UTT

Question 1

1.The indication on the instrument display thatrepresents the far boundary of the material beingtested 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 transducersis that it:
    a.is one of the most efficient generators of ultrasonic energy.
    b.is one of the most efficient receivers ofultrasonic 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 ofultrasonic 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 afrequency 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 indication.

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 aluminumblock to the discontinuity.
b.distance from the front surface of the aluminumblock 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 followingfrequencies 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 iscalled:
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) isreferred 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 alsobe stated as:
a.25 kHz.
b.2500 kHz.
c.25 MHz.
d.25 uHz.

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 traveled 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 traveled by the transducer.
c.thickness of material being tested.
d.elapsed time since the ultrasonic pulse wasgenerated.

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 thedisplay that represents the entry surface of theinspected part.
b.the first pulse that occurs near the right side ofthe display and represents the opposite boundaryof the inspected part.
c.an indication that appears and disappears duringscreening.
d.always the second pulse from the left on theviewing 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 majo rdimensions 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 majo rdimensions 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 incontact 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 50

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 50

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

Question 50

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 50

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

Question 51

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 51

d.longitudinal wave.

Question 52

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 52

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

Question 53

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 53

a.maximum reflection from the entry surface.

Question 54

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 54

b.convert a mechanical energy to electrical energy.

Question 55

57.Sound waves of a frequency beyond the hearin grange 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 55

c.20 000 Hz

Question 56

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 56

c.material properties and wave type.

Question 57

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 57

c.obtain a common reproducible signal.

Question 58

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 58

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

Question 59

61.In immersion testing, the most commonly used couplant is:
a.water.
b.oil.
c.glycerine.
d.alcohol.

Answer 59

a.water.

Question 60

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 60

b.converts electrical energy into mechanical energy and mechanical energy into electrical energy.

Question 61

63.The shortest wavelength pulse is produced by a frequency of:
a.1 MHz
b.5 MHz
c.10 MHz
d.25 MHz

Answer 61

d.25 MHz

Question 62

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 62

c.equal to the angle of reflection.

Question 63

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 63

c.sweep delay control.

Question 64

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 64

c.100 kHz

Question 65

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 65

a.A-scan presentation.

Question 66

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 66

c.C-scan presentation.

Question 67

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 67

b.B-scan presentation.

Question 68

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 68

d.an immersion test.

Question 69

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 69

a.flat-bottom holes.

Question 70

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 70

d.attenuation.

Question 71

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 71

c.grass or hash.

Question 72

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 72

c.no change in its velocity.

Question 73

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 73

a.pulse echo testing.

Question 74

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 74

d.reference blocks.

Question 75

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 willbe best detected by:
a.a straight beam test.
b.an angle beam test.
c.a surface wave test.
d.a lamb wave test.

Answer 75

a.a straight beam test.

Question 76

78.The presence of a discontinuity will not produce aspecific 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 76

d.through-transmission testing method.

Question 77

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 77

b.through-transmission testing method.

Question 78

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 78

d.10 MHz

Question 79

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 79

a.1 MHz transducer.

Question 80

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 80

c.a surface discontinuity

Question 81

83.Which of the following discontinuities located 152mm (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 of75° from the direction of sound beampropagation.
b.2 mm (0.08 in.) diameter rough surfaced discontinuity whose major face is at an angle of75° from the direction of sound beampropagation.
c.2 mm (0.08 in.) diameter flat surfaced discontinuity whose major face is perpendicularto the direction of sound beam propagation.
d.2 mm (0.08 in.) diameter rough-surfaced discontinuity whose major face is parallel to thedirection of sound beam propagation.

Answer 81

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

Question 82

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 82

a.for angle beam contact testing.

Question 83

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 83

b.acoustic lenses.

Question 84

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 84

b.immersion testing.

Question 85

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 85

c.an electronic gate.

Question 86

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 86

d.resolution.

Question 87

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 87

a.refraction

Question 88

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 88

a.the angle of refraction.

Question 89

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 89

a.acoustic impedance.

Question 90

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 90

a.diverge (spread out) through the part.

Question 91

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 91

d.rayleigh waves.

Question 92

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 92

a.fresnel zone

Question 93

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 93

b.shear wave.

Question 94

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 94

c.Snell’s law.

Question 95

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 95

c.decrease.

Question 96

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 96

d.receiver-amplifier circuits.

Question 97

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 97

a.an A-scan display.

Question 98

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 98

a.an A-scan display.

Question 99

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 99

b.receiver-amplifier.

Question 100

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 100

a.a pulser.

Question 101

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 101

c.a clock.

Question 102

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 102

a.a C-scan display.

Question 103

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 103

b.a B-scan presentation.

Question 104

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 104

d.Immersion testing.

Question 105

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 105

c.detection of obliquely oriented discontinuities

Question 106

108. A type of data presentation most likely to be usedwith 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 106

c.a C-scan presentation.

Question 107

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 107

b.a bridge

Question 108

111. An amplitude type gate is necessary for all:
     a.shear wave examinations.
     b.longitudinal wave examinations.
     c.automatic examinations.
     d.manual examinations.

Answer 108

c.automatic examinations.

Question 109

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 109

b.a manipulator.

Question 110

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 110

d.location and size (plan view).

Question 111

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 111

c.a loss of amplitude from discontinuities.

Question 112

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 112

b.attenuation.

Question 113

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 113

b.It decreases the detected signal.

Question 114

116.Which material can only transmit longitudinal waves?
a.Machine oil.
b.Aluminum.
c.Ice.
d.Beryllium.

Answer 114

a.Machine oil.

Question 115

117.If the velocity of a longitudinal mode wave in a givenhomogeneous material is 0.625 cm/us at 13 mm
(0.5 in.) below the surface, what is the velocity at 51mm (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 115

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

Question 116

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 acousitc impedance.

Answer 116

c.Make it shorter.

Question 117

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 117

d.Edge effects

Question 118

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 118

d.a reference standard.

Question 119

121.Another name for fresnel zone is:
a.zone.
b.near field.
c.far field.
d.torrid zone

Answer 119

b.near field.

Question 120

122. Attenuation is a:
     a.test display characteristic.
     b.test material parameter.
     c.transducer characteristic.
     d.form of testing.

Answer 120

b.test material parameter.

Question 121

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 121

c.decreased

Question 122

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 122

c.angulate the transducer.

Question 123

125. The pulser circuit in an ultrasonic instrument is usedto:
     a.control the horizontal and vertical sweep.
     b.activate the transducer.
     c.control transducer timing between transmit andsweep.
     d.generate markers that appear on horizontalsweep

Answer 123

b.activate the transducer.

Question 124

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 124

b.an RF display.

Question 125

127. A B-scan display shows the relative:
     a.distance a discontinuity is from the transducerand its through-dimension thickness
     b.distance a discontinuity is from the transducerand its length in the direction of transducer travel.
     c.cross-sectional area of a discontinuity above apredetermined amplitude
     d.pulse height and time of arrival to produce aplan-view image.

Answer 125

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

Question 126

128.Surface (rayleigh) waves traveling on the top face of ablock:
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 arereflected from the lower edge.
d.are absorbed by a sharp edge corner

Answer 126

b.are reflected from a sharp edge corner.

Question 127

129.Surface (rayleigh) waves are more highly attenuated by a:
a.curved surface.
b.heavy couplant.
c.thin couplant.
d.sharp corner.

Answer 127

b.heavy couplant.

Question 128

130. The velocity of sound in a material is dependentupon the:
     a.frequency of the wave.
     b.wavelength.
     c.material properties.
     d.vibration cycle

Answer 128

c.material properties.

Question 129

131.To vary or change the wavelength of sound beingused to test a part, change the:
a.sound wave frequency.
b.diameter of the transducer.
c.electrical pulse voltage.
d.pulse repetition rate.

Answer 129

a.sound wave frequency.

Question 130

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 130

d.perform volumetric examinations of ferrous and nonferrous materials.

Question 131

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 131

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

Question 132

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 132

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

Question 133

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 133

d.adaptability for automated scanning.

Question 134

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 134

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

Question 135

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 135

b.help eliminate the formation of air bubbles.

Question 136

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 136

b.F = V/2T.

Question 137

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 137

a.decreases (becomes shorter).

Question 138

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 longitudinalaxis.

Answer 138

c. metal distance above the drilled hole

Question 139

141.When setting up a distance amplitude correctioncurve using three flat-bottom holes, sometimes thehole closest to the transducer gives less of a responsethan one or both of the other two. This could becaused by:
a.a hole that is too large.
b.near field effects.
c.impedance mismatch.
d.the acoustic velocity

Answer 139

b.near field effects.

