Quiznetik

Non Destructive Testing and Evaluation | Set 9

1. The ability to separate echos from reflectors close together in depth is called:

Correct : A. Resolution

2. Greater depth of penetration in coarse grained material may be achieved using:

Correct : D. Lower frequencies

3. Lower frequency transducers produce:

Correct : B. Deeper penetration, less attentuation and greater beam spread

4. Spurious indications might be caused by which of the following?

Correct : A. Mode conversion from beam spread in a long specimen

5. The portion of a test piece which is represented by the CRT screen area from zero to the rightmost edge of the initial pulse is called:

Correct : B. The near field

6. The depth of penetration of surface waves is approximately:

Correct : A. One wavelength

7. An ultrasonic test using a straight beam contact search unit is being conducted through the thickness of a flat part such as a plate. This test should detect:

Correct : A. Laminar-type flaws with major dimensions parallel to the rolled surface

8. The first critical angle is defined as the longitudinal wave incident angle which results in:

Correct : A. A refracted longitudinal wave of ninety degrees

9. The number of complete waves which pass a given point in a given period of time (usually one second) is referred to as the:

Correct : C. Frequency of a wave motion

10. The speed of sound in a given material depends on:

Correct : C. The density and elasticity of the material

11. AA screen pattern containing a large number of low-level indications (often reffered to as ‘hash’) could be caused by:

Correct : C. Coarse grained material

12. In an A scan presentation, the horizontal base line represents the:

Correct : C. Elapsed time or distance

13. An ultrasonic instrument control which is used to expand or contract the horizontal base line of an A scan display is called:

Correct : A. The sweep length or range control

14. In a basic ultrasonic test pattern (A scan) for contact testing, the initial pulse (assume no sweep delay is used):

Correct : A. Is the high indication on the extreme left side of the screen that represents the entry surface of the inspected part

15. AA term used in ultrasonics to express the rate at which sound waves pass through various substances is:

Correct : B. Velocity

16. Transducer focal lengths are normally specified as:

Correct : A. Distance in steel

17. The second critical angle is defined as the longitudinal wave incident angle which results in:

Correct : B. A refracted shear wave of ninety degrees

18. Spurious or nonrelevant indications might be suspected if:

Correct : A. Indications are unusually consistent in amplitude and appearance

19. A A disadvantage of lithium sulfate as a transducer material is that:

Correct : B. It is soluble in water

20. An advantage of using a ceramic transducer in search units is that:

Correct : A. It is one of the most efficient generators of ultrasonic energy

21. The three most common modes of sound vibration are:

Correct : B. Longitudinal, transverse and rayleigh waves

22. A A larger diameter crystal results in:

Correct : C. Less beam spread

23. Entry surface resolution is a characteristic of an ultrasonic testing system which defines its ability to:

Correct : D. Detect discontinuities located just beneath the entry surface in the part being tested

24. Higher frequency transducers produce which of the following?

Correct : D. Greater sensitivity, resolution and attenuation

25. In immersion testing, verification that the search unit is normal to a flat entry surface is indicated by:

Correct : A. Maximum reflection from the entry surface

26. Which of the following is true?

Correct : D. Wavelength=velocity/frequency

27. Most commercial ultrasonic testing is accomplished using frequencies between:

Correct : B. 0.2 and 25 MHz

28. The longitudinal wave incident angle which results in formation of a rayleigh wave is called:

Correct : C. The second critical angle

29. An ultrasonic testing technique in which the transducer element is not parallel to the test surface is called:

Correct : A. Angle beam testing

30. In the same material, shear wave velocity is:

Correct : A. Approximately 1/2 longitudinal wave velocity

31. Another name for a compression wave is a:

Correct : C. Longitudinal wave

32. Under most circumstances, which of the following frequencies would result in the best resolving power?

Correct : D. 25 MHz

33. The most useful range of incident longitudinal wave angles for ultrasonic testing is:

Correct : A. Normal incidence to the first critical angle

34. Ultrasonic testing of material where the search unit is in direct contact with the material being tested may be:

Correct : D. All of the above

35. The echo on the cathode ray tube (CRT) which represents the far boundary of the material being tested is called:

Correct : D. The back wall echo

36. AA standard block which can be used to calibrate an instrument for an angle beam range calibration is:

Correct : C. V1/A2 block

37. The ability to detect echos from small reflectors is called:

Correct : D. Sensitivity

38. When the motion of the particles of a medium is parallel to the direction of propagation, the wave being transmitted is called a:

