UT Level I Review Questions

Question 1

1. The indication on the instrument display that
   represents the far boundary of the material being
   tested is called:

a. grass or hash.
b. the initial pause.
c. the main bang.
d. the back-surface reflection.

Answer 1

d. the back-surface reflection.

Question 2

2. In immersion testing, the position of the transducer
   is often varied by a manipulator to transmit sound
   into the test part at various angles to the front
   surface. Such a procedure is referred to as:

a. angulation.
b. dispersion.
c. reflection testing.
d. refraction.

Answer 2

a. angulation.

Question 3

3. The technical name for the cable that connects the
   ultrasonic instrument to the transducer is:

a. BX cable.
b. conduit.
c. coaxial cable.
d. ultrasonic conductor cable-grade 20.

Answer 3

c. coaxial cable.

Question 4

4. The process of standardizing an instrument or device
   by using a reference standard is called:

a. angulation.
b. calibration.
c. attenuation.
d. correlation.

Answer 4

b. calibration.

Question 5

5. Another name for a compressional wave is:

a. lamb wave.
b. shear wave.
c. longitudinal wave.
d. transverse wave

Answer 5

c. longitudinal wave.

Question 6

6. Another name for rayleigh waves is:

a. shear waves.
b. longitudinal waves.
c. transverse waves.
d. surface waves.

Answer 6

d. surface waves.

Question 7

7. A material used between the face of a transducer
   and the test surface to permit or improve the
   transmission of ultrasonic vibrations from the transducer to the material being tested is called:

a. a wetting agent.
b. a couplant.
c. an acoustic transmitter.
d. a lubricant.

Answer 7

b. a couplant.

Question 8

8. The piezoelectric material in a transducer that vibrates to produce ultrasonic waves is called a:

a. backing material.
b. plastic wedge.
c. crystal.
d. couplant.

Answer 8

c. crystal.

Question 9

9. Ultrasonic testing of material where the probe is in direct contact with the material being tested may be:

a. water jet.
b. immersion testing.
c. air coupled.
d. straight beam testing

Answer 9

d. straight beam testing

Question 10

10. An advantage of using lithium sulfate in transducers
    is that it:

a. is one of the most efficient generators of
ultrasonic energy.
b. is one of the most efficient receivers of
ultrasonic energy.
c. is insoluble.
d. can withstand temperatures as high as
700 °C (1260 °F).

Answer 10

b. is one of the most efficient receivers of
ultrasonic energy.

Question 11

11. The transducer shown in Figure 1 is used for:

a. surface wave testing.
b. angle beam testing.
c. immersion testing.
d. straight beam testing.

Answer 11

d. straight beam testing

Question 12

12. The transducer that contains the thinnest
    piezoelectric crystal is a:

a. 1 MHz transducer.
b. 5 MHz transducer.
c. 15 MHz transducer.
d. 25 MHz transducer.

Answer 12

d. 25 MHz transducer.

Question 13

13. Penetration of ultrasonic waves in a material is
    normally the function of test frequency used. The greatest depth of penetration is provided by a frequency of:
    a. 1 MHz
    b. 2.25 MHz
    c. 5 MHz
    d. 10 MHz

Answer 13

a. 1 MHz

Question 14

14. The amount of beam divergence from a crystal is primarily dependent on the:

a. type of test.
b. tightness of crystal backing in the transducer.
c. frequency and crystal size.
d. pulse length.

Answer 14

c. frequency and crystal size.

Question 15

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

a. attenuation.
b. rarefaction.
c. compression.
d. refraction

Answer 15

d. refraction

Question 16

16. Figure 2 illustrates a contact test on a 203 mm
    (8 in.) aluminum block. A discontinuity is located
    152 mm (6 in.) from the front surface. The display representation for this is shown to the right. What does indication A represent?

a. The initial pulse or front-surface indication.
b. The first discontinuity indication.
c. The first back-surface reflection.
d. Baseline

Answer 16

a. The initial pulse or front-surface indication.

Question 17

17. In Figure 2, indication B represents:

a. the initial pulse or front-surface indication.
b. the first discontinuity indication.
c. the first back-surface reflection.
d. baseline

Answer 17

b. the first discontinuity

Question 18

18. In Figure 2, indication C represents the:

a. second back-surface reflection.
b. first discontinuity indication.
c. second indication of the discontinuity.
d. first back-surface reflection.

Answer 18

d. first back-surface reflection.

Question 19

19. In Figure 2, indication D represents the:

a. first discontinuity indication.
b. second indication of the discontinuity.
c. first back-surface reflection.
d. second back-surface reflection

Answer 19

b. second indication of the discontinuity.

Question 20

20. In Figure 2, indication E represents the:

a. first discontinuity indication.
b. second indication of the discontinuity.
c. first back-surface reflection.
d. second back-surface reflection.

Answer 20

d. second back-surface reflection.

Question 21

21. The velocity of longitudinal waves is approximately
    ______ the velocity of shear waves in the same material.

a. two times
b. four times
c. 1/2
d. 9/10

Answer 21

a. two times

Question 22

22. Figure 3 illustrates an immersion test of a 76 mm (3 in.) block of aluminum with a discontinuity located 51 mm (2 in.) below the surface. The display
    pattern is shown also. What does indication A
    represent? Assume no sweep delay is used.

a. The first front-surface indication.
b. The initial pulse.
c. The first discontinuity indication.
d. The first back-surface reflection.