Question 140

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 140

c.2-5 MHz

Question 141

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 141

a.acoustic impedance

Question 142

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 plasticwedge, and acoustic lenses.

Answer 142

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

Question 143

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 143

d.increase the water path.

Question 144

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 144

c.stays the same.

Question 145

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 145

a.between normal and the first critical angle

Question 146

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 146

a.1 MHz

Question 147

149.Refracted energy assumes a new direction ofpropagation when the is changed.
a.principal angle
b.reflected angle
c.critical angle
d.incident angle

Answer 147

d.incident angle

Question 148

150. The loss of energy as it propagates through material is the result of beam:
     a.interference.
     b.attenuation.
     c.absorption.
     d.reflection.

Answer 148

b.attenuation

Question 149

151. In selecting a suitable couplant, which of thefollowing characteristics would not affect then 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 149

c.Operating frequency of the transducer.

Question 150

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 150

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

Question 151

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 151

b.providing a method for standardizing the testsystem.

Question 152

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 152

d.refraction.

Question 153

155. If a discontinuity is oriented at an angle other than90° to the sound beam, the results may be a:
     a.loss of signal linearity.
     b.loss or lack of signal reflected from thediscontinuity.
     c.focusing of the sound beam.
     d.loss of interference phenomena.

Answer 153

b.loss or lack of signal reflected from thediscontinuity.

Question 154

156. A device that transforms electrical pulses intomechanical and vice versa utilizes:
     a.Snell’s law.
     b.piezoelectric principles.
     c.mode conversion principles.
     d.particle motion principles.

Answer 154

b.piezoelectric principles.

Question 155

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 theincident 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 arefracted wave without more information.

Answer 155

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

Question 156

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 156

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

Question 156

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 156

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

Question 157

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 157

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

Question 158

1. The wave mode that has multiple or varying wave velocities is:
   a.longitudinal waves.
   b.shear waves.
   c.transverse waves.
   d.lamb waves.

Answer 158

d.lamb waves.

Question 159

2. of the following would be consideredapplication(s) of ultrasonic techniques?
   a.Determination of a material’s coefficient ofexpansion.
   b.Study of a material’s metallurgical structure.
   c.Determination of a material’s chemicalcomposition.
   d.Evaluation of surface tension through capillaryaction.

Answer 159

b.Study of a material’s metallurgical structure.

Question 160

3. The only significant sound wave mode that travels through a liquid is a:
   a.shear wave.
   b.longitudinal wave.
   c.surface wave.
   d.rayleigh wave.

Answer 160

b.longitudinal wave.

Question 161

4. The acoustic impedance of a material is used to determine the:
   a.angle of refraction at an interface.
   b.attenuation within the material.
   c.relative amounts of sound energy coupled through and reflected at an interface.
   d.beam spread within the material.

Answer 161

c.relative amounts of sound energy coupled through and reflected at an interface.

Question 162

5. When angle beam contact testing a test piece,increasing the incident angle until the second critical angle is reached may result in:
   a.total reflection of a surface wave.
   b.45° refraction of the shear wave.
   c.production of a surface wave.
   d.a 90° angle of refraction for the wave.

Answer 162

c.production of a surface wave.

Question 163

6. Acoustic energy propagates in different modes. Which of the following represents a mode?
   a.High-frequency ultrasonic waves.
   b.A shear wave.
   c.The dissipation factor.
   d.The wave movement in the direction from the point where the energy was introduced.

Answer 163

b.A shear wave.

Question 164

7. The simple experiment where a stick in a glass of water appears disjointed at the water surface illustrates the phenomenon of:
   a.reflection.
   b.magnification.
   c.refraction.
   d.diffraction.

Answer 164

c.refraction.

Question 165

8. The crystal thickness and transducer frequency are related. The thinner the crystal:
   a.the lower the frequency.
   b.the higher the frequency.
   c.there is no appreciable effect.
   d.the lower the attenuation.

Answer 165

b.the higher the frequency.

Question 166

9. The random distribution of crystallographic direction in alloys with large crystalline structures is a factor in determining:
   a.the body-centered cubic crystal system.
   b.the angle of refraction.
   c.scattering of sound.
   d.material thickness.

Answer 166

c.scattering of sound.

Question 167

10. The length of the zone adjacent to a transducer in which fluctuations in sound pressure occur is mostly affected by the:
    a.frequency of the transducer.
    b.the sound beam exit point.
    c.length of transducer cable.
    d.diameter of the transducer.

Answer 167

d.diameter of the transducer.

Question 168

11.The differences in signals received from identical reflectors at different material distances from a transducer may be caused by:
a.material composition.
b.beam divergence.
c.acoustic impedance.
d.the piezoelectric effect

Answer 168

b.beam divergence.

Question 169

12.It is possible for a discontinuity smaller than the transducer to produce indications of fluctuating amplitude as the transducer is moved laterally if testing is being performed in the:
a.fraunhofer zone.
b.near field.
c.snell field.
d.shadow zone.

Answer 169

b.near field

Question 170

13. In immersion testing, the near-field effects of a transducer may be eliminated by:
    a.increasing transducer frequency.
    b.using a larger diameter transducer.
    c.using an appropriate water path.
    d.using a focused transducer.

Answer 170

c.using an appropriate water path.

Question 171

14. In Figure 1, assuming a uniform beam pattern, what relationship would you expect to exist between the amplitudes of the reflected laminar signals at positions A and B?
    a.12dB difference.
    b.Equal amplitudes.
    c.2 to 1.
    d.3 to 1.

Answer 171

c.2 to 1.

Question 172

15. In the far field of a uniform ultrasonic beam, soundintensity is the beam centerline.
    a.minimum at
    b.maximum at
    c.maximum throughout twice the angle
    siny=C/Df
    where C is acoustic velocity, D is crystal diameter, and f is frequency at
    d.not related to orientation of

Answer 172

b.maximum at

Question 173

16. Which of the following may result in a long, narrow rod if the beam divergence results in a reflection from a side of the test piece before the sound wave reaches the back surface?
    a.Multiple indications before the first back reflection.
    b.Indications from multiple surface reflections.
    c.Conversion from the longitudinal mode to shear mode at the perimeter of the beam.
    d.Loss of front-surface indications.

Answer 173

c.Conversion from the longitudinal mode to shear mode at the perimeter of the beam.

Question 174

17. Where does beam divergence occur?
    a.Near field.
    b.Far field.
    c.At the crystal.
    d.At the interface.

Answer 174

b.Far field.

Question 175

18. As frequency increases in ultrasonic testing, the angle
    of beam divergence of a given diameter crystal:
    a.decreases.
    b.remains unchanged.
    c.increases.
    d.varies uniformly through each wavelength.

Answer 175

a.decreases.

Question 176

19. As the radius of curvature of a curved lens is increased, the focal length of the lens:
    a.increases.
    b.decreases.
    c.remains the same.
    d.cannot be determined unless the frequency isknown.

Answer 176

a.increases.

Question 177

20. When examining materials for planar flaws oriented parallel to the part surface, what testing method is most often used?
    a.Angle beam.
    b.Through-transmission.
    c.Straight beam.
    d.Dual crystal.

Answer 177

c.Straight beam.

Question 178

21. If a contact angle beam transducer produces a 45° shear wave in steel, the angle produced by the same transducer in an aluminum specimen would be:(Vsteel = 0.323 cm/μs; VAL= 0.310 cm/μs)
    a.less than 45°.
    b.greater than 45°.c.45°.
    d.unknown; more information is required.
    A.

Answer 178

a.less than 45°.

Question 179

22. Rayleigh waves are influenced most by discontinuities located:
    a.close to or on the surface.
    b.1 wavelength below the surface.
    c.3 wavelengths below the surface.
    d.6 wavelengths below the surface.

Answer 179

a.close to or on the surface.

Question 180

23.The ultrasonic testing technique in which finger damping is most effective in locating a discontinuity is the:
a.shear wave technique.
b.longitudinal wave technique.
c.surface wave technique.
d.compressional wave technique.

Answer 180

c.surface wave technique.

Question 181

24. Lamb waves can be used to detect:
    a.laminar-type discontinuities near the surface of a thin material.
    b.lack of fusion in the center of a thick weldment.
    c.internal voids in diffusion bonds.
    d.thickness changes in heavy plate material.

Answer 181

a.laminar-type discontinuities near the surface of a thin material.

Question 182

25.The ratio of the velocity of sound in water compared to that for aluminum or steel is approximately:
a.1:8.
b.1:4.
c.1:3.
d.1:2.

Answer 182

b.1:4.

