L2:P6

Question 1

1)

Of the following sound wave modes, which one has multiple or varying wave velocities?

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

Answer 1

d. lamb waves

Question 2

2)

Which of the following would be considered applications of ultrasonic techniques:

a. determ,ination of a flaw depth
b. study of a materials metallurgical structure
c. measurement of a materials thickness
d. all of the above

Answer 2

d. all of the above

Question 3

3)

The only significant sound wave mode rhat will travel through a liquid is:

a. shear
b. longitudinal
c. surface
d. rayleigh

Answer 3

b. longitudinal

Question 4

4)

The acoustic impedance of a material is used to:

a. determine the angle of refraction at an interface
b. determine the attentuation within the material
c. determine the relative amounts of sound energy transmitted across and reflected at an interface

Answer 4

c. determine the relative amounts of sound energy transmitted across and reflected at an interface

Question 5

5)

**When angle beam contact testing a test piece, increasing the incident angle until the second critical angle is reached results in:
**
a. a total reflection of a shear wave
b. 80 degree refraction of the shear wave
c. production of a surface wave
d. none of the above

Answer 5

c. production of a surface wave

Question 6

6)

Acoustic energy propagates in different modes. which of the following represent a mode:

a. longitudinal wave
b. plate wave
c. shear wave
d. all of the above

Answer 6

d. all of the above

Question 7

7)

The fact that a stick placed in a glass of water appears to bend at the water surface is due to:

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

Answer 7

c. refraction

Question 8

8)

The crystal thickness and tranducer frequency are related. the thicker the crystal:

a. the higher the frequency
b. the lower the frequency
c. there is no appreciable effect
d. none of the above

Answer 8

b. the lower the frequency

Question 9

9)

A large grain structure will affect which of the following:

a. acoustic noise levels
b. selection of test frequency
c. scattering if sound energy
d. none of the above

Answer 9

d. none of the above

Question 10

10)

The length of the near zone is affected by:

a. the frequency of the transducer
b the diameter of the transducer
c. gain control settings
d. both a and b
e. all of the above

Answer 10

d. both a and b

Question 11

11)

The differences in signals receieved from identical reflectors at different material distances may be caused by:

a. material attenuation
b. beam divergence
c. near field effects
d. all of the above

Answer 11

d. all of the above

Question 12

12)

It is possible for a discontinuity smaller than the transducer to produce indications of fluctuating amplitude in the:

a. dead zone
b. near zone
c. far frield
d. all of the above

Answer 12

b. near zone

Question 13

13)

Diagram question

Answer 13

Refer to paper

Question 14

14)

Where does beam divergence occur:

a. near field
b. far field
c. at the crystal
d. none of the above

Answer 14

b. far field

Question 15

15)

As frequency decreases in ultrasonic testing, the angle of beam divergence of a given diameter crystal:

a. increases
b. varies uniformly through each wavelength
c. decreases
d. remains unchanged

Answer 15

a. increases

Question 16

16)

Under normal test conditions, when examining material for planar flaws oriented paralell to the part surface, what testing method is best used:

a. dual crystal
b. angle beam
c. straight beam
d. through-transmission

Answer 16

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Question 17

17)

**If a contact angle beam transducer produces a 60 degree shear wave in steel, the angle produced by the same transducer in an aluminium specimen would be: (VSsteel = 3.2 mm/s; Vsai = 3.1 mm/s):
**
a. less than 60 degrees
b. greater than 60 degrees
c. 60 degrees
d. more imformation is required

Answer 17

a. less than 60 degrees

Question 18

18)

Rayleigh waves are influenced most be defects located:

a. two wavelengths below the surface
b. three wavelengths below the surface
c. close to or on the surface
d. six wavelengths below the surface

Answer 18

c. close to or on the surface

Question 19

19)

Finger damping is most effective in locating a discontinuity when using:

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

Answer 19

c. surface wave

Question 20

20)

Lamb waves can be used to detect:

a. laminar-type defects near the surface of a thin material
b. lack of fusion on a weld side wall
c. internal voids in castings
d. thickness variations in heavy plate metal

Answer 20

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

Question 21

21)

A decrease in ultrasonic attenuation will occur when a specimen is examined consecutively using probes with:

a. higher damping
b. a narrower beam
c. a shorter pulse duration
d. lower frequency

Answer 21

d. lower frequency

Question 22

22)

The echo amplitude from a flaw can be used to determine its:

a. exact size
b. depth
c. through wall extent
d. none of the above

Answer 22

d. none of the above

Question 23

23)