Correct : A. Longitudinal wave

39. In contact testing, the entry surface indication is sometimes referred to as:

Correct : C. Both (a) and (b)

40. A A second name for Rayleigh waves is:

Correct : D. Surface waves

41. Sound beam intensity decreases expontentially with distance in the area called:

Correct : B. The far field

42. AA test method employing two seperate search units on opposite surfaces of the material being tested is called:

Correct : C. Through-transmission testing

43. Which of the following is not (!) a requirement of a couplant?

Correct : B. Highly penetrating

44. A A plan view representation of a test piece is produced by which of the following?

Correct : C. C scan

45. A A widening of the front surface indication, when testing a rough surface, is caused by:

Correct : C. A partial reflection of ultrasonic beam side lobe energy

46. When a vertical indication has reached the maximum signal height which can be displayed or viewed on the CRT of an ultrasonic instrument, the indication is said to have reached its:

Correct : C. Vertical level

47. AA material used between the face of a search unit and the test surface to permit or improve the transmission of ultrasonic vibrations from the search unit to the material being tested is called:

Correct : B. A couplant

48. When an ultrasonic beam passes through the interface between two dissimilar materials at an angle, a new angle of sound travel is formed in the second material due to:

Correct : D. Refraction

49. The velocity of sound waves is primarily dependent on:

Correct : C. The material in which the sound is being transmitted and the mode of vibration

50. Piezoelectric ability is the property of a material to:

Correct : D. Produce an electric current when deformed and vice versa

51. The boundary between two different materials which are in contact with each other is called:

Correct : C. An interface

52. An ultrasonic insrument control which is used to adjust the sharpness of the CRT screen display is called:

Correct : A. Astigmatism or focus

53. A A disadvantage of using a low frequency ultrasonic transducer is:

Correct : D. It provides a larger beam angle and poorer resolving power

54. As transducer crystal thickness decreases:

Correct : C. Frequency increases

55. On the area-amplitude ultrasonic standard test blocks, the flat-bottomed holes in the blocks are:

Correct : B. Different in diameter, increasing by 1/64 inch increments from the No. 1 block to the No. 8 block

56. A A disadvantage of using a low frequency ultrasonic transducer is:

Correct : C. It provides a smaller beam angle and poorer resolving power

57. A A disadvantage of using a high frequency ultrasonic transducer is:

Correct : C. It is scattered more by coarse grained material

58. When a longitudinal wave sound beam passes through an acoustic interface at some angle other than zero degrees:

Correct : C. Reflection, refraction and mode conversion occur

59. The angle of a refracted shear wave generated as a sound wave passes at an angle through an acoustic interface is depentant on:

Correct : A. The acoustic impedances of the materials on each side of the interface

60. The purpose of the couplant is to:

Correct : A. Match impedances between the transducer and test piece

61. When a sound beam is reflected:

Correct : B. The angle of reflection equals the angle of incidence

62. The ability to detect echoes from small reflectors is called:

Correct : D. Sensitivity

63. The ability to separate echoes from reflectors close together in depth is called:

Correct : A. Resolution

64. Which of the following transducer materials is the most efficient receiver of ultrasonic energy?

Correct : C. Lithium sulfate

65. AA display which shows the initial pulse and the front surface echo superimposed would be considered:

Correct : B. An A scan

66. AA display which shows the initial pulse and the front surface echo with a fairly wide space between the two would be considered:

Correct : A. An immersion test

67. When conducting an immersion test, the water path distance must be controlled so that:

Correct : C. The test piece discontinuity indications appear between the first front and first back surface echos