Question 183

26. Which of the following scanning methods could be classified as an immersion-type test?
    a.Contact angle beam testing.
    b.Surface wave technique with a plastic transducer wedge.
    c.Scanning with a wheel-type transducer with the transducer inside a liquid-filled tire.
    d.Through-transmission technique with shearwaves

Answer 183

c.Scanning with a wheel-type transducer with the transducer inside a liquid-filled tire.

Question 184

27. In an immersion test of a piece of steel or aluminum,the water distance appears on the display as a fairly wide space between the initial pulse and the front-surface reflection because of:
    a.reduced velocity of sound in water as compared to the test specimen.
    b.increased velocity of sound in water as comparedto the test specimen.
    c.temperature of the water.
    d.viscosity of the water

Answer 184

a.reduced velocity of sound in water as compared to the test specimen

Question 185

28.Using the immersion method, a distance-amplitude curve (DAC) for a 19 mm (0.75 in.) diameter, 5 MHz transducer shows the high point of the DAC at the B/51mm (2 in.) block. One day later, the high point of the DAC for the same transducer is at the
J/102 mm (4 in.) block. Assuming that calibration has not changed, this would indicate that the transducer:
a.is improving in resolution.
b.is becoming defective.
c.has the beam of a contact testing transducer.
d.has a better definition

Answer 185

b.is becoming defective.

Question 186

29. What law can be used to calculate the angle of refraction within a metal for both longitudinal and shear waves?
    a.Poisson’s ratio law.
    b.Snell’s law.
    c.Fresnel’s field law.
    d.Charles’ law.

Answer 186

b.Snell’s law

Question 187

30. At an interface between two different materials, an impedance difference results in:
    a.reflection of the entire incident energy at the interface.
    b.absorption of sound.
    c.division of sound energy into transmitted andreflected modes.
    d.refraction of the entire incident energy at theinterface.

Answer 187

c.division of sound energy into transmitted andreflected modes.

Question 188

31. When using focused transducers, nonsymmetry in a propagated sound beam may be caused by:
    a.backing material variations.
    b.mode conversion.
    c.diffraction characteristics.
    d.irregular sound beam exit point.

Answer 188

a.backing material variations.

Question 189

32. Ultrasonic wheel units may be used for which of the following types of examination?
    a.Contact testing of aluminum plates.
    b.Through-transmission testing of impeller shafts.
    c.Longitudinal wave and/or shear wave examination.
    d.Angle beam testing on beam-to column T-joint complete penetration welds.

Answer 189

c.Longitudinal wave and/or shear wave examination.

Question 190

33. During straight beam testing, test specimens with nonparallel front and back surfaces can cause:
    a.partial or total loss of back reflection.
    b.no loss in back reflection.
    c.a widened (broad) back-reflection indication.
    d.a focused (narrow) back-reflection indication.

Answer 190

a.partial or total loss of back reflection.

Question 191

34. In the immersion technique, the distance between the face of the transducer and the test surface (water path) is usually adjusted so that the time required to send the sound beam through the water is:
    a.equal to the time required for the sound to travel through the test piece.
    b.greater than the time required for the sound to travel through the test piece.
    c.less than the time required for the sound to travel through the test piece.
    d.greater or less than the time required for the sound to travel through the test piece depending on water temperature and wave characteristics

Answer 191

c.less than the time required for the sound to travel through the test piece

Question 192

35. In a B-scan display, the length of a screen indication from a discontinuity is related to:
    a.a discontinuity’s thickness as measured parallel to the ultrasonic beam.
    b.the discontinuity’s length in the direction of the transducer travel.
    c.the horizontal baseline elapsed time from left to right.
    d.the vertical and horizontal directions representing the area over which the transducer was scanned

Answer 192

b.the discontinuity’s length in the direction of the transducer travel.

Question 193

36.Which circuit triggers the pulser and sweep circuits in an A-scan display?
a.Receiver-amplifier.
b.Power supply.
c.Clock.
d.Damping.

Answer 193

c.Clock.

Question 194

37.On an A-scan display, the dead zone, refers to the:
a.distance contained within the near field.
b.area outside the beam spread.
c.distance covered by the front-surface pulse width and recovery time.
d.area between the near field and the far field

Question 195

38.On an A-scan display, what represents the intensity of a reflected beam?

a.Echo pulse width.
b.Horizontal screen location.
c.Signal brightness.
d.Signal amplitude.

Answer 195

d.Signal amplitude.

Question 196

39. Of the following scan types, which one can be used to produce a recording of discontinuitiy areas superimposed over a plan view of the test piece?
    a.A-scan.
    b.B-scan.
    c.C-scan.
    d.D-scan.

Answer 196

c.C-scan.

Question 197

40. In immersion testing in a small tank, a manually operated manipulator is used to:
    a.manipulate the pulser/receiver unit and the display.
    b.set the proper transducer angle.
    c.set the proper index function.
    d.set the proper bridge distance

Answer 197

b.set the proper transducer angle

Question 198

41. In straight (normal) beam contact testing, which of the following would NOT result in a reduction in the back-surface reflection amplitude?
    a.the usage of a high-viscosity couplant.
    b.a discontinuity that is normal to the beam.
    c.a near-surface discontinuity that cannot beresolved from the main bang (initial pulse).
    d.a coarse-grain material.

Answer 198

a.the usage of a high-viscosity couplant.

Question 199

42. A 152 mm (6 in.) diameter rod is being inspected for centerline cracks. The A-scan presentation for one complete path through the rod is as shown in Figure 2.The alarm gate should:
    a.be used between points A and E.
    b.be used at point D only.
    c.be used between points B and D.
    d.not be used for this application.

Answer 199

c.be used between points B and D.

Question 200

43. In an automatic scanning immersion unit, the bridge or carriage serves to:
    a. support the manipulator and scanner tube and to move it about transversely and longitudinally.
    b.control the angular and transverse positioning of the scanner tube.
    c.control the vertical and angular positioning of the scanner tube.
    d.raise and lower the transducer

Answer 200

a. support the manipulator and scanner tube and to move it about transversely and longitudinally.

Question 201

44. When adjusting the discontinuity-locating rule for a shear wave weld inspection, the zero point on the rule must coincide with the:
    a.sound beam exit point of the wedge.
    b.point directly over the discontinuity.
    c.wheel transducer.
    d.circular scanner.

Answer 201

a.sound beam exit point of the wedge

Question 202

45. A special scanning device with the transducer mounted in a tire-like container filled with couplant is commonly called:
    a.a rotating scanner.
    b.an axial scanner.
    c.a wheel transducer.
    d.a circular scanner

Answer 202

c.a wheel transducer.

Question 203

46. Which best describes a typical display of a crack whose major surface is perpendicular to the ultrasonic beam?
    a.A broad indication.
    b.A sharp indication.
    c.The indication will not show due to improper orientation.
    d.A broad indication with high amplitude

Answer 203

b.A sharp indication.

Question 204

47. A primary purpose of a reference standard is to:
    a.provide a guide for adjusting instrument controls to reveal discontinuities that are considered harmful to the end use of the product.
    b.give the technician a tool for determining exact discontinuity size.
    c.provide assurance that all discontinuities smaller than a certain specified reference reflector are capable of being detected by the test.
    d.provide a standard reflector, which exactly simulates natural discontinuities of a critical size.

Answer 204

a.provide a guide for adjusting instrument controls to reveal discontinuities that are considered harmful to the end use of the product.

Question 205

48. Compensation for the variation in echo height related to variations in discontinuity depth in the test material is known as:
    a.transfer.
    b.attenuation.
    c.distance-amplitude correction.
    d.interpretation

Answer 205

b.attenuation.

Question 206

49. Which of the following is a reference reflector that is not dependent on beam angle?
    a.A flat-bottom hole.
    b.A V-notch.
    c.A side-drilled hole which is parallel to the plate surface and perpendicular to the sound path.
    d.A disk-shaped laminar reflector.

Answer 206

c.A side-drilled hole which is parallel to the plate surface and perpendicular to the sound path.

Question 207

50. During a straight beam ultrasonic test, a discontinuity indication is detected that is small in amplitude compared to the loss in amplitude of back reflection. The orientation of this discontinuity is probably:
    a.parallel to the test surface.
    b.perpendicular to the sound beam.
    c.parallel to the sound beam.
    d.at an angle to the test surface.

Answer 207

d.at an angle to the test surface

Question 208

51. A discontinuity is located having an orientation such that its long axis is parallel to the sound beam. The indication from such a discontinuity will be:
    a.large in proportion to the length of the discontinuity.
    b.small in proportion to the length of the discontinuity.
    c.representative of the length of the discontinuity.
    d.such that complete loss of back reflection will result.

Answer 208

b.small in proportion to the length of the discontinuity.