Answer 22

b. The initial pulse.

Question 23

23. In Figure 3, indication B represents the:

a. first front-surface indication.
b. initial pulse.
c. first back-surface reflection.
d. first discontinuity reflection.

Answer 23

a. first front-surface indication.

Question 24

24. In Figure 3, indication C represents the:

a. first front-surface indication.
b. first discontinuity indication.
c. first back-surface reflection.
d. second front-surface indication.

Answer 24

b. first discontinuity indication.

Question 25

25. In Figure 3, indication D represents the:

a. first discontinuity indication.
b. first back-surface reflection.
c. second front-surface indication.
d. second discontinuity indication.

Answer 25

b. first back-surface reflection.

Question 26

26. In Figure 3, the distance between indications A and B
    represents the:

a. distance from the front surface of the aluminum
block to the discontinuity.
b. distance from the front surface of the aluminum
block to the back surface of the aluminum block.
c. water distance from the transducer to the
aluminum block.
d. 76 mm.

Answer 26

c. water distance from the transducer to the
aluminum block.

Question 27

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

a. 1 MHz
b. 5 MHz
c. 10 MHz
d. 25 MHz

Answer 27

d. 25 MHz

Question 28

28. Which of the following materials of the same alloy is
    most likely to produce the greatest amount of sound attenuation over a given distance?

a. A hand forging.
b. A coarse-grained casting.
c. An extrusion.
d. The attenuation is equal in all materials.

Answer 28

b. A coarse-grained casting.

Question 29

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

a. initial pulse.
b. back reflection.
c. skip distance.
d. scan path.

Answer 29

a. initial pulse.

Question 30

30. An ultrasonic instrument display pattern containing
    a large number of low-level indications (often
    referred to as grass or hash) could be caused by:

a. a crack.
b. a large inclusion.
c. coarse-grained material.
d. a gas pocket.

Answer 30

c. coarse-grained material.

Question 31

31. A test method employing two separate transducers on opposite surfaces of the material being tested is
    called:

a. contact testing.
b. surface wave testing.
c. through-transmission testing.
d. lamb wave testing.

Answer 31

c. through-transmission testing.

Question 32

32. The number of complete waves that pass a given
    point in a given period of time (usually 1 s) is
    referred to as the:

a. amplitude.
b. pulse length.
c. frequency.
d. wavelength.

Answer 32

c. frequency.

Question 33

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

a. a rarefactor.
b. a refractor.
c. an interface.
d. a marker.

Answer 33

c. an interface.

Question 34

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

a. longitudinal wave.
b. shear wave.
c. surface wave.
d. lamb wave.

Answer 34

a. longitudinal wave.

Question 35

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

a. longitudinal wave.
b. shear wave.
c. surface wave.
d. lamb wave.

Answer 35

b. shear wave.

Question 36

36. The number “25 million cycles per second” can also
    be stated as:

a. 25 kHz.
b. 2500 kHz.
c. 25 MHz.
d. 25 μHz.

Answer 36

c. 25 MHz.

Question 37

37. Moving a transducer over a test surface either
    manually or automatically is referred to as:

a. scanning.
b. attenuating.
c. angulating.
d. resonating.

Answer 37

a. scanning.

Question 38

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

a. frequency.
b. velocity.
c. wavelength.
d. pulse length.

Answer 38

b. velocity.

Question 39

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

a. distance amplitude height.
b. absorption level.
c. vertical limit.
d. limit of resolution.

Answer 39

c. vertical limit.

Question 40

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

a. angle beam testing.
b. immersion testing.
c. contact testing.
d. through-transmission testing.

Answer 40

a. angle beam testing.

Question 41

41. In Figure 4, angle 1 (θ1) is called the angle of:

a. incidence.
b. reflection.
c. refraction.
d. diffraction.

Answer 41

a. incidence.

Question 42

42. In Figure 4, angle 2 (θ2) is called the angle of:

a. incidence.
b. reflection.
c. refraction.
d. diffraction.

Answer 42

b. reflection.

Question 43

43. In Figure 4, angle 3 (θ3) is called the angle of:

a. incidence.
b. reflection.
c. refraction.
d. rarefaction.

Answer 43

c. refraction.

Question 44

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

a. 1 and 25 kHz.
b. 1 and 1000 kHz.
c. 0.2 and 25 MHz.
d. 15 and 100 MHz.

Answer 44

c. 0.2 and 25 MHz.

Question 45

45. In an A-scan presentation, the horizontal baseline
    represents the:

a. amount of reflected ultrasonic sound energy.
b. distance travelled by the transducer.
c. elapsed time or distance.
d. signal amplitude.

Answer 45

c. elapsed time or distance.

Question 46

46. In an A-scan presentation, the amplitude of vertical
    indications on the display represents the:

a. amount of ultrasonic sound energy returning to the transducer.
b. distance travelled by the transducer.
c. thickness of material being tested.
d. elapsed time since the ultrasonic pulse was
generated.

Answer 46

a. amount of ultrasonic sound energy returning to the transducer.

Question 47

47. Which of the following test frequencies would
    generally provide the best penetration in a 305 mm (12 in.) thick specimen of coarse-grained steel?

a. 1 MHz
b. 2.25 MHz
c. 5 MHz
d. 10 MHz

Answer 47

a. 1 MHz

Question 48

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

a. the high indication on the extreme left side of the
display that represents the entry surface of the
inspected part.
b. the first pulse that occurs near the right side of
the display and represents the opposite boundary
of the inspected part.
c. an indication that appears and disappears during
screening.
d. always the second pulse from the left on the
viewing display.

