3.2u Mock Exam 2

Question 1

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

Answer 1

Passivation

Question 2

Which of the following is a Volumetric defect?

Answer 2

Answer: Undercut

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

3D
Fabrication Defect

Question 3

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

Answer 3

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

Question 4

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

Answer 4

ACFM

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

Question 5

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

Answer 5

Pitting Corrosion

Once Started: autocatalytic
Localized

Question 6

Iridlium 192 Is a Gamma Radiation source used for?

Answer 6

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.

Question 7

The Cathodic reaction is also known as?

Answer 7

Reduction

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

Question 8

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

Answer 8

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

Question 9

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

Answer 9

Half the amount of light entering the camera

Smaller aperature
Less light
Increase depth of field

Question 10

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

Answer 10

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

Question 11

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

Answer 11

Arc Blow

Question 12

Impingement is a consequence of?

Answer 12

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.

Question 13

Plain concrete is a description of?

Answer 13

Cement, aggregates and water

Question 14

Sea Squirts are which of the following?

Answer 14

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

Question 15

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

Answer 15

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.

Question 16

Which of the following statements 1s true?

Answer 16

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

Question 17

Which of these statements is true?

Answer 17

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

Question 18

Which of the following is an in-service defect?

Answer 18

Answer: Poor Repair

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

Question 19

Which statement, concerning welding defects, is true?

Answer 19

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

Question 20

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

Answer 20

Backscatter

Question 21

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

Answer 21

Transducer

Question 22

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

Answer 22

Copper/Nickel

Question 23

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

Answer 23

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

Question 24

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

Answer 24

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

Question 25

An Ultrasonic Digital Thickness Meter can be used to‘?

Answer 25

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

Question 26

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

Answer 26

30 Deg

Question 27

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

Answer 27

Answer: Magnesium a.Zinc b.Lead c.Aluminium d.Magnesium ## Footnote Magnesium is lower than Steel on the galvanic series

Question 28

In Ultrasonics, which of the following is correct?

Answer 28

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

Question 29

Who appoints the IVB and when?

Answer 29

The Duty Holder at the conception of the structure

Question 30

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

Answer 30

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

Question 31

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

Answer 31

It may cause embrittlement

Question 32

The Near Zone of a Single Crystal ultrasonic probe Is

Answer 32

Used for lamination and thickness measurements

Question 33

The ultrasonic Through Transmission Technique is used for?

Answer 33

Answer: None of these options Weld inspection Finding the depth of an internal defect Flooded member detection

Question 34

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

Answer 34

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

Question 35

Proximity CP meters work only if?

Answer 35

The positive side of the voltmeter is connected to the structure and a maximum 100 mm gap is maintained ## Footnote The Proximity meter is connected to the negative The ICCP anode is connected to the positive terminal

Question 36

In an ICCP sytem where would the dielectric shield be installed

Answer 36

Between the anode and the structure

Question 37

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

Answer 37

Platinum sheathed titaniun and lead/silver alloys

Question 38

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

Answer 38

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

Question 39

Sound waves in air will travel further when?

Answer 39

The wavelength is longer ## Footnote 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.

Question 40

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

Answer 40

Good Near Zone resolution

Question 41

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

Answer 41

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

Question 42

Which of the following is associated with Erosion Corrosion

Answer 42

Laminar flow

Question 43

Crevice corrosion occurs because ?

Answer 43

Dissimilar oxygen concentrations

Question 44

The Pourbaix Diagram displays which of these pairs of variables?

Answer 44

Potential and pH

Question 45

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

Answer 45

The domains are agitated by the rapid change in direction

Question 46

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

Answer 46

The Wavelength

Question 47

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

Answer 47

A category ,construction defect

Question 48

Dynamic Loading Is based on?

Answer 48

Normal Wave and wind spectrum

Question 49

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

Answer 49

Concrete

Question 50

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

Answer 50

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