Question 209

52. Gas discontinuities are reduced to flat disks or other shapes parallel to the surface by:
    a.rolling.
    b.machining.
    c.casting.
    d.welding.

Answer 209

a.rolling.

Question 210

53. In which zone does the amplitude of an indication from a given discontinuity diminish exponentially as the distance increases?
    a.Far-field zone.
    b.Near-field zone.
    c.Dead zone.
    d.Fresnel zone.

Answer 210

a.Far-field zone.

Question 211

revisar cambibo not revisar propagacion del sonido
54. A smooth, flat discontinuity whose major plane is perpendicular to the direction of sound propagation may be indicated by:
a.an echo amplitude comparable in magnitude to the back-surface reflection, as well as complete loss of the back-surface reflection.
b.an echo whose amplitude is steady across the discontinuity surface.
c.an increase in backwall with no response from discontinuity.
d.the absence of an indication.

Answer 211

b.an echo whose amplitude is steady across the discontinuity surface.

Question 212

55. Using a pulse echo technique, if the major plane of a flat discontinuity is oriented at some angle other than perpendicular to the direction of sound propagation,the result may be:
    a.loss of signal linearity.
    b.loss or lack of a received discontinuity echo.
    c.focusing of the sound beam.
    d.loss of interference phenomena

Answer 212

b.loss or lack of a received discontinuity echo.

Question 213

56. As transducer diameter decreases, the beam spread:
    a.decreases.
    b.remains the same.
    c.increases.
    d.becomes conical in shape

Answer 213

c.increases.

Question 214

57. A set of standard reference blocks with the same geometrical configuration and dimensions other than the size of the calibration reflectors, for example,
    flat-bottom holes, is called a set of:
    a.distance-amplitude standards.
    b.area-amplitude standards.
    c.variable frequency blocks.
    d.beam spread measuring blocks

Answer 214

b.area-amplitude standards..

Question 215

58. The angle at which 90° refraction of a longitudinal sound wave is reached is called the:
    a.angle of incidence.
    b.first critical angle.
    c.angle of maximum reflection.
    d.second critical angle. B.21

Answer 215

b.first critical angle

Question 216

59. The control of voltage supplied to the vertical deflection plates of the instrument display in an A-scan UT setup is performed by the:
    a.sweep generator.
    b.pulser.
    c.amplifier circuit.
    d.clock timer. E.238

Answer 216

c.amplifier circuit.

Question 217

60. Attenuation is a difficult quantity to measure accurately, particularly in solid materials, at the test frequencies normally used. The overall result usually observed includes other loss mechanisms, such as:
    a.temperature.
    b.scan rate.
    c.fine grain structure.
    d.beam spread. B.15. 164

Answer 217

d.beam spread.

Question 218

61. The most commonly used method of producing shear waves in a flat test part when inspecting by the immersion method is by:
    a.transmitting longitudinal waves into a part in adirection perpendicular to its front surface.
    b.using two crystals vibrating at differentfrequencies.
    c.angulating the search tube or manipulator to the proper angle.
    d.using Y-cut quartz crystal

Answer 218

c.angulating the search tube or manipulator to the proper angle.

Question 219

62. Large grains in a metallic test specimen usually result in:
    a.scatter, which becomes less pronounced as grain size approaches wavelength.
    b.increased penetration.
    c.have no effect if a higher frequency is used.
    d.large grass or hash or noise indications.

Answer 219

d.large grass or hash or noise indications.

Question 220

63. The total energy losses occurring in all materials is called:
    a.attenuation.
    b.scatter.
    c.beam spread.
    d.interface.

Answer 220

a.attenuation.

Question 221

64. Delay-tip (stand-off) type contact transducers are primarily used for:
    a.discontinuity detection.
    b.sound wave characterization.
    c.thickness measurement or discontinuity detectionin thin materials.
    d.attenuation measurements.

Answer 221

c.thickness measurement or discontinuity detectionin thin materials.

Question 222

65. Acoustical lenses are commonly used for contour correction. When scanning the inside of a pipe section by the immersion method, use a:
    a.focused cup lens.
    b.convex lens.
    c.concave lens.
    d.variable pitch lens A.277-278; B.53

Answer 222

b.convex lens.

Question 223

66. In Figure 3, transducer A is being used to establish:
    a.verification of wedge angle.
    b.sensitivity calibration.
    c.resolution.
    d.an index point.

Answer 223

d.an index point.

Question 224

67. In Figure 3, transducer C is being used to check:
    a.distance calibration.
    b.resolution.
    c.sensitivity calibration.
    d.verification of wedge angle

Answer 224

c.sensitivity calibration.

Question 225

68. In Figure 3, transducer D is being used to check:
    a.sensitivity calibration.
    b.distance calibration.
    c.resolution.
    d.verification of wedge angle.

Answer 225

d.verification of wedge angle.

Question 226

69. When the incident angle is chosen to be between the first and second critical angles, the ultrasonic wave generated within the part will be:
    a.longitudinal.
    b.shear.
    c.surface.
    d.lamb.

Answer 226

b.shear.

Question 227

70. In Figure 4, transducer B is being used to check:
    a.the verification of wedge angle.
    b.resolution.
    c.sensitivity calibration.
    d.distance calibration

Answer 227

b.resolution.

Question 228

71. The angle at which 90° refraction of the shear wave mode occurs is called the:
    a.first critical angle.
    b.second critical angle.
    c.third critical angle.
    d.angle of reflection. B21

Answer 228

b.second critical angle.

Question 229

72. In a water immersion test, ultrasonic energy is transmitted into steel at an incident angle of 14°.What is the angle of the refracted shear wave within the material?
    VS = 3.2 × 105 cm/s
    VW = 1.5 × 105 cm/s
    (Trigonometry Tables Required)
    a.45°
    b.23°
    c.31°
    d.13°

Answer 229

c.31°

Question 230

73. If you were requested to design a plastic shoe to generate a rayleigh wave in aluminum, what would be the incident angle of the ultrasonic energy?
    VA = 3.1 × 105 cm/s
    VP = 2.6 × 105 cm/s
    (Trigonometry Tables Required).
    a.37°
    b.57°
    c.75°
    d.48°

Answer 230

b.57°

Question 231

74. Compute the wavelength of ultrasonic energy in lead at 1 MHz.
    VL = 2.1 × 105 cm/s
    V = λ × F
    a.0.21 cm
    b.21 cm
    c.0.48 cm
    d.4.8 × 105 cm

Answer 231

a.0.21 cm

Question 232

75. For aluminum and steel, the longitudinal velocity is approximately the shear velocity.
    a.equal to
    b.twice
    c.half of
    d.four times

Answer 232

b.twice

Question 233

76. Water travel distance for immersion inspections should be:
    a.such that the second front reflection does not appear between the first front and back reflections.
    b.exactly 76 mm (3 in.).
    c.less than 76 mm (3 in.).
    d.always equal to the thickness of the material being inspected. B.149-150

Answer 233

a.such that the second front reflection does not appear between the first front and back reflections.

Question 234

77. The electronic circuitry that allows selection and processing of only those signals relating to discontinuities that occur in specific zones of a part is called:
    a.an electronic gate.
    b.an electronic attenuator.
    c.a distance amplitude correction circuit.
    d.a fixed marker

Answer 234

a.an electronic gate.

Question 235

78. When conducting a contact ultrasonic test, the grass or irregular signals that appear in the screen display of the area being inspected could be caused by:
    a.fine grains in the structure.
    b.dirt in the water couplant.
    c.coarse grains in the structure.
    d.a thick but tapered back surface.

Answer 235

c.coarse grains in the structure

Question 236

79. In inspecting a 102 mm (4 in.) diameter threaded steel cylinder for radial cracks extending from the root of the threads, it would be preferable to transmit:
    a.shear waves at an angle to the threads.
    b.longitudinal waves from the end of the cylinder and perpendicular to the direction of the thread roots.
    c.surface waves perpendicular to the thread roots.
    d.shear waves around the circumference of the cylinder.

Answer 236

b.longitudinal waves from the end of the cylinder and perpendicular to the direction of the thread roots.

Question 237

80. In an immersion inspection of raw steel material, the water travel distance should be:
    a.exactly 76 mm (3 in.).
    b.equal to 76 mm (3 in.) ±13 mm (±0.5 in.).
    c.greater than one-fourth the thickness of the part.
    d.equal to the thickness of a material

Answer 237

c.greater than one-fourth the thickness of the part.

Question 238

81. The angle formed by an ultrasonic wave as it enters a medium of different velocity than the one from which it came and a line drawn perpendicular to the
    interface between the two media is called the angle of:
    a.incidence.
    b.refraction.
    c.rarefaction.
    d.reflection.

Answer 238

b.refraction.

