UT SG Flashcards
1
Q
- Ultrasonic waves propagate through test materials in the form of:
a. electromagnetic waves.
b. low-voltage electric fields.
c. discontinuous radio waves.
d. mechanical vibrations.
A
d. mechanical vibrations
2
Q
- When an ultrasonic beam passes through the interface of two dissimilar materials at an angle, a new angle of sound travel takes place in the second material due to:
a. refraction.
b. attenuation.
c. rarefaction.
d. compression.
A
a. refraction.
3
Q
- The gradual loss of energy as ultrasonic vibrations travel through material is referred to as:
a. reflection.
b. refraction.
c. compression.
d. attenuation.
A
d. attenuation.
4
Q
- Ultrasonic velocities are different for different materials. These differences are primarily caused by differences in the materials’:
a. frequency and wavelength.
b. thickness and travel time.
c. elasticity and density.
d. chemistry and permeability
A
c. elasticity and density.
5
Q
- Ultrasonic energy for immersion testing is transmitted to the test object as a compressional wave because:
a. compressional waves travel faster and will therefore reduce the distance of the interface signal.
b. liquids will only sustain compressional waves.
c. compressional waves are used with immersion
testing only.
d. the higher intensity of compressional waves is
necessary to overcome high attenuation in liquids.
A
b. liquids will only sustain compressional waves.
6
Q
- When inspecting coarse-grained materials, which of the following frequencies will generate a sound wave that will be most easily scattered by the grain structure?
a. 1.0 MHz
b. 2.25 MHz
c. 5 MHz
d. 10 MHz
A
d. 10 MHz
7
Q
- 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 the
wavelength 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 the
wavelength of longitudinal waves.
A
a. the wavelength of shear waves is shorter than the
wavelength of longitudinal waves.
8
Q
- The ability of transducers to detect echoes from small discontinuities is a definition of:
a. resolution.
b. sensitivity.
c. definition.
d. gain.
A
b. sensitivity.
9
Q
- Which of the following will create a resonance condition in a specimen?
a. Continuous longitudinal waves.
b. Pulsed longitudinal waves.
c. Pulsed shear waves.
d. Continuous shear waves.
A
a. Continuous longitudinal waves.
10
Q
- The display on most basic pulse-echo ultrasonic
instruments consists of:
a. automatic read-out equipment.
b. an A-scan presentation.
c. a B-scan presentation.
d. a C-scan presentation.
A
b. an A-scan presentation.
11
Q
- In a basic pulse-echo ultrasonic instrument, the
component that produces the voltage that activates the search unit is called:
a. an amplifier.
b. a receiver.
c. a pulser.
d. a synchronizer.
A
c. a pulser.
12
Q
- 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. provide a known reflecting area in calibrating an
instrument.
d. establish the size and orientation of a discontinuity.
A
c. provide a known reflecting area in calibrating an
instrument.
13
Q
- The general use of distance-amplitude correction is to compensate for:
a. attenuation, distance, and beam spread.
b. amplitude of noise signals.
c. velocity changes.
d. vertical nonlinearity in the ultrasonic instrument.
A
a. attenuation, distance, and beam spread.
14
Q
- In area-amplitude ultrasonic standard test blocks, the flatbottom holes in the blocks are:
a. all the same diameter.
b. different in diameter, increasing in size of 1/64 in.
(0.0156 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.
A
b. different in diameter, increasing in size of 1/64 in.
(0.0156 in.) increments from the No. 1 block to the
No. 8 block.
15
Q
- Which of the following factors has the least influence on the amount of energy reflected from a discontinuity?
a. Size of the discontinuity.
b. Orientation of the discontinuity.
c. Discontinuity type.
d. Test frequency.
A
d. Test frequency.
16
Q
- The ability to locate discontinuities that are close together within the material is called:
a. resolution.
b. sensitivity.
c. effectiveness.
d. phase delay.
A
a. resolution.
17
Q
- 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 a porous condition existing in the
metal.
d. will decrease the penetrating power of the test.
A
a. may result in a screen pattern that does not contain
back reflection indications.
18
Q
- Significant errors in ultrasonic thickness measurement can occur if:
a. test velocity is kept constant.
b. the velocity of propagation deviates substantially
from an assumed constant value for a given material.
c. water is used as a couplant between the transducer
and the part being measured.
d. longitudinal waves are used.
A
b. the velocity of propagation deviates substantially
from an assumed constant value for a given material.
