3.2u Mock Exam 2 Flashcards

1
Q

What prevents the steal reinforcement from corroding In a concrete structure?

A

Passivation

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2
Q

Which of the following is a Volumetric defect?

A

Answer: Undercut

a. Fatigue crack
b. Lack of sidewall fusion
c. Undercut
d. Lamination

3D
Fabrication Defect

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3
Q

When using a Bathycorrometer, which of the following readings would indicate that the structure was under protected?

A

Answer: -640mV to -800mV
( Note the words “under protected” and not “unprotected”)

a. -540 to -600mV
b. -450 to -640mV
c. -800 to -1100mV
d. -640 to -800mV

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4
Q

Which NDT method can be used to size for length and depth, a surface- breaking defect?

A

ACFM

Cleaning Standard SA 2
Skin Effect
Can read through coatings up to 5mm

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5
Q

The type of corrosion that can occur beneath a water drop is?

A

Pitting Corrosion

Once Started: autocatalytic
Localized

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6
Q

Iridlium 192 Is a Gamma Radiation source used for?

A

Weld Inspection on plate up to 5Omm

Used in Radiography in plate 50-90mm
Cobalt 60 used for thicker plate
Safety Zone 8m
Cleaning Standard SA1
Volumetric Defects

The most common source used offshore is Iridium 192 that Iridium 192 can penetrate approximately 90mm of steel but is normally limited to 50mm.

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7
Q

The Cathodic reaction is also known as?

A

Reduction

Remember:
An Ox Red Cat
Anode = Oxidation = Loss of electrons
Cathode = Reduction = Gain of Electrons
Electron flow (-) to (+)

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8
Q

Assuming you have access to both sides of a weld, which of the following defects could not be found during a visual inspection?

A

Answer: Lack of inter-run fusion in a single V butt weld

a. Lack of inter-run fusion in a single V butt weld
b. Lack of root penetration in a single bevel butt weld
c. Lack of root penetration in a single V butt weld
d. Lack of sidewall fusion and incompletely filled groove

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9
Q

On a digital camera, changing the f-stop from f8 to f11 will produce which effect?

A

Half the amount of light entering the camera

Smaller aperature
Less light
Increase depth of field

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10
Q

Which of the following focal lengths will give a wider field of view?

A

Answer: 16mm

a.50mm
b.73mm
c.28mm
d.16mm

Shorter Focal Length (e.g., 18mm) - Wider Field of View

Longer Focal Length (e.g., 50mm) - Narrower Field of View

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11
Q

When welding, residual magnetism in a metal could cause which affect?

A

Arc Blow

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12
Q

Impingement is a consequence of?

A

Laminar Flow

Erosion corrosion happens when metal is worn away due to the smooth flow of liquid (laminar flow), and impingement, a consequence of this process, occurs when the liquid forcefully impacts the metal surface.

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13
Q

Plain concrete is a description of?

A

Cement, aggregates and water

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14
Q

Sea Squirts are which of the following?

A

Answer: Soft-bodied animals that grow in colonies down to 1000m

a. Hard-bodied animals that grow in colonies down to 50m
b. Plants that grow in colonies down to 20m
c. Soft-bodied animals that grow in colonies down to 1000m
d. Soft-bodied animals that grow in colonies down to 50m

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15
Q

According to Snell’s Law, what happens when sound waves meet an interface?

A

Sound waves refract at the Interface

According to Snell’s Law, when sound waves meet an interface between different media, they change direction or angle.

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16
Q

Which of the following statements 1s true?

A

Answer: Taking CP readings is not a defect detection method

a. MPI is only used to detect internal defects
b.Taking CP readings is not a defect detection method
c. Radiography is good for finding Planar defects
d. ACFM can find sub-surface defects

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17
Q

Which of these statements is true?

A

Answer: ACPD requires SA2.5

a. ACFM requires SA 2.5
b. ACPD requires SA2.5
c. Eddy Current requires SA3
d. Radiography requires SA3

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18
Q

Which of the following is an in-service defect?

A

Answer: Poor Repair

d. Tearing
c. Honeycombing
b. Blowholes
a. Poor Repair

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19
Q

Which statement, concerning welding defects, is true?

A

Answer: Poor stop start is an imperfect shape defect

a. Undercut is a planar defect
b. A crater is caused by gas being trapped in the weld pool
c. Porosity is in the Solid Inclusion category
d. Poor stop start is an imperfect shape defect

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20
Q

Using a strobe light on an arm at an angle will help prevent which effects, when taking standoff shots of an anode?

A

Backscatter

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21
Q

A device which changes electric energy into mechanical energy is called?

A

Transducer

22
Q

Monel Cladding is an alloy of which of the following two materials?

A

Copper/Nickel

23
Q

On an ICCP system, which of the following is true?