Question 239

82. The process of adjusting an instrument or device to a reference standard is referred to as:
    a.angulation.
    b.scanning.
    c.correcting for distance-amplitude variations.
    d.calibration.

Question 240

83. A grouping of a number of crystals in one transducer,with all contact surfaces in the same plane and vibrating in phase with each other to act as a single transducer is called a:
    a.focusing crystal.
    b.crystal mosaic.
    c.scrubber.
    d.single-plane manipulator. B.51

Answer 240

b.crystal mosaic

Question 241

84. The angle of reflection is:
    a.equal to the angle of incidence.
    b.dependent on the couplant used.
    c.dependent on the frequency used.
    d.equal to the angle of refraction

Answer 241

a.equal to the angle of incidence.

Question 242

85. The angular position of the reflecting surface of a planar discontinuity with respect to the entry surface is referred to as:
    a.the angle of incidence.
    b.the angle of refraction.
    c.the orientation of the discontinuity.
    d.angle of reflection

Answer 242

c.the orientation of the discontinuity.

Question 243

86. A short burst of alternating electrical energy is called:
    a.a continuous wave.
    b.a peaked DC voltage.
    c.an ultrasonic wave.
    d.a pulse.

Answer 243

d.a pulse.

Question 244

87. In ultrasonic testing, the time duration of the transmitted pulse is referred to as the:
    a.pulse length or pulse width.
    b.pulse amplitude.
    c.pulse shape.
    d.pulse distortion A.183 B81,197

Answer 244

a.pulse length or pulse width.

Question 245

88. The phenomenon by which a wave strikes a boundary and changes the direction of it spropagation within the same medium is referred to as:
    a.divergence.
    b.impedance.
    c.angulation.
    d.reflection.

Answer 245

d.reflection.

Question 246

89. The change in direction of an ultrasonic beam when it passes from one medium to another whose velocity differs from that of the first medium is called:
    a.refraction.
    b.rarefaction.
    c.angulation.
    d.reflection.

Answer 246

a.refraction.

Question 247

90. Which of the following modes of vibration exhibits the shortest wavelength at a given frequency and in a given material?
    a.A longitudinal wave.
    b.A compression wave.
    c.A shear wave.
    d.A surface wave.

Answer 247

d.A surface wave.

Question 248

91.In general, shear waves are more sensitive to small discontinuities than longitudinal waves for a given frequency and in a given material because:
a.the wavelength of shear waves is shorter than thewavelength of longitudinal waves.
b.shear waves are not as easily dispersed in the material.
c.the direction of particle vibration for shear waves is more sensitive to discontinuities.
d.the wavelength of shear waves is longer than thewavelength of longitudinal waves.

Answer 248

a.the wavelength of shear waves is shorter than thewavelength of longitudinal waves.

Question 249

92. In general, which of the following modes of vibration would have the greatest penetrating power in acoarse-grained material if the frequency of the waves is the same?
    a.Longitudinal waves.
    b.Shear waves.
    c.Transverse waves.
    d.Rayleigh waves

Answer 249

a.Longitudinal waves.

Question 250

93. A testing technique in which the crystal or transducer is parallel to the test surface and ultrasonic waves enter the material being tested in a direction perpendicular to the test surface is:
    a.straight beam testing.
    b.angle beam testing.
    c.surface wave testing.
    d.lamb wave.

Answer 250

a.straight beam testing

Question 251

94. The distance from a given point on an ultrasonic wave to the next corresponding point is referred to as:
    a.frequency.
    b.wavelength.
    c.velocity.
    d.pulse length

Answer 251

b.wavelength.

Question 252

95. The speed with which ultrasonic waves travel through a material is known as:
    a.velocity.
    b.pulse repetition rate
    c.pulse recovery rate.
    d.ultrasonic response.

Answer 252

a.velocity.

Question 253

96. A substance that reduces the surface tension of a liquid is referred to as:
    a.a couplant.
    b.an ultrasonic dampener.
    c.a wetting agent.
    d.a solvent.

Answer 253

c.a wetting agent.

Question 254

97. The ultrasonic transducers most commonly used for discontinuity testing utilize:
    a.magnetostriction principles.
    b.piezoelectric principles.
    c.mode conversion principles.
    d.relative dialectric principles.

Answer 254

b.piezoelectric principles.

Question 255

98. Mechanical and electrical stability, insolubility in liquids, and resistance to aging are three advantages of transducers made of:
    a.lithium sulfate.
    b.barium titanate.
    c.quartz.
    d.rochelle salts.

Answer 255

c.quartz.

Question 256

99. The sin a1/V1=sina2/V2
    formula is referred to as:
    to as:
    a.the acoustical impedance ratio formula.
    b.the phase conversion formula.
    c.the fresnel zone formula.
    d.Snell’s law.

Answer 256

d.Snell’s law.

Question 257

100. The sin a1/V1=sina2/V2
     formula is referred to as:
     to as:
     a.angular relationships.
     b.phase velocities.
     c.amount of reflected sound energy.
     d.acoustic impedance

Answer 257

a.angular relationships.

Question 258

101. The amount of energy reflected from a discontinuity is not dependent on the:
     a.size of the discontinuity.
     b.orientation of the discontinuity.
     c.type of discontinuity.
     d.filter setting.

Answer 258

d.filter setting.

Question 259

102. If an ultrasonic wave is transmitted through an interface of two materials in which the first material has a higher acoustic impedance value but the same velocity value as the second material, the angle of refraction will be:
     a.greater than the angle of incidence.
     b.less than the angle of incidence.
     c.the same as the angle of incidence.
     d.beyond the critical angle.

Answer 259

c.the same as the angle of incidence.

Question 260

103. Which one of the following frequencies would probably result in the greatest ultrasonic attenuation losses?
     a.1 MHz
     b.2.25 MHz
     c.10 MHz
     d.25 MHz

Answer 260

d.25 MHz

Question 261

104. The product of the sound velocity and the density of a material is known as the:
     a.refraction value of the material.
     b.acoustic impedance of the material.
     c.elastic constant of the material.
     d.Poisson’s ratio of the material. B15-16

Answer 261

b.acoustic impedance of the material

Question 262

105. The amplifier range over which the unsaturated signal response increases in amplitude in proportion to the discontinuity surface area is the:
     a.sensitivity range.
     b.vertical linearity range.
     c.selectivity range.
     d.horizontal linearity range. A.195

Answer 262

b.vertical linearity range.

Question 263

106. What kind of waves travel at a velocity slightly less than shear waves and their mode of propagation is both longitudinal and transverse with respect to the surface?
     a.Rayleigh waves.
     b.Transverse waves.
     c.L-waves.
     d.Longitudinal waves.

Answer 263

a.Rayleigh waves.

Question 264

107. Which ultrasonic test frequency would probably provide the best penetration in a 30 cm (12 in.) thick specimen of coarse-grained steel?
     a.1 MHz
     b.2.25 MHz
     c.5 MHz
     d.10 MHz

Answer 264

a.1 MHz

Question 265

108. During immersion testing of an ASTM Ultrasonic Standard Reference Block, a B-scan presentation system will show a:
     a.plan view of the block, showing the area and position of the hole bottom as seen from the entry surface.
     b.basic test pattern showing the height of an indication from the hold bottom and its location in depth from the entry surface.
     c.cross section of the reference block, showing the top and bottom surfaces of the block and the location of the hole bottom in the block.
     d.cross-sectional view presentation with a vertical signal representing the hole bottom and the horizontal position representing its depth position.

Answer 265

c.cross section of the reference block, showing the top and bottom surfaces of the block and the location of the hole bottom in the block.

Question 266

109. Properties of shear or transverse waves used for ultrasonic testing include:
     a.particle motion normal to propagation direction, and a propagation velocity that is about one-half the longitudinal wave velocity in the same material.
     b.exceptionally high sensitivity due to low attenuation resulting from longer wavelengths when propagating through water.
     c.high coupling efficiency because shear waves are less sensitive to surface variables when traveling from a coupling liquid to the part.
     d.high sensitivity as a result of having a greater wave velocity than longitudinal waves in the samematerial.

Answer 266

a.particle motion normal to propagation direction, and a propagation velocity that is about one-half the longitudinal wave velocity in the same material.

Question 267

110. One of the most common applications of ultrasonic tests employing shear waves is for the:
     a.detection of discontinuities in welds,tube and pipe.
     b.determination of elastic properties of metallic products.
     c.detection of laminar discontinuities in heavy plate.
     d.measurement of thickness of thin plate.

Answer 267

a.detection of discontinuities in welds,tube and pipe.