19
Q
- In contact testing, shear waves can be induced in the test material by:
a. placing an X-cut quartz crystal directly on the surface of the material and coupling through a film of oil.
b. using two transducers on opposite sides of the test
specimen.
c. using an angle-beam transducer with the transducer mounted on a plastic wedge so that sound enters the part at an angle.
d placing a spherical acoustic lens on the face of the
transducer.
A
c. using an angle-beam transducer with the transducer mounted on a plastic wedge so that sound enters the part at an angle.
20
Q
- 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 different frequencies.
c. using a low-frequency transducer.
d. angulating the transducer to the proper angle with
respect to the entry surface of the test part
A
d. angulating the transducer to the proper angle with
respect to the entry surface of the test part
21
Q
- In immersion testing, proof that the search unit is normal (perpendicular) to a flat entry surface is indicated by:
a. maximum reflection amplitude from the entry
surface.
b. elimination of water multiples.
c. maximum reflection amplitude from the back
surface.
d. maximum amplitude of the initial pulse.
A
a. maximum reflection amplitude from the entry
surface.
22
Q
- In immersion testing, the water distance between the search unit and the test piece:
a. should be as small as possible.
b. will have no effect on the test.
c. should be the same as the water distance used during calibration.
d. should be as great as possible.
A
c. should be the same as the water distance used during calibration.
23
Q
- Generally, the best UT technique for detecting
discontinuities oriented along the fusion zone in a welded plate is:
a. an angle-beam contact method employing surface
waves.
b. an immersion test using surface waves.
c. a resonance technique.
d. an angle-beam method using shear waves.
A
d. an angle-beam method using shear waves.
24
Q
- Thin sheet may be inspected for laminar discontinuities with the ultrasonic wave directed normal (perpendicular) to the surface by observing:
a. the amplitude of the front surface reflection.
b. the multiple reflection pattern.
c. the amplitude of the initial pulse.
d. signals that “walk” or move along the time base as the transducer is scanned over the sheet.
A
b. the multiple reflection pattern.
25
Q
- Ultrasonic inspection of castings is occasionally
impractical because of:
a. extremely small grain structure typical in castings.
b. coarse grain structure.
c. uniform flow lines.
d. random orientation of discontinuities
A
b. coarse grain structure
26
Q
- 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.
A
c. laminations that are parallel to the front surface.
27
Q
- In addition to a weld area being inspected by the angle beam technique, which additional test is typically performed to detect laminations in the base metal?
a. Through-transmission testing.
b. Guided wave testing.
c. Straight-beam testing.
d. Surface-wave testing.
A
c. Straight-beam testing.
28
Q
- An ultrasonic test using a straight-beam contact search unit is being conducted through the thickness of a flat part, such as plate. This test should detect:
a. laminar-type discontinuities with major dimensions
parallel to the plane of the rolled surface.
b. transverse-type discontinuities with major
dimensions at right angles to the plane of the rolled
surface.
c. radial discontinuities with major dimensions along
the length but radially oriented to the rolled surface.
d. rounded discontinuities at the edges of the rolled
plate.
A
a. laminar-type discontinuities with major dimensions
parallel to the plane of the rolled surface.
29
Q
- UT techniques are useful in testing laminate and
sandwich construction test objects for:
a. paint thickness.
b. bond integrity.
c. leakage.
d. surface roughness.
A
b. bond integrity.
30
Q
- UT techniques are frequently used in online automatic process control applications to measure and control:
a. moisture content in materials.
b. surface roughness of turbine blade castings.
c. the thickness of cold-rolled strips, sheets, and plates.
d. chemical activity in chemical etching processes.
A
c. the thickness of cold-rolled strips, sheets, and plates.
31
Q
- Which of the following statements about field inspection applications of UT is true?
a. Manual and automatic systems can be used for field
inspections.
b. Because the equipment is large and bulky, field
inspections are difficult, at best.
c. Aircraft and other field maintenance inspections
usually require three persons: one to manipulate the
transducer, one to monitor the instrument, and one
to record results.
d. Digital displays must be used for outdoor inspection because of the limited brightness of screen displays.
A
a. Manual and automatic systems can be used for field
inspections.
32
Q
- Which of the following waves is able to follow a surface around a curve?
a. Longitudinal wave.
b. Shear wave.
c. Surface wave.
d. Lamb wave.
A
d. Lamb wave.