Answer 48

a. the high indication on the extreme left side of the
display that represents the entry surface of the
inspected part.

Question 49

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

a. laminar-type discontinuities with major
dimensions parallel to the rolled surface.
b. transverse-type discontinuities with major
dimensions at right angles to the rolled surface.
c. radial discontinuities with major dimensions
along length but radially oriented to the rolled
surface.
d. rounded discontinuities such as porosity.

Answer 49

a. laminar-type discontinuities with major
dimensions parallel to the rolled surface.

Question 50

50. In ultrasonic testing, a liquid coupling medium between the crystal surface and the part surface is necessary because:

a. lubricant is required to minimize wear on the
crystal surface.
b. an air interface between the crystal surface and
the part surface would almost completely reflect
the ultrasonic vibrations.
c. the crystal will not vibrate if placed directly in
contact with the surface of the part being
inspected.
d. the liquid is necessary to complete the electrical
circuit in the transducer.

Answer 50

b. an air interface between the crystal surface and
the part surface would almost completely reflect
the ultrasonic vibrations.

Question 51

51. Near-surface resolution is a characteristic of an
    ultrasonic testing system that defines its ability to detect:

a. discontinuities oriented in a direction parallel to
the ultrasonic beam.
b. discontinuities located in the center of a forging
containing a fine metallurgic structure.
c. minute surface scratches.
d. discontinuities located just beneath the
entry-surface in the part being tested.

Answer 51

d. discontinuities located just beneath the
entry-surface in the part being tested.

Question 52

52. During ultrasonic testing by the immersion method,
    it is frequently necessary to angulate the transducer
    when a discontinuity is located in order to:

a. avoid a large number of back reflections that
could interfere with a normal test pattern.
b. obtain a maximum response if the discontinuity is
not originally oriented perpendicular to the
ultrasonic beam.
c. obtain the maximum number of entry surface
reflections.
d. obtain a discontinuity indication of the same
height as the indication from the flat-bottom hole
in a reference block.

Answer 52

b. obtain a maximum response if the discontinuity is
not originally oriented perpendicular to the
ultrasonic beam.

Question 53

53. All other factors being equal, the mode of vibration
    that has the greatest velocity is the:

a. shear wave.
b. transverse wave.
c. surface wave.
d. longitudinal wave.

Answer 53

d. longitudinal wave.

Question 54

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

a. all of the same diameter.
b. different in diameter, increasing by 0.4 mm
(0.016 in.) increments from the No. 1 block to the
No. 8 block.
c. largest in the No. 1 block and smallest in the
No. 8 block.
d. drilled to different depths from the front surface
of the test block.

Answer 54

b. different in diameter, increasing by 0.4 mm
(0.016 in.) increments from the No. 1 block to the
No. 8 block.

Question 55

55. In immersion testing, verification that the transducer
    is normal to a flat entry surface is indicated by:

a. maximum reflection from the entry surface.
b. elimination of water multiples.
c. proper wavelength.
d. maximum amplitude of the initial pulse.

Answer 55

a. maximum reflection from the entry surface.

Question 56

56. A piezoelectric material can:

a. convert a longitudinal beam to a shear wave.
b. convert a mechanical energy to electrical energy.
c. create ionization in a test specimen.
d. produce sound waves in a coaxial cable.

Answer 56

b. convert a mechanical energy to electrical energy.

Question 57

57. Sound waves of a frequency beyond the hearing range of the human ear are referred to as ultrasonic waves or vibrations, and the term embraces all
    vibrational waves of frequency greater than
    approximately:

a. 2 kHz
b. 200 kHz
c. 20 000 Hz
d. 2 MHz

Answer 57

c. 20 000 Hz

Question 58

58. The velocity of sound waves is primarily dependent
    on the:

a. pulse length.
b. angle of incidence.
c. material properties and wave type.
d. frequency.

Answer 58

c. material properties and wave type.

Question 59

59. The primary purpose of reference blocks is to:

a. aid the operator in obtaining maximum back
reflections.
b. obtain the greatest sensitivity possible from an
instrument.
c. obtain a common reproducible signal.
d. properly tune the transducer

Answer 59

c. obtain a common reproducible signal.

Question 60

60. When testing by the surface wave method, patches of oil or dirt on the surface may:

a. block the progress of all sound.
b. attenuate the sound.
c. have no effect on the test.
d. cause both an attenuation of sound and
indications on the screen.

Answer 60

d. cause both an attenuation of sound and
indications on the screen.

Question 61

61. In immersion testing, the most commonly used
    couplant is:

a. water.
b. oil.
c. glycerine.
d. alcohol.

Answer 61

a. water.

Question 62

62. The piezoelectric material in the transducer:

a. converts electrical energy into sound.
b. converts electrical energy into mechanical energy
and mechanical energy into electrical energy.
c. eliminates the signal-to-noise energy.
d. produces high-speed electrons in metals.

Answer 62

b. converts electrical energy into mechanical energy

Question 63

63. The shortest wavelength pulse is produced by a
    frequency of:

a. 1 MHz
b. 5 MHz
c. 10 MHz
d. 25 MHz

Answer 63

d. 25 MHz

Question 64

64. The angle of incidence is:

a. greater than the angle of reflection.
b. less than the angle of reflection.
c. equal to the angle of reflection.
d. not related to the angle of reflection.