Question 268

111. Significant errors in ultrasonic thickness measurement can occur if:
     a.the test frequency is varying at a constant rate.
     b.the velocity of propagation deviates substantially from an assumed constant value for a given material.
     c.water is employed as a couplant between the transducer and the part being measured.
     d.the echo-to-echo mode is used

Answer 268

b.the velocity of propagation deviates substantially from an assumed constant value for a given material.

Question 269

112. Generally, the best ultrasonic testing method for detecting discontinuities oriented along the fusion zone in a welded plate is:
     a.an angle beam contact method using surface waves.
     b.a contact test using a straight longitudinal wave
     c.an immersion test using surface waves.
     d.an angle beam method using shear waves

Answer 269

d.an angle beam method using shear waves

Question 270

113. An ultrasonic testing instrument that displays pulsesrepresenting the magnitude of reflected ultrasound asa function of time or depth of metal is said tocontain:
     a.a continuous wave.
     b.an A-scan presentation.
     c.a B-scan presentation.
     d.a C-scan presentation.

Answer 270

b.an A-scan presentation.

Question 271

114. At a water-steel interface, the angle of incidence in water is 7°. The principal mode of vibration that exists in the steel is:
     a.longitudinal.
     b.shear.
     c.lamb.
     d.surface. B.22

Answer 271

a.longitudinal.

Question 272

115. In a liquid medium, the only mode of vibration that can exist is:
     a.longitudinal.
     b.shear.
     c.lamb.
     d.surface.

Answer 272

a.longitudinal.

Question 273

116. In an ultrasonic instrument, the number of pulses produced by an instrument in a given period of time is known as the:
     a.pulse length of the instrument.
     b.pulse recovery time.
     c.frequency.
     d.pulse repetition frequency.

Answer 273

d.pulse repetition frequency.

Question 274

117. In a basic pulse echo ultrasonic instrument, the component that coordinates the action and timing of other components is called a:
     a.display unit.
     b.receiver.
     c.marker circuit or range marker circuit.
     d.timing section. A186-187

Answer 274

d.timing section.

Question 275

118. In a basic pulse echo ultrasonic instrument, the component that produces the voltage that activates the transducer is called:
     a.an amplifier.
     b.a receiver.
     c.a pulser.
     d.a synchronizer.

Answer 275

c.a pulser.

Question 276

119. In a basic pulse echo ultrasonic instrument, the component that produces the time baseline is called a:
     a.sweep circuit.
     b.receiver.
     c.pulser.
     d.synchronizer

Answer 276

a.sweep circuit.

Question 277

120. In a basic pulse echo ultrasonic instrument, the component that produces visible signals on the screen which are used to measure distance is called a:
     a.sweep circuit.
     b.marker circuit.
     c.receiver circuit.
     d.synchronizer A180, 182, 561

Answer 277

b.marker circuit.

Question 278

121 .Most basic pulse echo ultrasonic instruments use:
a.automatic readout equipment.
b.an A-scan presentation.
c.a B-scan presentation.
d.a C-scan presentation.

Answer 278

b.an A-scan presentation.

Question 279

122. The instrument displays a plan view of the part outline and discontinuities when using:
     a.automatic readout equipment.
     b.an A-scan presentation.
     c.a B-scan presentation.
     d.a C-scan presentation. A1 C19

Answer 279

d.a C-scan presentation.

Question 280

123. The incident angles at which 90° refraction of longitudinal and shear waves occurs are called the:
     a.normal angles of incidence.
     b.critical angles.
     c.angles of maximum reflection.
     d.mode angles.

Answer 280

b.critical angles.

Question 281

124. Compression waves whose particle displacement is parallel to the direction of propagation are called:
     a.longitudinal waves.
     b.shear waves.
     c.lamb waves.
     d.rayleigh waves

Answer 281

a.longitudinal waves.

Question 282

125. The mode of vibration that is quickly damped out when testing by the immersion method is:
     a.longitudinal waves.
     b.shear waves.
     c.transverse waves.
     d.surface waves. A46

Answer 282

d.surface waves.

Question 283

126.The motion of particles in a shear wave is:
a.parallel to the direction of propagation of theultrasonic beam.
b.transverse to the direction of beam propagation.
c.limited to the material surface and elliptical inmotion.
d.polarized in a plane at 45° to the direction of beam propagation.

Answer 283

b.transverse to the direction of beam propagation.

Question 284

127. An ultrasonic longitudinal wave travels in aluminum with a velocity of 635 000 cm/s and has a frequency of 1 MHz. The wavelength of this ultrasonic wave is:
     a.6.35 mm (0.25 in.).
     b.78 mm (3.1 in.).
     c.1.9 m (6.35 ft).
     d.30 000 Å.

Answer 284

a.6.35 mm (0.25 in.).

Question 285

128. The refraction angle of longitudinal ultrasonic waves passing from water into a metallic material at angles other than normal to the interface is primarily a function of the:
     a.impedance ratio (r = ZwZm) of water to metal.
     b.relative velocities of sound in water and metal.
     c.frequency of the ultrasonic beam.
     d.density ratio of water to metal

Answer 285

b.relative velocities of sound in water and metal.

Question 286

129. In contact testing, shear waves can be induced in the test material by:
     a.placing an X-cut crystal directly on the surface of the materials and coupling through a film of oil.
     b.using two transducers on opposite sides of the test specimen.
     c.placing a spherical acoustic lens on the face of the transducer.
     d.using a transducer mounted on a plastic wedge so that sound enters the part at an angle.

Answer 286

d.using a transducer mounted on a plastic wedge so that sound enters the part at an angle.

Question 287

130. As frequency increases in ultrasonic testing, the angle of beam divergence of a given diameter crystal:
     a.decreases.
     b.remains unchanged.
     c.increases.
     d.varies uniformly through each wavelength. A96, 211

Answer 287

a.decreases.

Question 288

131. Which of the following is not an advantage of contact ultrasonic transducers (probes) adapted with plastic shoes?
     a.Most of the crystal wear is eliminated.
     b.Adaptation to curved surfaces is permitted.
     c.Sensitivity is increased.
     d.Ultrasound is allowed to enter a part’s surface at oblique angles

Answer 288

c.Sensitivity is increased

Question 289

132. The velocity of sound is the lowest in:
     a.air.
     b.water.
     c.aluminum.
     d.plastic.

Answer 289

a.air.

Question 290

133. A longitudinal ultrasonic wave is transmitted from water into steel at an angle of 5° from the normal. In such a case, the refracted angle of the transverse wave is:
     a.less than the refracted angle of the longitudinal wave.
     b.equal to the refracted angle of the longitudinal wave.
     c.greater than the refracted angle of the longitudinal wave.
     d.not present at all.

Answer 290

a.less than the refracted angle of the longitudinal wave.

Question 291

134. The velocity of longitudinal waves is the highest in:
     a.water.
     b.air.
     c.aluminum.
     d.plastic

Answer 291

c.aluminum.

Question 292

135. In steel, the velocity of sound is greatest in:
     a.longitudinal waves.
     b.shear waves.
     c.surface waves.
     d.lamb waves.

Answer 292

a.longitudinal waves

Question 293

136. The acoustic impedance is:
     a.used to calculate the angle of reflection.
     b.the product of the density of the material and the velocity of sound in the material.
     c.found by Snell’s law.
     d.used to determine resonance values.

Answer 293

b.the product of the density of the material and the velocity of sound in the material.

Question 294

137. Thin sheet may be inspected with the ultrasonic wave directed normal to the surface by observing the:
     a.amplitude of the front-surface reflection.
     b.multiple reflection pattern.
     c.attenuation rate.
     d.ratio of shear and longitudinal velocities.

Question 295

138. A diagram in which the entire circuit stage or sections are shown by geometric figures and the path of the signal or energy by lines and/or arrows is called a:
     a.schematic diagram.
     b.blueprint.
     c.block diagram.
     d.circuit layout. A85 157

Question 296

139. A void caused by gas entrapped in a casting is called:
     a.a burst.
     b.a cold shut.
     c.flaking.
     d.a blowhole.

Answer 296

d.a blowhole.

Question 297

140. A discontinuity that occurs during the casting of molten metal which may be caused by the splashing, surging, interrupted pouring, or the meeting of two streams of metal coming from different directions is called:
     a.a burst.
     b.a cold shut.
     c.flaking.
     d.a blowhole.

Answer 297

b.a cold shut.

Question 298

141. The ratio between the wave speed in one material and the wave speed in a second material is called:
     a.the acoustic impedance of the interface.
     b.Young’s modulus.
     c.Poisson’s ratio.
     d.refractive index. A.564

Answer 298

d.refractive index.

Question 299

142. The expansion and contraction of a magnetic material under the influence of a changing magnetic field is referred to as:
     a.piezoelectricity.
     b.refraction.
     c.magnetostriction.
     d.rarefaction.