An exponential decrease in echo amplitude will take place when:

a. a side drilled hole is used instead of a flat-bottomed hole
b. the surface area of the reflector decreases
c. the voltage is decreased
d. when sizing the near field

Answer 23

b. the surface area of the reflector decreases

Question 24

24)

Which of the following statements is true?

a. to obtain maximum reflection the flaw should be normal to the ultrasonic energy
b. castings generally have higher attenuation than forged products
c. compression and angle probes are used to examine welds
d. all of the above

Answer 24

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Question 25

# **25)** **The K constant used to determine the theoretical 20dB drop beam spread is:** a. 0.56 b. 1.08 c. 1.18 d. 1.22

Answer 25

b. 1.08

Question 26

# **26)** **A sizeable lengthening of the transmitter pulse may be a consequence of:** a. a damaged pribe b. the detachment of the damping/backing material c. heavy damping d. both a and b

Answer 26

d. both a and b

Question 27

# **27)** **The disc shaped or flat-bottomed hole reflector is used to obtain the:** a. a damaged probe b. the detachment of the damping/backing material c. heavy damping d. both a and b

Question 28

# **28)** **A flaw detector feature that requires the operator to adjust the time base range and discontinuity amplitude level is known as:** a. the reject control b. the attenuator c. a gate d. the distance amplitude control

Answer 28

c. a gate

Question 29

# **29)** **When the incident energy neets an interface, the reflected energy will be greater than the transmitted energy in which case:** a. Z is the same for both mediums b. Z is significangtly different between both mediums c. Z ratio is 2:1 d. Z ratio is 5:1

Answer 29

b. Z is significangtly different between both mediums

Question 30

# **30)** **A probe with an acoustic lens attachment could be used to:** a. increase sensitivity and resolution b. create a high intensity focussing beam c. decrease the reverberation of sound on a rough surface d. all the above are correct

Answer 30

d. all the above are correct

Question 31

# **31)** **When manufacturing a reference block with side drilled holes, the holes should be:** a. wider than the sound beam and paralell to the scan surface b. narrower than the sound beam and perpendicular to the scan surface c. at the same angle as the probe being used d. at any angle, provided they have a width less than the sound beam

Answer 31

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Question 32

# **32)** **The most accurate measurement of an angle probes beam angle is achieved by using:** a. the 50mm diameter hole in the no.1 calibration block b. a side drilled hole at half the test piece thickness c. the side drilled holes at various depths in the A6 block d. snells law

Answer 32

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Question 33

# **33)** **What is the diameter ratio between two flat bottomed holes at the same metal path when their amplitudes differ by 12dB:** a. the diameter ratio cannot be determined from the information given b. 3:1 c. 4:1 d. 2:1

Answer 33

d. 2:1

Question 34

# **34)** **A heavily damped probe will produce:** a. lower resolution b. a wide/broad bandwidth c. a narrow bandwidth d. higher amplitude pulses

Answer 34

b. a wide/broad bandwidth

Question 35

# **35)** **Which type of reference block can be used to construct a DAC curve, set sensitivity, and measure the beam angle of transverse wave probes:** a. one containing disc shaped reflectors b. one containing notches c. one containing side drilled holes d. no such block exists

Answer 35

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Question 36

# **36)** **What could be the cause of non-relevant signals on an A-scan display:** a. a defect b. mode conversion c. electrical interference d. both b and c could be causes

Answer 36

d. both b and c could be causes

Question 37

# **37)** **Interference causes sound pressure variations in whicharea of the ultrasonic beam:** a. far field b. fresnel zone c. fraunhofer zone d. both a and c are correct

Answer 37

b. fresnel zone

Question 38

# **38)** **For which sizing technique must the defect be smaller than the sound beam diameter, and the test specimens acoustic impedance be the same as the reference block?** a. equivelant flat-bottomen hole b. equivelant side drilled hole c. 20dB drop d. 6dB drop

Answer 38

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Question 39

# **39)** **What action would you take is a discontinuities signal is below the DAC evaluation level:** a. ignore it and continue with the test b. ask a colleague what to do c. size and record it d. increase the test sensitivity

Answer 39

a. ignore it and continue with the test

Question 40

# **40)** **The operating frequency of an ultrasonic probe is affected by the thickness of the crystal, the damping material on the crystal, the elctrics connected to the probe, and is defined as:** a. the number of pulses per wave b. the number of pulses a probe produces per unit of time c. the dominant frequency of the probes vibration range d. the tests range of frequencies

Answer 40

c. the dominant frequency of the probes vibration range