Answer 64

c. equal to the angle of reflection.

Question 65

65. On many ultrasonic testing instruments, an operator conducting an immersion test can remove that portion of the display presentation that represents water distance by adjusting a:

a. pulse length control.
b. reject control.
c. sweep delay control.
d. sweep length control.

Answer 65

c. sweep delay control.

Question 66

66. What is another way to express 100 000 cycles per second ?

a. 0.1 kHz
b. 10 kHz
c. 100 kHz
d. 100 MHz

Answer 66

c. 100 kHz

Question 67

67. Figure 5 is an illustration of a typical:

a. A-scan presentation.
b. B-scan presentation.
c. C-scan presentation.
d. D-scan presentation.

Answer 67

a. A-scan presentation.

Question 68

68. Figure 6 is an illustration of a typical:

a. A-scan presentation.
b. B-scan presentation.
c. C-scan presentation.
d. D-scan presentation.

Answer 68

c. C-scan presentation.

Question 69

69. Figure 7 is an illustration of a typical:

a. A-scan presentation.
b. B-scan presentation.
c. C-scan presentation.
d. D-scan presentation.

Answer 69

b. B-scan presentation.

Question 70

70. A transducer with a frequency greater than 10 MHz will most likely be used during:

a. a straight beam contact test of aluminum ingot.
b. an angle beam contact test of a steel pipe.
c. a surface wave contact test of a metallic plate.
d. an immersion test.

Answer 70

d. an immersion test.

Question 71

71. The reference holes in standard aluminum
    area-amplitude ultrasonic test blocks contain:

a. flat-bottom holes.
b. concave-surface holes.
c. convex-surface holes.
d. conical-shaped holes.

Answer 71

a. flat-bottom holes.

Question 72

72. The gradual loss of sonic energy as the ultrasonic vibrations travel through the material is referred to
    as:

a. reflection.
b. refraction.
c. reproducibility.
d. attenuation.

Answer 72

d. attenuation.

Question 73

73. A term used to describe numerous small indications
    on the instrument display resulting from test part structure, numerous small discontinuities, or both is often referred to as:

a. multiple back reflections.
b. multiple front reflections.
c. grass or hash.
d. resonance.

Answer 73

c. grass or hash.

Question 74

74. When testing a plate, increasing the frequency of an
    ultrasonic longitudinal wave results in:

a. an increase in its velocity.
b. a decrease in its velocity.
c. no change in its velocity.
d. a reversal in its velocity.

Answer 74

c. no change in its velocity.

Question 75

75. Ultrasonic waves transmitted into and received from the test material in the form of repetitive bursts of acoustic energy is called:

a. pulse echo testing.
b. continuous wave testing.
c. resonance testing.
d. through-transmission testing

Answer 75

a. pulse echo testing.

Question 76

76. Metal blocks, which contain one or more drilled holes or notches to simulate
    discontinuities, are called:
    a. scrubbers.
    b. crystal collimators.
    c. single-plane angulators.
    d. reference blocks.

Answer 76

d. reference blocks.

Question 77

77. If the major dimensions of a discontinuity in a
    152 mm (6 in.) thick aluminum plate lie parallel to the entry surface at a depth of 76 mm (3 in.), it will be best detected by:

a. a straight beam test.
b. an angle beam test.
c. a surface wave test.
d. a lamb wave test.

Answer 77

a. a straight beam test.

Question 78

78. The presence of a discontinuity will not produce a specific discontinuity indication on the ultrasonic
    instrument display when using the:

a. straight beam testing method.
b. surface wave testing method.
c. angle beam testing method.
d. through-transmission testing method.

Answer 78

d. through-transmission testing method.

Question 79

79. The depth of a discontinuity cannot be determined when using the:

a. straight beam testing method.
b. through-transmission testing method.
c. angle beam testing method.
d. immersion testing method.

Answer 79

b. through-transmission testing method.

Question 80

80. When inspecting coarse-grained material, a sound wave is most easily scattered by the grain structure by
    a frequency of:

a. 1 MHz
b. 2.25 MHz
c. 5 MHz
d. 10 MHz

Answer 80

d. 10 MHz

Question 81

81. The thickest crystal is contained in a:

a. 1 MHz transducer.
b. 5 MHz transducer.
c. 15 MHz transducer.
d. 25 MHz transducer.

Answer 81

a. 1 MHz transducer.

Question 82

82. When performing a surface wave test, indications may result from:

a. improper frequency.
b. oil on the surface.
c. a surface discontinuity.
d. the acoustical velocity of aluminum.

Answer 82

c. a surface discontinuity.

Question 83

83. Which of the following discontinuities located 152
    mm (6 in.) from the entry surface results in the largest display indication if all factors except discontinuity surface condition and orientation are the same?

a. 2 mm (0.08 in.) diameter flat-surfaced
discontinuity whose major face is at an angle of
75° from the direction of sound beam
propagation.
b. 2 mm (0.08 in.) diameter rough-surfaced
discontinuity whose major face is at an angle of
75° from the direction of sound beam
propagation.
c. 2 mm (0.08 in.) diameter flat-surfaced
discontinuity whose major face is perpendicular
to the direction of sound beam propagation.
d. 2 mm (0.08 in.) diameter rough-surfaced
discontinuity whose major face is parallel to the
direction of sound beam propagation.