Answer 299

c.magnetostriction.

Question 300

143. The ratio of stress to strain in a material within the elastic limit is called:
     a.Young’s modulus.
     b.the impedance ratio.
     c.Poisson’s ratio.
     d.refractive index

Answer 300

a.Young’s modulus.

Question 301

144. When setting up for an ultrasonic inspection, the pulse repetition rate of the instrument must be:
     a.low enough so that transmitted waves will not interfere with reflected signals.
     b.immaterial as the pulse repetition rate does not affect the ability to detect indications regardless o fsize.
     c.slow enough to allow the instrument display to refresh with each pulse.
     d.fast enough for the operator to be able to rely on the discontinuity alarm instead of constantly watching the screen. A.187

Answer 301

a. low enough so that transmitted waves will not interfere with reflected signals.

Question 302

145. The factor that determines the amount of reflection at the interface of two dissimilar materials is:
     a.the index of rarefaction.
     b.the frequency of the ultrasonic wave.
     c.Young’s modulus.
     d.the acoustic impedance.

Answer 302

d.the acoustic impedance

Question 303

146. A quartz crystal cut so that its major faces are parallel to the Z and Y axes and perpendicular to the X axis is called:
     a.a Y-cut crystal.
     b.an X-cut crystal.
     c.a Z-cut crystal.
     d.a ZY-cut crystal. A.558

Answer 303

b.an X-cut crystal.

Question 304

147. The equation describing wavelength in terms of velocity and frequency is:
     a.wavelength = velocity × frequency.
     b.wavelength = z (frequency × velocity).
     c.wavelength = velocity ÷ frequency.
     d.wavelength = frequency + velocity.

Answer 304

c.wavelength = velocity ÷ frequency.

Question 305

148. When an ultrasonic beam reaches the interface of two dissimilar materials, it can be:
     a.100% reflected.
     b.100% absorbed.
     c.partially reflected and refracted, but not absorbed.
     d.partially reflected, refracted, and transmitted.

Answer 305

d.partially reflected, refracted, and transmitted.

Question 306

149. When inspecting aluminum by the immersion method using water for a couplant, the following information is known: velocity of sound in water = 1.49 × 105 cm/s,velocity of longitudinal waves in aluminum =
     6.32 × 105 cm/s, and angle of incidence = 5°.The angle of refraction for longitudinal waves is approximately:
     a.22°
     b.18°
     c.26°
     d.16°

Answer 306

a.22°

Question 307

150. Of the piezoelectric materials listed below, the most efficient sound transmitter is:
     a.lithium sulfate.
     b.quartz.
     c.barium titanate.
     d.silver oxide. B.46 F255

Answer 307

c.barium titanate.

Question 308

151. Of the piezoelectric materials listed below, the most efficient sound receiver is:
     a.lithium sulfate.
     b.quartz.
     c.barium titanate.
     d.silver oxide. F255

Answer 308

a.lithium sulfate.

Question 309

152. The most commonly used method of producing shear waves in a test part when inspecting by the immersion method is by:
     a. transmitting longitudinal waves into a part in a direction perpendicular to its front surface.
     b.using two crystals vibrating at differentfrequencies.
     c.using a Y-cut quartz crystal.
     d.angulating the search tube to the proper angle.

Answer 309

d.angulating the search tube to the proper angle.

Question 310

153. Beam divergence is a function of the dimensions of the crystal and the wavelength of the beam transmitted through a medium, and it:
     a.increases if the frequency or crystal diameter decreases.
     b.decreases if the frequency or crystal diameter decreases.
     c.increases if the frequency increases and crystal diameter decreases.
     d.decreases if the frequency increases and crystal diameter decreases.

Answer 310

a.increases if the frequency or crystal diameter decreases.

Question 311

154. The wavelength of an ultrasonic wave is:
     a.directly proportional to velocity and frequency.
     b.directly proportional to velocity and inversely proportional to frequency.
     c.inversely proportional to velocity and directly proportional to frequency.
     d.equal to the product of velocity and frequency.

Answer 311

b.directly proportional to velocity and inversely proportional to frequency.

Question 312

155. The fundamental frequency of a piezoelectric crystal is primarily a function of the:
     a.length of the applied voltage pulse.
     b.amplifying characteristics of the pulse amplifier in the instrument.
     c.thickness of the crystal.
     d.material testing. B47 E223

Answer 312

c.thickness of the crystal.

Question 313

156. Acoustic velocities of materials are primarily due to the material’s:
     a.density and elasticity.
     b.material thickness.
     c.temperature.
     d.acoustic impedance.

Answer 313

a.density and elasticity.

Question 314

157. Inspection of castings is often impractical because of:
     a.extremely small grain structure.
     b.coarse grain structure.
     c.uniform flow lines.
     d.uniform velocity of sound.

Answer 314

b.coarse grain structure.

Question 315

158.Lamb waves may be used to inspect:
a.forgings.
b.bar stock.
c.ingots.
d.thin sheet.

Answer 315

d.thin sheet.

Question 316

159. The formula used to determine the angle of beam divergence of a quartz crystal is:
     a.sin θ = diameter r 1/2 × wavelength.
     b.sin θ diameter = frequency × wavelength.
     c.sin θ = frequency × wavelength.
     d.sin θ/2 = 1.22 × wavelength/diameter.

Answer 316

d.sin θ/2 = 1.22 × wavelength/diameter.

Question 317

160. The resolving power of a transducer is directly proportional to its:
     a.diameter.
     b.bandwidth.
     c.pulse repetition.
     d.Poisson’s ratio. F255

Answer 317

b.bandwidth.

Question 318

161. Acoustic lens elements with which of the following permit focusing the sound energy to enter cylindrical surfaces normally or along a line focus?
     a.Cylindrical curvatures.
     b.Spherical lens curvatures.
     c.Convex shapes.
     d.Concave shapes. F259

Answer 318

a.Cylindrical curvatures.

Question 319

162. In the basic pulse echo instrument, the synchronizer,clock or timer circuit determines the:
     a.pulse length.
     b.gain.
     c.pulse repetition rate.
     d.sweep length

Answer 319

c.pulse repetition rate.

Question 320

163. The primary requirement of a paintbrush transducer is that:
     a.all crystals be mounted equidistant from each other.
     b.the intensity of the beam pattern not vary greatly over the entire length of the transducer.
     c.the fundamental frequency of the crystals not vary more than 0.01%.
     d.the overall length not exceed 76 mm (3 in.). F258

Answer 320

b.the intensity of the beam pattern not vary greatly over the entire length of the transducer.

Question 321

164. Heat conduction, viscous friction, elastic hysteresis, and scattering are four different mechanisms that lead to:
     a.attenuation.
     b.refraction.
     c.beam spreading.
     d.saturation.

Answer 321

a.attenuation.

Question 322

165. Because the velocity of sound in aluminum is approximately 245 000 in./s, for sound to travel through 25 mm (1 in.) of aluminum, it takes:
     a.1/8 s
     b.4 μs
     c.4 ms
     d.1/4 ×104 s F233

Answer 322

b.4 μs

Question 323

166. When testing a part with a rough surface, it is generally advisable to use a:
     a.lower frequency transducer and a more viscous couplant than is used on parts with a smooth surface.
     b.higher frequency transducer and a more viscous couplant than is used on parts with a smooth surface.
     c.higher frequency transducer and a less viscous couplant than is used on parts with a smoothsurface.
     d.lower frequency transducer and a less viscous couplant than is used on parts with a smooth surface. B62

Answer 323

a.lower frequency transducer and a more viscous couplant than is used on parts with a smooth surface.

Question 324

167. Reflection indications from a weld area being inspected by the angle beam technique may represent:
     a.porosity.
     b.backwall.
     c.initial pulse.
     d.hot tears. B134.142.

Answer 324

a.porosity.

Question 325

168. During a test using A-scan equipment, strong indications that move at varying rates across the screen in the horizontal direction appear. It is impossible to repeat a particular screen pattern by scanning the same area. A possible cause of thes eindications is:
     a.porosity in the test part.
     b.an irregularly shaped crack.
     c.a blowhole.
     d.electrical interference. F246

Answer 325

d.electrical interference.

Question 326

169. In an A-scan presentation, position along the horizontal baseline indicates:
     a.a square wave pattern.
     b.a sweep line.
     c.a marker pattern.
     d.elapsed time. B26

Answer 326

d.elapsed time.

Question 327

170. The greatest amount of attenuation losses take place at:
     a.1 MHz
     b.2.25 MHz
     c.5 MHz
     d.10 MHz

Answer 327

d.10 MHz

Question 328

171. Waves that travel around gradual curves with little or no reflection from the curve are called:
     a.transverse waves.
     b.surface waves.
     c.shear waves.
     d.longitudinal waves. B12.13

Answer 328

b.surface waves.

