Quiznetik

Non Destructive Testing and Evaluation | Set 6

1. Most industrial X ray machines contain targets made of:

Correct : D. Tungsten

2. The effects of scattered radiation may be lessened by:

Correct : D. All of the above

3. A reaction which occurs when a radiation beam of 500 keV is partially absorbed by a test piece would probably be:

Correct : A. The Compton effect

4. The term used to describe the reaction of human cells, other than reproductive cells, to ionizing radiation is:

Correct : B. Somatic effects

5. A low density image of the letter ‘B’ on a radiographic film would probably be caused by:

Correct : C. Excessive backscatter

6. A term which refers to the sharpness of the radiographic image is:

Correct : D. Definition

7. A dark, irregular indication which is located adjacent to the toe of the weld would probably be:

Correct : A. Undercut

8. A term which refers to the smallest detail visible in a radiograph is called:

Correct : A. Radiographic sensitivity

9. Which type of gamma ray source would be used to radiograph a weld in 150 mm thick steel plate?

Correct : B. Co-60

10. Generally, X ray output is changed by changing the:

Correct : B. Tube current of the unit

11. Deep scratches on lead intensifying screens will cause?

Correct : B. Irregular light lines on the film

12. Which of the following is classified as electromagnetic radiation?

Correct : D. All of the above

13. The main disadvantage of having a small focal spot on an X ray tube is:

Correct : C. A smaller focal spot is limited to lower tube currents because of the potential damage from overheating

14. Exposure of whole body to moderate radiation doses of 500 – 2000 mSv (50 to 200 rem) would probably cause which of the following effects?

Correct : D. All of the above

15. A reaction which occurs when a radiation beam of 90 keV is totally absorbed by a test piece would probably be:

Correct : B. The photoelectric effect

16. The term used to describe the reaction of human reproductive cells, to ionizing radiation is:

Correct : A. Genetic effects

17. How is the wavelength of scattered radiation related to the primary beam?

Correct : A. Longer

18. Higher X ray tube voltages result in:

Correct : D. All of the above

19. Betatrons are used to produce X rays having energy in the range of:

Correct : A. Several MeV

20. A linear accelerator is used to produce X rays in what range?

Correct : A. Several MeV

21. For a particular isotope, gamma radiation intensity is determined by:

Correct : C. Source strength in curies

22. A term used to describe the range of radiation intensities falling on the film during exposure is:

Correct : B. Radiographic contrast

23. An expression which is used to describe the slope of a film characteristic curve is:

Correct : D. Film gradient

24. Which of the following factors affect film graininess?

Correct : D. All of the above

25. The amount of radioactivity which corresponds to 3.7 × 1010 disintegrations per second is called:

Correct : C. 37 GBq (1 curie)

26. The result of filtering the X rays is to produce:

Correct : D. Harder radiation

27. Which of the following actions is performed by lead screens?

Correct : D. All of the above

28. The total radiation dose received equals:

Correct : C. Radiation intensity times time of exposure

29. Which of the following is the most common type of X ray tube?

Correct : A. Bipolar

30. A reaction which occurs when a radiation beam of 15 MeV is partially absorbed by a test piece would probably be:

Correct : C. Pair production

31. A reaction which occurs when a radiation beam of 50 keV is partially absorbed by a test piece would probably be:

Correct : B. The photoelectric effect

32. A lethal dose of complete body radiation is normally considered to be:

Correct : C. 6-8 Sv (600-800 rem)

33. Almost all gamma radiography today is done with artificially activated:

Correct : B. Isotopes

34. A Curie (37 gigabecquerel)of radioactive material will disintegrate at the rate of:

Correct : B. 37 billion (3.7 × 1010) disintegrations per second

35. The specific activity of radioactive isotopes is measured in:

Correct : C. Ci/g (curies per gram) or Becquerel per gram

36. What is the primary difference between X rays and gamma rays of the same energy?

Correct : D. Origin

37. Screens should be:

Correct : C. In direct contact with the film

38. Lead foil in direct contact with the film in a cassette absorbs:

Correct : C. Long wave length radiation more than short wavelength

39. Lead screens improve mainly the of the final radiograph:

Correct : B. Contrast

40. Lead foil is placed behind the films to:

Correct : B. Reduce non image forming back-scatter

41. A filter will reduce the amount of in the primary radiation beam:

Correct : D. Low energy radiation

42. A filter is placed:

Correct : A. Between the source and the specimen

43. The tube current in milliamps multiplied by the time in seconds or minutes equals:

Correct : C. Exposure

44. If we were to maintain the same exposure but decrease the source to film distance, we must the time of exposure:

Correct : B. Decrease

45. Lead screens act as intensifiers at voltage above:

Correct : B. 150 kV

46. Use of a slower speed film improves the definition of the radiograph because the slower film:

Correct : D. Has finer grains

47. The penetrameter is a tool used to check the of a radiograph:

Correct : C. Sensitivity

48. When using a radioactive isotope in making a radiograph, we can express the equation for exposure as Ci × T. In this equation , Ci stands for:

Correct : B. Intensity in curies or becquerels

49. In the radiographic analysis procedure that is used to prepare an exposure chart, the first step is to:

Correct : A. Make a series of radiographs of a step wedge

50. Which exposure factors are recorded in the process of making a step wedge analysis?

Correct : D. All of the above

51. After the step wedge radiographs have been made, the of the image of each step is recorded on chart:

Correct : C. Density

52. The process of loading more than one film into a cassette is known as the technique:

Correct : B. Multiple film technique

53. Which of the following isotopes are commonly used for radiographic purposes?

Correct : A. Iridium-192

54. The process of being radioactive is called (Choose one):

Correct : B. Decaying

55. Which of the following types of radiation is commonly used in radiographic testing? (Choose one):

Correct : C. gamma rays

56. The amount of X radiation or gamma radiation is often spoken of as the of the radiation:

Correct : C. Intensity

57. The speed at which X and gamma rays travel is: (choose one)

Correct : A. The speed of light

58. A beam of radiation consisting of a single wavelength is known as: (choose one)

Correct : B. Monochromatic radiation

59. What governs the penetrating ability of an X ray beam?

Correct : A. Kilovoltage

60. The shorter the wavelength of X or gamma rays:

Correct : A. The higher their energy

61. ‘Photoelectric effect’ refers to:

Correct : B. Complete absorption of a photon

62. When a tissue cell in human body is damaged by radiation:

Correct : D. All of the above

63. Lead intensifying screens are used to:

Correct : A. Decrease exposure time

64. Radiographic film speed can be increased by using:

Correct : D. Lead screens versus fluorescent screens

65. A radiation producing device which emits a broad spectrum of wavelengths is:

Correct : B. An X ray machine

66. The primary effect of an increase in the milliamperage at which a X ray tube is being operated would be to:

Correct : A. Increase the radiation intensity

67. The primary effect of an increase in the kilovoltage at which a X ray tube is being operated would be to:

Correct : B. Increase penetrating power

68. Which of the following types of intensifying screens are used in industrial radiography?

Correct : A. Lead

69. A change in which of the following parameters would necessitate the construction of a new X ray exposure chart?

Correct : A. X ray machine used

70. The ASTM penetrameter for a 25 mm thick test piece contains holes of what sizes?

Correct : C. T, 2T, 4T

71. The minimum size hole in an ASTM penetrameter is:

Correct : B. 0.254 mm (0.010 inches)

72. A radiographic sensitivity level of 2-2T means that:

Correct : B. The 2T hole in a penetrameter which is 2% of the test piece thickness must be visible on the film

73. What is the most desirable temperature for manual developer solutions?

Correct : B. 20oC (68oF)

74. What is the longest period of time which should elapse between complete changes of developer solution?

Correct : D. 3 months

75. A possible result of failing to use a stop bath during manual development is:

Correct : A. Streaking of the film

76. Mottled film may result from:

Correct : D. Any of the above

77. Radiography of tubular sections using a double wall, double viewing technique is mainly applicable to sections:

Correct : C. 125 mm in diameter and less

78. A thin, white line within the film image of a weld crown might be:

Correct : A. A hair between the lead screen and the film

79. Increasing the kV setting on an X ray machine increases the:

Correct : A. Penetrating power

80. During the manufacturing of a casting, the purpose of a riser is:

Correct : B. To provide additional molten metal to allow for shrinkage during solidification

81. An effective method of recognising a film artifact is:

Correct : B. Viewing film in reflected light from a viewer

82. The main reason for using a casting is that:

Correct : D. None of the above

83. A change in which of the following parameters would require a new X ray exposure chart?

Correct : B. Required film density

84. Static marks on radiographic film are caused by:

Correct : C. Poor film handling technique

85. Of the following radiographic sources, which emits the most penetrating radiation?

Correct : A. Co-60

86. Which of the following techniques would probably reduce the amount of back scattered radiation reaching the film during a radiographic exposure?

Correct : B. Backing the cassette with a sheet of lead

87. Radiographic contrast is dependant on:

Correct : D. All of the above

88. A plot of film density versus log of relative exposure is called:

Correct : D. All of the above

89. The most common material used for targets in X ray tubes is:

Correct : A. Tungsten

90. A dark crescent shaped spot, clearly in the base metal adjacent to a weld would probably be:

Correct : B. Film crimp mark

91. Which of the following are potential sources of scattered radiation?

Correct : D. All of the above

92. If the required exposure time for a 2220 GBq (60 curie) Ir-192 source is 2 minutes, what exposure time would be required at 1110 GBq (30 curie) source:

Correct : D. 4 minutes

93. An advantage of a larger grain film is:

Correct : A. It has higher speed

94. How does radiation intensity change with increasing distance from the source?

Correct : B. Inversely with the square of distance

95. A weld discontinuity which consists of unmelted joint surfaces at the root, and which may be caused by poor fit- up, is called:

Correct : C. Incomplete penetration

96. Mottling due to X ray diffraction can be identified by:

Correct : B. Noting a slight change between two successive exposures with the test piece rotated slightly about the beam axis

97. Which of the following welding discontinuities would be considered the most serious?

Correct : C. Crack

98. A depression at the edge of a weld where the base metal has been melted during welding is called:

Correct : B. Undercut

99. Which of the following would not be considered a film artifact?

Correct : A. Sugar

100. Gamma ray or high voltage X ray radiography, using film without lead screens, is likely to result in:

Correct : A. Mottling of the film