Answer 83

c. 2 mm (0.08 in.) diameter flat-surfaced
discontinuity whose major face is perpendicular
to the direction of sound beam propagation.

Question 84

84. Transducers constructed with a plastic wedge or
    standoff between the transducer element and the test piece are commonly used:

a. for angle beam contact testing.
b. for immersion testing.
c. to eliminate the need for a couplant.
d. to reduce the speed of electrons.

Answer 84

a. for angle beam contact testing.

Question 85

85. Sound can be focused by special curved adapters
    located in front of the transducer element. These adapters are referred to as:

a. scrubbers.
b. acoustic lenses.
c. angle beam adapters.
d. single plane adapters.

Answer 85

b. acoustic lenses.

Question 86

86. A test method in which the parts to be inspected are
    placed in a water bath or some other liquid couplant is called:

a. contact testing.
b. immersion testing.
c. surface wave testing.
d. through-transmission testing.

Answer 86

b. immersion testing.

Question 87

87. A separate time baseline imposed on the viewing
    display of some ultrasonic testing instruments that
    permits measurement of distances is often referred to as:

a. an initial pulse.
b. a time/distance line.
c. an electronic gate.
d. a sweep line.

Answer 87

c. an electronic gate.

Question 88

88. A term used to describe the ability of an ultrasonic
    testing system to distinguish between the
    entry-surface response and the response of
    discontinuities near the entry surface is:

a. sensitivity.
b. penetration.
c. segregation.
d. resolution.

Answer 88

d. resolution.

Question 89

89. The phenomenon whereby an ultrasonic wave changes direction when the wave crosses a boundary between materials with different velocities is called:

a. refraction.
b. reflection.
c. penetration.
d. rarefaction.

Answer 89

a. refraction.

Question 90

90. In a test where the transducer is not perpendicular
    to the inspection surface, the angle of incidence is
    equal to:

a. the angle of refraction.
b. the angle of reflection.
c. the shear wave angle.
d. half the shear wave angle.

Answer 90

b. the angle of reflection.

Question 91

91. The product of the acoustic velocity of sound in a
    material and the density of the material is the
    factor that determines the amount of reflection or transmission of ultrasonic energy when it reaches an
    interface. This is called:

a. acoustic impedance.
b. velocity.
c. wavelength.
d. penetration.

Answer 91

a. acoustic impedance.

Question 92

92. In transmitting energy into the part shown in
    Figure 8, the ultrasonic beam will:

a. diverge (spread out) through the part.
b. converge (focus in to a point) through the part.
c. transmit straight through the part.
d. not enter the part.

Answer 92

a. diverge (spread out) through the part.

Question 93

93. Ultrasonic waves that travel along the surface of a material and whose particle motion is elliptical are
    called:

a. shear waves.
b. transverse waves.
c. longitudinal waves.
d. rayleigh waves.

Answer 93

d. rayleigh waves.

Question 94

94. The interference field near the face of a transducer is often referred to as the:

a. fresnel zone.
b. acoustic impedance.
c. exponential field.
d. phasing zone.

Answer 94

a. fresnel zone.

Question 95

95. When the incident angle is chosen to be between the
    first and second critical angles, the ultrasonic wave mode within the part will be a:

a. longitudinal wave.
b. shear wave.
c. surface wave.
d. lamb wave.

Answer 95

b. shear wave.

Question 96

96. The formula used to calculate the angle of refraction within a material is called:

a. Fresnel’s law.
b. Fraunhofer’s law.
c. Snell’s law.
d. Lamb’s law.

Answer 96

c. Snell’s law.

Question 97

97. In a material with a given velocity, when frequency is
    increased, the wavelength will:

a. not be affected.
b. increase.
c. decrease.
d. double.

Answer 97

c. decrease.

Question 98

98. Circuits that electronically amplify return signals
    from the receiving transducer and often modify the signals into a form suitable for display are called:

a. pulser circuits.
b. marker circuits.
c. timer circuits.
d. receiver-amplifier circuits.

Answer 98

d. receiver-amplifier circuits.

Question 99

99. The most common type of data display used for ultrasonic examination of welds is:

a. an A-scan display.
b. a B-scan display.
c. a C-scan display.
d. an X-Y plot display.

Answer 99

a. an A-scan display.

Question 100

100. The display that plots signal amplitude versus time is called:

a. an A-scan display.
b. a B-scan display.
c. a C-scan display.
d. a D-scan display

Answer 100

a. an A-scan display.

Question 101

101. A circuit that modifies the return signal from the
     receiving transducer into a form suitable for display on an oscilloscope or other output device is called a:

a. pulser.
b. receiver-amplifier.
c. clock.
d. sweep.

Answer 101

b. receiver-amplifier.

Question 102

102. A circuit that generates a burst of voltage that is
     applied to the sending transducer is called:

a. a pulser.
b. a receiver-amplifier.
c. damping.
d. a clock.

Answer 102

a. a pulser.

Question 103

103. A circuit that coordinates electronic operation of the
     entire ultrasonic instrument system is called:

a. damping.
b. a receiver-amplifier.
c. a clock.
d. a power supply.

Answer 103

c. a clock.

Question 104

104. A plan view display or recording of a part under
     examination is called:

a. a C-scan display.
b. an A-scan display.
c. an X-axis plot.
d. a strip chart recording.

Answer 104

a. a C-scan display.

