacturer.

Question 21

11. ___________and reinforcement requirements are important in determining if the proper IQI was used.
    a. Surface finish
    b. Welding
    c. Thickness
    d. Heat treatment

Answer 21

c. Thickness

Question 22

12. One of the factors that affects the solidification of cast material is the:
    a. pour temperature.
    b. heat treat condition.
    c. elasticity.
    d. root opening.

Answer 22

a. pour temperature.

Question 23

13. in all forms are considered the most detrimental discontinuities because their sharp extremities act as stress concentrators.
    a. Slag inclusions
    b. Tungsten inclusions
    c. Oxides
    d. Cracks

Answer 23

d. Cracks

Question 24

14. image analysis techniques convert analogics television images into a digitized image that is further quantized in:
    a. time and space.
    b. space and intensity.
    c. distance and time.
    d. brightness and clarity.

Answer 24

b. space and intensity.

Question 25

15. Image enhancement techniques Currently used include three of the four applications listed below. Which is not an image enhancement technique? a. Edge en hancement. b. Spatial filtering. c. Unsharp masking. d. Static radiography,

Answer 25

d. Static radiography,

Question 26

1. The basic function of a fluorescent screen is to convert X-rays to light. How well it does this depends On the: a. use of projection magnification. b. use of antiscatter grids. c. fraction of incident X-rays absorbed by the screens. d. screenk level of quantum mottle.

Answer 26

c. fraction of incident X-rays absorbed by the screens.

Question 27

2. High-energy fluorescent screens are generally: a. more sensitive to electrons than X-rays. b. more sensitive to neutrons than X-rays. c. not the limiting factor in the total system gamma d. producing the highest gamma when used with thin metal filters.

Answer 27

a. more sensitive to electrons than X-rays.

Question 28

3. The importance of the modulation transfer function in evaluating systems is that the total system modulation transfer function is the product of the individual MTFs of the components. Because the modulation transfer function can be difficult to calculate, may be used as a more practical approximation. a. line spread function b. square wave response c. edge spread function d. photofluorographic units

Answer 28

b. square wave response

Question 29

4. Quantum mottle is an effect that: a. is only evident when using a charge coupled device for imaging. b. is evident at low brightness levels. c. requires very special image processing to eliminate. d. is only evident With solid-state imaging devices.

Answer 29

b. is evident at low brightness levels.

Question 30

5. Fluorescent screen gamma is: a. a measure of the contrast ratios between the output screen image brightness and the input radiation intensity b. equally dependent on the electron chain gamma and quantum fluctuations. c. not a practical parameter in the actual use of fluorescent screens. d. the least important element in describing screen effictiveness

Answer 30

a. a measure of the contrast ratios between the output screen image brightness and the input radiation intensity

Question 31

6. Scintillators can be used in thicknesses not possible with phosphors because a. scintillators are transparent to their own emissions. b. they are solid-state devices that do not rely on an electrochemical fuction. c. scintillators are not limited in spatial resolution by material vain size. d. quantum mottle is not a factor.

Answer 31

a. scintillators are transparent to their own emissions.

Question 32

7. Real time systems employ fluorescent screens that affect the image quality. Which of the following factors does not affect system contrast? a. Quantum fluctuation. b. Gamma of screens. c. Intensifiers. d. Television monitors.

Answer 32

a. Quantum fluctuation.

Question 33

8. In images formed by fluorescent screens: a. the control of Scatter is less important than with film images. b. unsharpness is primarily a function of the phosphor grain size and screen thickness. c. contrast and unsharpness are not as good as with real time radiography. d. few of the principles of film radiography apply.

Answer 33

b. unsharpness is primarily a function of the phosphor grain size and screen thickness.

Question 34

9. Which of the following is used to boost light intensity to a level suitable for pickup by a solid-state or television camera as the florescent screen converts radiation to light? a. An image intensifier tube. b. An electron multiplier screeny c. An image isocon tube. d. X-ray sensitive vidicon,

Answer 34

a. An image intensifier tube.

Question 35

10. What is the advantage of the vidicon image tube? a. Compatibility between beryllium and target materials, b. A small, rugged, simple tube. c. Low dynamic range. d. Used for low to medium light level applications.

Answer 35

b. A small, rugged, simple tube.