68. Bubblers and wheel transducers are considered:

Correct : B. Modified immersion techniques

69. Most commercial ultrasonic testing is performed at frequencies between:

Correct : D. 1 MHz and 25 MHz

70. For a transducer with any given Q, resolution increases with:

Correct : B. Frequency

71. Resolving power of a transducer is directly proportional to its:

Correct : C. Bandwidth

72. The term is used to refer to the product of wave velocity and density is:

Correct : A. Acoustic impedance

73. Snell's law is given by which of the following:

Correct : B. (Sin A)/(Sin B) = VA/VB

74. Snell's law is used to calculate:

Correct : C. Angle of refraction

75. Calculate the refracted shear wave angle in steel [VS = 0.323cm/microsec] for an incident longitudinal wave of 37.9 degrees in Plexiglas [VL = 0.267cm/microsec]

Correct : B. 45 degrees

76. Calculate the refracted shear wave angle in steel [VS = 0.323cm/microsec] for an incident longitudinal wave of 45.7 degrees in Plexiglas [VL = 0.267cm/microsec]

Correct : C. 60 degrees

77. Calculate the refracted shear wave angle in aluminium [VS = 0.31cm/microsec] for an incident longitudinal wave of 43.5 degrees in Plexiglas [VL =0.267cm/microsec]

Correct : A. 53 degrees

78. Calculate the refracted shear wave angle in aluminium [VS = 0.31cm/microsec] for an incident longitudinal wave of 53 degrees in Plexiglas [VL = 0.267cm/microsec]

Correct : D. 68 degrees

79. Lithium sulphate, barium titanate and lead metaniobate are examples of:

Correct : B. Piezoelectric elements

80. The particle motion for compression waves is:

Correct : A. Parallel to wave propagation

81. Shear waves for ultrasonic testing are usually produced:

Correct : B. Y cut crystals

82. Near surface resolution can be improved by:

Correct : B. Using a focused transducer

83. The most important requirement for paintbrush transducer is:

Correct : A. Uniform beam intensity across the transducer

84. Which of the following is an advantage of a focused transducer?

Correct : D. Higher resolution over a limited range

85. Which of the following is intended to be a ‘first cut’ or rough inspection device to be followed by more precise evaluation of any discontinuities found?

Correct : C. Paintbrush transducer

86. A wider entry surface indication or pulse may result from:

Correct : A. Side lobes of the sound beam being reflected from a rough surface

87. Which of the following methods might be used to reduce attenuation losses in an ultrasonic test?

Correct : B. Use a lower frequency transducer

88. When comparing discontinuity echoes to equivalent flat bottom hole echoes in materials with similar impedance, surface finish and attenuation:

Correct : D. None of the above

89. An advantage of immersion testing is that:

Correct : C. High test frequencies may be used

90. An advantage of immersion testing is that:

Correct : D. Irregularly shaped test pieces can be virtually completely examined

91. An ultrasonic data display which shows a plan view presentation of the data is called:

Correct : C. C scan

92. An ultrasonic display which shows a cross section of the test piece and any flaws which are found are called:

Correct : B. B scan

93. An ultrasonic display which shows echo locations and amplitude is called:

Correct : A. A scan

94. An advantage of using lower frequencies during ultrasonic testing is that:

Correct : D. Sensitivity to unfavourable oriented flaws is improved

95. A method of compensating for the ‘dead zone’ or near surface resolution problems is to:

Correct : B. Re-inspect from the opposite side of the test piece if geometry permits

96. When testing a test piece with parallel front and back surfaces, no back wall echo can be obtained. Which of the following actions might enable you to obtain a back wall echo?

Correct : B. Use a lower frequency transducer

97. Materials which can readily be inspected with frequencies of 1 to 5 MHz are:

Correct : C. Magnesium, titanium and steel

98. When variations are noticed in the front surface reflection, the test piece should be inspected for possible near surface discontinuities by:

Correct : C. Inspecting from the opposite side

99. Forging bursts are most often orientated:

Correct : C. In a random manner

100. The purpose of adding a wetting agent to an immersion bath is:

Correct : C. To eliminate air bubbles in the bath