Question 105

105. Ultrasonic data, which is presented in a form representative of the cross section of the test specimen, is called:

a. an A-scan presentation.
b. a B-scan presentation.
c. a C-scan presentation.
d. an X-Y plot.

Answer 105

b. a B-scan presentation.

Question 106

106. What type of ultrasonic examination uses wheel-type
     transducers that eliminate the use of a tank?

a. Through-transmission testing.
b. Contact testing.
c. Resonance testing.
d. Immersion testing.

Answer 106

d. Immersion testing.

Question 107

107. In addition to other functions, a transducer
     manipulator in a mechanical immersion-scanning unit permits:

a. use of the through-transmission technique.
b. use of high scanning speeds.
c. detection of obliquely oriented discontinuities.
d. utilization of less skilled operators.

Answer 107

c. detection of obliquely oriented discontinuities.

Question 108

108. A type of data presentation most likely to be used
     with a high-speed automatic scanning system is:

a. an A-scan presentation.
b. a velocity versus amplitude plot.
c. a C-scan presentation.
d. a plot of echo height versus depth.

Answer 108

c. a C-scan presentation.

Question 109

109. The component in a conventional immersion system
     that spans the width of the immersion tank is called:

a. an articulator.
b. a bridge.
c. a manipulator.
d. a search tube.

Answer 109

b. a bridge.

Question 110

110. The component in an ultrasonic immersion system that is used to adjust and maintain a known transducer angle is called:

a. a carriage.
b. a manipulator.
c. a search tube.
d. an index system.

Answer 110

b. a manipulator.

Question 111

111. An amplitude type gate is necessary for all:

a. shear wave examinations.
b. longitudinal wave examinations.
c. automatic examinations.
d. manual examinations.

Answer 111

c. automatic examinations.

Question 112

112. When a C-scan recording is used to produce a permanent record of an ultrasonic test, the information displayed is typically the discontinuity’s:

a. depth and size.
b. depth, orientation, and size.
c. location and depth.
d. location and size (plan view).

Answer 112

d. location and size (plan view).

Question 113

113. Rough entry surface conditions can result in:

a. an increase in echo amplitude from discontinuities.
b. a decrease in the width of the front-surface echo.
c. a loss of amplitude from discontinuities.
d. a loss of material velocity.

Answer 113

c. a loss of amplitude from discontinuities.

Question 114

114. As the grain size increases in a material, its principal
     effect in ultrasonic testing is on the:

a. velocity of sound.
b. attenuation.
c. acoustic impedance.
d. angle of refraction.

Answer 114

b. attenuation.

Question 115

115. In straight beam pulse echo testing, a discontinuity with a rough reflecting surface perpendicular to the incident wave has what effect on the detected signal in comparison to a smooth flat-bottom hole of the same size?

a. It increases the detected signal.
b. It decreases the detected signal.
c. It has no effect on the detected signal.
d. It decreases the width of the pulse of the detected
signal.

Answer 115

b. It decreases the detected signal.

Question 116

116. Which material can only transmit longitudinal waves?

a. Machine oil.
b. Aluminum.
c. Ice.
d. Beryllium.

Answer 116

a. Machine oil.

Question 117

117. If the velocity of a longitudinal mode wave in a given homogeneous material is 0.625 cm/μs at 13 mm
     (0.5 in.) below the surface, what is the velocity at
     51 mm (2 in.) below the surface?

a. One-fourth the velocity at 13 mm (0.5 in.).
b. One-half the velocity at 13 mm (0.5 in.).
c. The same as the velocity at 13 mm (0.5 in.).
d. Three-fourths the velocity at 13 mm (0.5 in.)

Answer 117

c. The same as the velocity at 13 mm (0.5 in.).

Question 118

118. What effect will replacing a 2.25 MHz transducer with a 5 MHz transducer have on the wavelength?

a. Make it longer.
b. Have no effect.
c. Make it shorter.
d. Increase it and the acoustic impedance.

Answer 118

c. Make it shorter.

Question 119

119. What can cause nonrelevant indications on the A-scan display?

a. Rectangular-shaped test specimens.
b. Setting a low pulse repetition rate.
c. Small grain structure of test specimens.
d. Edge effects.

Answer 119

d. Edge effects.

Question 120

120. The proper interpretation and evaluation of the
     presented discontinuity signals are essential to any nondestructive test. A common method for the estimation of discontinuity size is the use of:

a. a double transducer test.
b. a piezoelectric standard.
c. mode conversion.
d. a reference standard.

Answer 120

d. a reference standard.

Question 121

121. Another name for fresnel zone is:

a. zone.
b. near field.
c. far field.
d. torrid zone.

Answer 121

b. near field.

Question 122

122. Attenuation is a:

a. test display characteristic.
b. test material parameter.
c. transducer characteristic.
d. form of testing.

Answer 122

b. test material parameter.

Question 123

123. For discontinuity geometries other than flat, the echo
     amplitude is usually _________ from that observed for a flat discontinuity, of similar orientation perpendicular to the sound beam.

a. identical
b. increased
c. decreased
d. elongated

Answer 123

c. decreased

Question 124

124. To evaluate discontinuities that are oriented at an
     angle to the entry surface so that the sound beam
     strikes the plane of the discontinuity at right angles, the operator must:

a. change the frequency.
b. grind the surface.
c. angulate the transducer.
d. increase the gain.

Answer 124

c. angulate the transducer.

