Ultrasonic Testing (UT) Review Questions

Question 1

1. 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

Answer 1

D. Mechanical vibrations

Question 2

2. 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. Attenuation 
B. Rarefraction 
C. Compression 
D. Refraction

Answer 2

D. Refraction

Question 3

3. The gradual loss of energy as ultrasonic vibrations travel through material is referred to as:
A. Reflection 
B. Refraction 
C. Compression 
D. Attenuation

Answer 3

D. Attenuation

Question 4

4. 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

Answer 4

C. Elasticity and density

Question 5

5. 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

Answer 5

B. Liquids will only sustain compressional waves

Question 6

6. When inspecting corse-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

Answer 6

D. 10 MHz

Question 7

7. 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 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

Answer 7

A. The wavelength of shear waves is shorter than the wavelength of longitudinal waves

Question 8

8. The ability of transducers to detect echoes from small discontinuities is a definition of?
A. Resolution 
B. Sensitivity
C. Definition 
D. Gain

Answer 8

B. Sensitivity

Question 9

9. Which of the following will create a resonance condition in a specimen?
A. Pulsed longitudinal waves
B. Continuous longitudinal waves
C. Pulsed shear waves
D. Continuous shear waves

Answer 9

B. Continuous longitudinal waves

Question 10

10. 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

Answer 10

B. An A-scan presentation

Question 11

11. 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

Answer 11

C. A pulser

Question 12

12. 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 reference standard
    D. Establish the size and orientation of a discontinuity

Answer 12

C. Obtain a common reproducible reference standard

Question 13

13. The general use of distance-amplitude correction is to compensate for:
    A. Amplitude of noise siganls
    B. Velocity changes
    C. Vertical nonlinearity in the ultrasonic instrument
    D. Attenuation, distance and beam spread

Answer 13

D. Attenuation, distance and beam spread

Question 14

14. In area-amplitude ultrasonic standard test blocks, the flat bottomed holes in the blocks are:
    A. All the same diameter
    B. Different in diameter, increasing in 0.4 mm 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 14

B. Different in diameter, increasing in 0.4 mm increments from the No. 1 block to the No. 8 block

Question 15

15. The amount of energy reflected from a discontinuity is dependent on all the following except the:
A. Size of the discontinuity
B. Orientation of the discontinuity 
C. Type of the discontinuity
D. Test frequency

Answer 15

D. Test frequency

Question 16

16. The presence of a discontinuity will not produce a specific discontinuity indication on the CRT screen when which of the following techniques is used?
A. Straight-beam testing
B. Surface-wave testing
C. Angle-beam testing
D. Through-transmission testing

Answer 16

D. Through-transmission testing

Question 17

17. 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

Answer 17

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

Question 18

18. Significant errors in ultrasonic thickness measurement can occur if:
    A. Test velocity is varied
    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

Answer 18

B. The velocity of propagation deviates substantially from an assumed constant value for a given material

Question 19

19. 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. Placing a spherical acoustic lens on the face of the transducer
    D. Using an angle-beam transducer with the transducer mounted on a plastic wedge so that sound enters the part at an angle

Answer 19

D. Using an angle-beam transducer with the transducer mounted on a plastic wedge so that sound enters the part at an angle

Question 20

20. 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 search tube to the proper angle with respect to the entry surface of the test part

Answer 20

D. Angulating the search tube to the proper angle with respect to the entry surface of the test part

Question 21

21. In immersion testing, proof that the search unit is normal 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

Answer 21

A. Maximum reflection amplitude from the entry surface

Question 22

22. 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

Answer 22

C. Should be the same as the water distance used during calibration

Question 23

23. Generally, the best ultrasonic testing technique for detecting discontinuities oriented along the fusion zone is 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

Answer 23

D. An angle-beam method using shear waves

Question 24

24. Thin sheet may be inspected for laminar discontinuities with the ultrasonic wave directed normal 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 basis as the transducer is scanned over the sheet

Answer 24

B. The multiple reflection pattern

Question 25

25. 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

Answer 25

B. Coarse grain structure

Question 26

26. Angle beam testing of plate will often miss:
    A. Cracks that are perpendicular to the sound wave
    B. Inclusions that are randomly orientated
    C. Laminations that are parallel to the front surface
    D. A series fo small discontinuities

Answer 26

C. Laminations that are parallel to the front surface

Question 27

27. Reflection indications from a weld being inspected by the angle-beam technique may represent all of the following except:
A. Porosity
B. Cracks
C. The weld bead
D. Laminations in the base metal

Answer 27

D. Laminations in the base metal

Question 28

28. 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 flaws with major dimensions parallel to the plane of the rolled surface
    B. Transverse type flaws with major dimensions at right angles to the plane of the rolled surface
    C. Radial flaws with major dimensions along the length but radially oriented to the rolled surface
    D. Rounded flaws at the edges of the rolled plate

Answer 28

A. Laminar type flaws with major dimensions parallel to the plane of the rolled surface

Question 29

29. The resonance technique of thickness measurement has been mostly replaced by:
    A. Through-transmission longitudinal wave techniques
    B. Acoustic emission monitoring
    C. Pitch-and-catch shear-wave techniques
    D. Linear time-based pulse-echo techniques

Answer 29

D. Linear time-based pulse-echo techniques

Question 30

30. Ultrasonic testing techniques are useful in testing laminate and sandwich construction test objects for:
A. Paint thickness
B. Bond integrity 
C. Leakage
D. Surface roughness

Answer 30

B. Bond integrity

Question 31

31. Ultrasonic techniques are frequently used in in-line automated process control applications to measure and control:
    A. Moisture content in food
    B. Surface roughness of turbine blade castings
    C. Chemical activity in chemical etching processes
    D. The thickness of cold-rolled strips, sheets and plates

Answer 31

D. The thickness of cold-rolled strips, sheets and plates

Question 32

32. Which of the following statements about field inspection applications of ultrasonic testing is true:
    A. Because the equipment is large and bulky, field inspections are difficult at best
    B. 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
    C. Digital displays must be used for outdoor inspection because of the limited brightness of CRT displays
    D. Manual and automatic systems can be used for field inspection

Answer 32

D. Manual and automatic systems can be used for field inspection