Question 329

172. To evaluate and accurately locate discontinuities after scanning a part with a paintbrush transducer, it is generally necessary to use a:
     a.transducer with a smaller crystal.
     b.scrubber.
     c.grid map.
     d.crystal collimator

Answer 329

a.transducer with a smaller crystal.

Question 330

173. An ultrasonic instrument has been calibrated to obtain an 80% FSH indication from a 2mm (0.08 in.) diameter flat-bottom hole located 76 mm (3 in.) from the front surface of an aluminum reference block.When testing an aluminum forging, an 80% FSH indication is obtained from a discontinuity located 76 mm (3 in.) from the entry surface. The reflective area of this discontinuity is probably:
     a.the same as the area of the 2 mm (0.08 in.) flat-bottom hole.
     b.greater than the area of the 2 mm (0.08 in.)flat-bottom hole.
     c.slightly less than the area of the 2 mm (0.08 in.)flat-bottom hole.
     d.about one-half the area of the 2 mm (0.08 in.)flat-bottom hole. F.262

Answer 330

b.greater than the area of the 2 mm (0.08 in.)flat-bottom hole.

Question 331

174. As the impedance ratio of two dissimilar materials increases, the percentage of sound coupled through an interface of such materials:
     a.decreases.
     b.increases.
     c.is not changed.
     d.may increase or decrease. F.234

Answer 331

a.decreases.

Question 332

175. Lower frequency sound waves are not generally used for pulse echo testing of thinner materials because of:
     a.the rapid attenuation of low frequency sound.
     b.incompatible wavelengths.
     c.poor near-surface resolution.
     d.fraunhofer field effects.

Answer 332

c.poor near-surface resolution.

Question 333

176. In immersion testing, the accessory equipment to which the search cable and the transducer are attached is called a:
     a.crystal collimator.
     b.scrubber.
     c.jet-stream unit.
     d.search tube or scanning tube.

Answer 333

d.search tube or scanning tube.

Question 334

177. In general, discontinuities in wrought products tend to be oriented:
     a.randomly.
     b.in the direction of grain flow.
     c.at right angles to the entry surface.
     d.at right angles to the grain flow.

Answer 334

b.in the direction of grain flow.

Question 335

178. In immersion testing of round bars, the back surface contour may result in:
     a.loss of back reflection.
     b.additional indications following the direct back surface reflection.
     c.inability to distinguish the actual distance to theback-surface reflection.
     d.false indications of discontinuities near the backsurface. A.275 277.278

Answer 335

a.loss of back reflection.

Question 336

179. In contact testing, discontinuities near the entry surface cannot always be detected because of:
     a.the far-field effect.
     b.attenuation.
     c.the dead zone.
     d.refraction.

Answer 336

c.the dead zone.

Question 337

180. In cases where the diameter of tubing being inspected is smaller than the diameter of the transducer, what can be used to confine the sound beam to the proper range of angles?
     a.A scrubber.
     b.A collimator.
     c.An angle plane angulator.
     d.A jet-stream unit. A290-291

Answer 337

b.A collimator.

Question 338

181. Which of the following is more likely to limit the maximum scanning speed in immersion testing?
     a.The frequency of the transducer.
     b.Viscous drag problems.
     c.The pulse repetition rate of the test instrument.
     d.The persistency of the ultrasonic instrument display. A 403

Answer 338

c.The pulse repetition rate of the test instrument

Question 339

183. Surface waves energy levels are concentrated at what depth below the surface?
     a.25 mm (1 in.).
     b.102 mm (4 in.).
     c.1 wavelength.
     d.4 wavelengths.

Answer 339

c.1 wavelength.

Question 339

182. The property of certain materials to transform electrical energy to mechanical energy and vice versa is called:
     a.mode conversion.
     b.piezoelectric effect.
     c.refraction.
     d.impedance matching

Answer 339

b.piezoelectric effect.

Question 340

184. To prevent the appearance of the second front surface indication before the first back reflection when inspecting aluminum by the immersion method(water is used as a couplant), it is necessary to have a minimum of at least 25 mm (1 in.) of —————water for every of aluminum.
     a.51 mm (2 in.)
     b.102 mm (4 in.)
     c.152 mm (6 in.)
     d.203 mm (8 in.)

Answer 340

b.102 mm (4 in.)

Question 341

185. Increasing the length of the pulse used to activate the transducer will:
     a.increase the strength of the ultrasound but decrease the resolving power of the instrument.
     b.increase the resolving power of the instrument.
     c.have no effect on the test.
     d.decrease the penetration of the sound wave.
     B

Answer 341

a.increase the strength of the ultrasound but decrease the resolving power of the instrument.

Question 342

186. The lack of parallelism between the entry surface and the back surface:
     a.may result in a screen pattern that does not contain back reflection indications.
     b.makes it difficult to locate discontinuities that lie parallel to the entry surface.
     c.usually indicates that a porous condition exists in the metal.
     d.decreases the penetrating power of the test.

Answer 342

a.may result in a screen pattern that does not contain back reflection indications.

Question 343

187. A discontinuity with a concave surface will:
     a.diffuse the sound energy throughout the part.
     b.cause the reflected beam to focus at a point determined by the curvature of the discontinuity.
     c.cause mode reinforcement of the ultrasonic wave.
     d.propagate due to sound energy. B140

Answer 343

b.cause the reflected beam to focus at a point determined by the

Question 344

188. Rayleigh waves:
     a.are generated at the first critical angle.
     b.are generated at the second critical angle.
     c.are generated at either critical angle.
     d.travel only in a liquid.

Answer 344

b.are generated at the second critical angle.

Question 345

189. Angle beam testing of plate will often miss:
     a.cracks that are perpendicular to the sound wave.
     b.inclusions that are randomly oriented.
     c.laminations that are parallel to the front surface.
     d.a series of small discontinuities. F.270

Answer 345

c.laminations that are parallel to the front surface.

Question 346

190. Reducing the extent of the dead zone of a transducer by using a delay tip results in:
     a.improved distance-amplitude correction in the near field.
     b.reduced frequency of the primary ultrasonic beam.
     c.reduced ability to detect discontinuities in the near field.
     d.improved accuracy in thickness measurement of thin plate and sheet.

Answer 346

d.improved accuracy in thickness measurement of thin plate and sheet.

Question 347

191. In a plate, skip distance can be calculated from which of the following formulas where (t = plate thickness,θ = angle of sound beam refraction, and V = soundvelocity):
     a.S = (2 × t)/tan θ.
     b.S = 2 × t × sin θ.
     c.S = 2 × t × tan θ.
     d.S = 2 ×V × sin θ.
     F.266

Answer 347

c. S=2×t×tanθ.

Question 348

192. The technique of examining an ultrasonic reflector from different directions might be used to enable the technician to:
     a.distinguish between different types of discontinuities.
     b.predict the useful service life of the test specimen.
     c.distinguish between discontinuity indications and spurious or false indications.
     d.accept an indication that appeared to be rejectable from the first test direction. F247

Answer 348

a.distinguish between different types of discontinuities.

Question 349

193. Attenuation is the loss of the ultrasonic wave energy during the course of propagation in the material due to:
     a.reflection and refraction.
     b.dispersion and diffraction.
     c.absorption and scattering.
     d.composition and shape

Answer 349

c.absorption and scattering.

Question 350

194. In immersion shear wave testing, waves are normally generated by angulating the transducer beyond the first critical angle. What is the direction of the material’s particle motion?
     a.The same as the wave propagation.
     b.Normal to the material surface.
     c.Parallel to the direction of wave propagation.
     d.Perpendicular to the direction of wave propagation.

Answer 350

d.Perpendicular to the direction of wave propagation.

Question 351

195. Which of the following modes of vibration arequickly dampened out when testing by the immersion method?
     a.Longitudinal waves.
     b.Shear waves.
     c.Transverse waves.
     d.Surface waves.

Answer 351

d.Surface waves.

Question 352

196. Which ultrasonic test frequency would probably provide the best penetration in a 30 cm (12 in.) thick specimen of coarse-grained steel?
     a.1 MHz
     b.2.25 MHz
     c.5 MHz
     d.10 MHz

Answer 352

a.1 MHz

Question 353

197. A quartz crystal cut so that its major faces are parallel to the Z and Y axes and perpendicular to the X axis is called:
     a.a Y-cut crystal.
     b.an X-cut crystal.
     c.a Z-cut crystal.
     d.a ZY-cut crystal.

Answer 353

a.a Y-cut crystal.
b.an X-cut crystal.