Question 125

125. The pulser circuit in an ultrasonic instrument is used
     to:

a. control the horizontal and vertical sweep.
b. activate the transducer.
c. control transducer timing between transmit and
sweep.
d. generate markers that appear on horizontal
sweep.

Answer 125

b. activate the transducer.

Question 126

126. An A-scan display, which shows a signal both above and below the sweep line, is called:

a. a video display.
b. an RF display.
c. an audio display.
d. a frequency modulated display.

Answer 126

b. an RF display.

Question 127

127. A B-scan display shows the relative:

a. distance a discontinuity is from the transducer
and its through-dimension thickness.
b. distance a discontinuity is from the transducer
and its length in the direction of transducer
travel.
c. cross-sectional area of a discontinuity above a
predetermined amplitude.
d. pulse height and time of arrival to produce a
plan-view image.

Answer 127

b. distance a discontinuity is from the transducer
and its length in the direction of transducer
travel.

Question 128

128. Surface (rayleigh) waves traveling on the top face of a
     block:

a. are not reflected from a sharp edge corner.
b. are reflected from a sharp edge corner.
c. travel through the sharp edge corner and are
reflected from the lower edge.
d. are absorbed by a sharp edge corner.

Answer 128

b. are reflected from a sharp edge corner.

Question 129

129. Surface (rayleigh) waves are more highly attenuated by a:

a. curved surface.
b. heavy couplant.
c. thin couplant.
d. sharp corner.

Answer 129

b. heavy couplant.

Question 130

130. The velocity of sound in a material is dependent upon the:

a. frequency of the wave.
b. wavelength.
c. material properties.
d. vibration cycle.

Answer 130

c. material properties.

Question 131

131. To vary or change the wavelength of sound being
     used to test a part, change the:

a. sound wave frequency.
b. diameter of the transducer.
c. electrical pulse voltage.
d. pulse repetition rate.

Answer 131

a. sound wave frequency.

Question 132

132. Ultrasonic vibrations are commonly used to:

a. support findings after visual inspection.
b. characterize grain structure.
c. detect discontinuities in multilayered structures
having air gaps between layers.
d. perform volumetric examinations of ferrous and
nonferrous materials.

Answer 132

d. perform volumetric examinations of ferrous and
nonferrous materials.

Question 133

133. Which of the following has the longest fresnel zone?

a. 13 mm (0.5 in.) diameter 1 MHz.
b. 13 mm (0.5 in.) diameter 2.25 MHz.
c. 28.5 mm (1.125 in.) diameter 1 MHz.
d. 38 mm (1.5 in.) diameter 2 MHz.

Answer 133

d. 38 mm (1.5 in.) diameter 2 MHz.

Question 134

134 When contact testing, if the ultrasonic instrument is set with an excessively high pulse repetition
frequency:

a. the screen trace becomes too light to see.
b. the time-baseline becomes distorted.
c. the initial pulse disappears.
d. UT Signals may overlap with the multiples of the backwall echoes.

Answer 134

d. UT Signals may overlap with the multiples of the backwall echoes.

Question 135

135. The advantages of immersion testing include:

a. portability.
b. reduced equipment needed.
c. low equipment and maintenance costs.
d. adaptability for automated scanning.

Answer 135

d. adaptability for automated scanning.

Question 136

136. Longitudinal wave velocity in water is approximately one-fourth the velocity in aluminum or steel.
     Therefore, the minimum water path should be:

a. four times the test piece thickness.
b. one-half the test piece thickness.
c. one-fourth the test piece thickness plus 6 mm
(0.25 in.).
d. one-half the test piece thickness plus 6 mm
(0.25 in.)

Answer 136

c. one-fourth the test piece thickness plus 6 mm
(0.25 in.).

Question 137

137. In immersion testing, a wetting agent is added to the
     water to:

a. adjust the viscosity.
b. help eliminate the formation of air bubbles.
c. prevent cloudiness.
d. aid in technician comfort.

Answer 137

b. help eliminate the formation of air bubbles.

Question 138

138. The formula used to determine the fundamental
     resonant frequency is:

a. F = V/T .
b. F = V /2T .
c. F = T/V .
d. F = VT .

Answer 138

b. F = V /2T .

Question 139

139. If frequency is increased, wavelength:

a. decreases (becomes shorter).
b. increases (becomes longer).
c. remains the same but velocity increases.
d. remains the same but velocity decreases.

Answer 139

a. decreases (becomes shorter).

Question 140

140. The variable in distance amplitude calibration block
     construction is the:

a. drilled hole size.
b. drilled hole point angle.
c. metal distance above the drilled hole.
d. angle of the drilled hole to block longitudinal
axis.

Answer 140

c. metal distance above the drilled hole.

Question 141

141. When setting up a distance amplitude correction curve using three flat-bottom holes, sometimes the
     hole closest to the transducer gives less of a response than one or both of the other two. This could be caused by:

a. a hole that is too large.
b. near field effects.
c. impedance mismatch.
d. the acoustic velocity.

Answer 141

b. near field effects.

Question 142

142. Ferrous and nonferrous welds may be ultrasonically
     tested using a frequency range of:

a. 25-100 kHz
b. 200-500 kHz
c. 2-5 MHz
d. 3-6 MHz

Answer 142

c. 2-5 MHz

Question 143

143. The product of the material density and the velocity of sound within that material is referred to as:

a. acoustic impedance.
b. near field.
c. acoustic attenuation.
d. ultrasonic beam distribution.

Answer 143

a. acoustic impedance.