A

Answer: A reference electrode measures the potential

a. Reference electrodes are connected to the negative side of a DC generator
b. A reference electrode measures the potential
c. A reference electrode must be insulated from the electrolyte
d. A reference electrode measures the current density

ICCP:
Anode is high on Galvanic series: Platinum / titatnium
Anode conected to (+)
Structure Connected to (-)
DC current

24
Q

Which of these may be considered an advantage with sacrificial anodes?

A

Answer: They are made from a material which corrodes

a. They work in the splash zone
b. They are made from a material which corrodes
c. They are cheap to install
d. Current output decreases with time

Low on Galvanic Series: AL/Zn/Mg
CP reading on Zinc Block -1050mV

25
Q

An Ultrasonic Digital Thickness Meter can be used to‘?

A

Assess an area of thinning on a back wall of a member

26
Q

The angle of incidence is 30 Deg. What will the angle of reflection be?

A

30 Deg

27
Q

Which of the following would corrode the quickest if put in electrical contact with steel underwater?

A

Answer: Magnesium

a.Zinc
b.Lead
c.Aluminium
d.Magnesium

Magnesium is lower than Steel on the galvanic series

28
Q

In Ultrasonics, which of the following is correct?

A

Answer: A faster velocity will produce a shorter wavelength

a. A faster velocity will produce a shorter wavelength
b. A faster velocity will produce a s longer wavelength
c. A shorter wavelength will penetrate further
d. A longer wavelength will detect smaller defects

29
Q

Who appoints the IVB and when?

A

The Duty Holder at the conception of the structure

30
Q

Which of the following would produce a greater depth of field?

A

Answer: Change the f-stop from f4 to f5.6

a. Change the f-stop from f4 to f5.6
b. Move the camera closer to the subject
c. Change the focal length of the lens from 28mm to 50mm
d. Change the f-stop from f8 to f5.6

31
Q

An ICCP system may produce over protection, this is bad because

A

It may cause embrittlement

32
Q

The Near Zone of a Single Crystal ultrasonic probe Is

A

Used for lamination and thickness measurements

33
Q

The ultrasonic Through Transmission Technique is used for?

A

Answer: None of these options

Weld inspection
Finding the depth of an internal defect
Flooded member detection

34
Q

A diver carrying out FMD would use which of the following?

A

Answer: O.5MHz Ultrasonic probe

a. Iridium 192
b.Caesium 137
c.O.5MHz Ultrasonic probe
d.5MHz Ultrasonic probe

35
Q

Proximity CP meters work only if?

A

The positive side of the voltmeter is connected to the structure and a maximum 100 mm gap is maintained

The Proximity meter is connected to the
negative

The ICCP anode is connected to the positive terminal

36
Q

In an ICCP sytem where would the dielectric shield be installed

A

Between the anode and the structure

37
Q

In an ICCP system which materials are most commonly used for anodes

A

Platinum sheathed titaniun and lead/silver alloys

38
Q

A retrofit anode Is to be installed, which of the following is necessary to make it work correctly

A

Answer: A continuity bolt connecting the anode electrically to the structure

a. A bonding cable connecting the retrofit anode to a DC generator
b. Cleaning to SA3
c. A continuity bolt connecting the anode electrically to the structure
d. A bonding cable connecting the retrofit anode to the nearest existing anode

39
Q

Sound waves in air will travel further when?

A

The wavelength is longer

Explanation: The distance a sound wave can travel in a medium is determined by its wavelength and the velocity of sound in that medium. In air, the velocity of sound remains relatively constant under normal conditions. Therefore, when the wavelength is longer, the sound wave can travel further before dissipating.

40
Q

Which of the following is an advantage of a twin crystal probe over a single crystal probe?

A

Good Near Zone resolution

41
Q

Which of the following is a true statement with regards to brittle fracture

A

Answer: Brittle fracture is most likely to occur in cold environments

a.Brittle fracture is more likely to occur in warm environments
b.Brittle fracture is more likely to occur in cold environments
c.Temperature has no effect on brittle fracture
d.Brittle fracture cannot occur unless the yield point is exceeded

42
Q

Which of the following is associated with Erosion Corrosion

A

Laminar flow

43
Q

Crevice corrosion occurs because ?

A

Dissimilar oxygen concentrations

44
Q

The Pourbaix Diagram displays which of these pairs of variables?

A

Potential and pH

45
Q

AC current is more preferred for finding surface-breaking defects because?

A

The domains are agitated by the rapid change in direction

46
Q

Altering the frequency of an ultrasonic probe will affect which of the following parameters?

A

The Wavelength

47
Q

With regards to inspecting concrete structures: Variable Cover is what type
of defect?

A

A category ,construction defect

48
Q

Dynamic Loading Is based on?

A

Normal Wave and wind spectrum

49
Q

0.5 to 1.5MHz ultrasonic probes are used for testing which of the following?

A

Concrete

50
Q

Which of these techniques cannot be used to determine the depth of a surface breaking defect?

A

Eddy current

a.ACPD
b.ACFM
c.Remedial Grinding
d.Eddy Current