3.2u Mock Exam 2 Flashcards
What prevents the steal reinforcement from corroding In a concrete structure?
Passivation
Which of the following is a Volumetric defect?
Answer: Undercut
a. Fatigue crack
b. Lack of sidewall fusion
c. Undercut
d. Lamination
3D
Fabrication Defect
When using a Bathycorrometer, which of the following readings would indicate that the structure was under protected?
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
Which NDT method can be used to size for length and depth, a surface- breaking defect?
ACFM
Cleaning Standard SA 2
Skin Effect
Can read through coatings up to 5mm
The type of corrosion that can occur beneath a water drop is?
Pitting Corrosion
Once Started: autocatalytic
Localized
Iridlium 192 Is a Gamma Radiation source used for?
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.
The Cathodic reaction is also known as?
Reduction
Remember:
An Ox Red Cat
Anode = Oxidation = Loss of electrons
Cathode = Reduction = Gain of Electrons
Electron flow (-) to (+)
Assuming you have access to both sides of a weld, which of the following defects could not be found during a visual inspection?
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
On a digital camera, changing the f-stop from f8 to f11 will produce which effect?
Half the amount of light entering the camera
Smaller aperature
Less light
Increase depth of field
Which of the following focal lengths will give a wider field of view?
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
When welding, residual magnetism in a metal could cause which affect?
Arc Blow
Impingement is a consequence of?
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.
Plain concrete is a description of?
Cement, aggregates and water
Sea Squirts are which of the following?
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
According to Snell’s Law, what happens when sound waves meet an interface?
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.
Which of the following statements 1s true?
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
Which of these statements is true?
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
Which of the following is an in-service defect?
Answer: Poor Repair
d. Tearing
c. Honeycombing
b. Blowholes
a. Poor Repair
Which statement, concerning welding defects, is true?
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
Using a strobe light on an arm at an angle will help prevent which effects, when taking standoff shots of an anode?
Backscatter
A device which changes electric energy into mechanical energy is called?
Transducer
Monel Cladding is an alloy of which of the following two materials?
Copper/Nickel
On an ICCP system, which of the following is true?
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
Which of these may be considered an advantage with sacrificial anodes?
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
An Ultrasonic Digital Thickness Meter can be used to‘?
Assess an area of thinning on a back wall of a member
The angle of incidence is 30 Deg. What will the angle of reflection be?
30 Deg
Which of the following would corrode the quickest if put in electrical contact with steel underwater?
Answer: Magnesium
a.Zinc
b.Lead
c.Aluminium
d.Magnesium
Magnesium is lower than Steel on the galvanic series
In Ultrasonics, which of the following is correct?
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
Who appoints the IVB and when?
The Duty Holder at the conception of the structure
Which of the following would produce a greater depth of field?
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
An ICCP system may produce over protection, this is bad because
It may cause embrittlement
The Near Zone of a Single Crystal ultrasonic probe Is
Used for lamination and thickness measurements
The ultrasonic Through Transmission Technique is used for?
Answer: None of these options
Weld inspection
Finding the depth of an internal defect
Flooded member detection
A diver carrying out FMD would use which of the following?
Answer: O.5MHz Ultrasonic probe
a. Iridium 192
b.Caesium 137
c.O.5MHz Ultrasonic probe
d.5MHz Ultrasonic probe
Proximity CP meters work only if?
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
In an ICCP sytem where would the dielectric shield be installed
Between the anode and the structure
In an ICCP system which materials are most commonly used for anodes
Platinum sheathed titaniun and lead/silver alloys
A retrofit anode Is to be installed, which of the following is necessary to make it work correctly
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
Sound waves in air will travel further when?
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.
Which of the following is an advantage of a twin crystal probe over a single crystal probe?
Good Near Zone resolution
Which of the following is a true statement with regards to brittle fracture
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
Which of the following is associated with Erosion Corrosion
Laminar flow
Crevice corrosion occurs because ?
Dissimilar oxygen concentrations
The Pourbaix Diagram displays which of these pairs of variables?
Potential and pH
AC current is more preferred for finding surface-breaking defects because?
The domains are agitated by the rapid change in direction
Altering the frequency of an ultrasonic probe will affect which of the following parameters?
The Wavelength
With regards to inspecting concrete structures: Variable Cover is what type
of defect?
A category ,construction defect
Dynamic Loading Is based on?
Normal Wave and wind spectrum
0.5 to 1.5MHz ultrasonic probes are used for testing which of the following?
Concrete
Which of these techniques cannot be used to determine the depth of a surface breaking defect?
Eddy current
a.ACPD
b.ACFM
c.Remedial Grinding
d.Eddy Current