Question 144

144. A straight beam contact transducer consists of:

a. a case, a crystal, wear plate, and backing.
b. a case, a crystal, backing, and a plastic wedge.
c. a case, a crystal, backing, and acoustic lenses.
d. a case, a crystal, a mount, backing, a plastic
wedge, and acoustic lenses.

Answer 144

a. a case, a crystal, wear plate, and backing.

Question 145

145. In immersion testing, to remove the second water
     reflection from between the entry surface signal and the first back reflection, you should:

a. increase the repetition rate.
b. decrease the frequency.
c. decrease the sweep length.
d. increase the water path.

Answer 145

d. increase the water path.

Question 146

146. For a given incident angle, as the frequency of the transducer increases, the refracted angle:

a. increases.
b. decreases.
c. stays the same.
d. cannot be determined.

Answer 146

c. stays the same.

Question 147

147. Both longitudinal and shear waves may be simultaneously generated in a second medium when
     the angle of incidence is:

a. between normal and the first critical angle.
b. between the first and second critical angles.
c. past the second critical angle.
d. only at the second critical angle.

Answer 147

a. between normal and the first critical angle.

Question 148

148. Penetration of ultrasonic waves in a material is
     normally the function of test frequency used. The greatest depth of penetration is provided by a frequency of:

a. 1 MHz
b. 2.25 MHz
c. 5 MHz
d. 10 MHz

Answer 148

a. 1 MHz

Question 149

149. Refracted energy assumes a new direction of
     propagation when the _________ is changed.

a. principal angle
b. reflected angle
c. critical angle
d. incident angle

Answer 149

d. incident angle

Question 150

150. The loss of energy as it propagates through material
     is the result of beam:

a. interference.
b. attenuation.
c. absorption.
d. reflection.

Answer 150

b. attenuation.

Question 151

151. In selecting a suitable couplant, which of the following characteristics would not affect the selection?

a. Mode of propagation desired.
b. Material surface finish and temperature.
c. Operating frequency of the transducer.
d. Chemical properties of the couplant.

Answer 151

c. Operating frequency of the transducer.

Question 152

152. Excessive surface roughness of the material being
     tested can cause:

a. a loss of echo amplitude from discontinuities
within the material.
b. reduced acoustic velocity.
c. increased acoustic velocity.
d. increased back-surface response.

Answer 152

a. a loss of echo amplitude from discontinuities
within the material.

Question 153

153. Reference or calibration standards are used for:

a. determining phase shift analysis.
b. providing a method for standardizing the test system.
c. determining tensile strength.
d. measuring vibrations.

Answer 153

b. providing a method for standardizing the test system.

Question 154

154. The change in direction of an ultrasonic beam when
     it passes from one material to another material in which elasticity and density differ is called:

a. reflection.
b. rarefaction.
c. angulation.
d. refraction.

Answer 154

d. refraction.

Question 155

155. If a discontinuity is oriented at an angle other than 90° to the sound beam, the results may be a:

a. loss of signal linearity.
b. loss or lack of signal reflected from the
discontinuity.
c. focusing of the sound beam.
d. loss of interference phenomena.

Answer 155

b. loss or lack of signal reflected from the
discontinuity.

Question 156

156. A device that transforms electrical pulses into mechanical and vice versa utilizes:

a. Snell’s law.
b. piezoelectric principles.
c. mode conversion principles.
d. particle motion principles.

Answer 156

b. piezoelectric principles.

Question 157

157. Whenever an ultrasonic incident angle is set at 5°
     from normal in water:

a. the refracted wave is mode converted.
b. the refracted wave is the same mode as the
incident wave.
c. the refracted wave in steel has two components,
one of which will be the same mode as the
incident wave.
d. it is impossible to determine mode(s) of a
refracted wave without more information.

Answer 157

c. the refracted wave in steel has two components,
one of which will be the same mode as the
incident wave.

Question 158

158. If a discontinuity is located in the fresnel or near-field region of a sound beam:

a. the larger the discontinuity, the larger the amplitude of the reflected signal.
b. the closer to the surface the discontinuity is
located, the larger will be the amplitude of the
reflected signal.
c. in immersion testing, the amplitude of the signal
increases as the water path decreases.
d. in immersion testing, the amplitude of the
reflected signal may increase or decrease as the
water path decreases.

Answer 158

d. in immersion testing, the amplitude of the
reflected signal may increase or decrease as the
water path decreases.

Question 159

159. If a transducer is vibrating at a frequency and injecting ultrasonic energy through water into a steel specimen:

a. the sound wavelength is the same in both the
water and the steel.
b. the sound frequency in the water is less than the
sound frequency in steel.
c. the sound wavelength is not the same in both the
water and the steel.
d. the sound frequency in the water is greater than
the sound frequency in steel.

Answer 159

c. the sound wavelength is not the same in both the water and the steel.

Question 160

160. When a longitudinal sound wave strikes a water-steel interface at an angle of incidence of 15°(see Figure 9):

a. all the sound energy is reflected back into the
water at an angle of 15°.
b. part of the sound energy is reflected at 15° and
part is refracted into the steel at an angle of less
than 15°.
c. part of the sound energy is reflected at 15° and
part is refracted along the water-steel interface.
d. part of the sound energy is reflected at 15° and
part is refracted into the steel at an angle greater
than 15°

Answer 160

d. part of the sound energy is reflected at 15° and
part is refracted into the steel at an angle greater
than 15°