MPI Flashcards
(34 cards)
1
Q
- an object that has the ability to
strongly attract iron and other
magnetic materials is termed
a magnetic
b ferromagnetic
c diamagnetic
d magnetisable
A
b
2
Q
- which of the following are correct
a unlike magnetic poles attract one another
b unlike magnetic poles repel one another
c like magnetic poles attract one another
d like magnetic poles invert one another
A
a
3
Q
- what symbol is used to denote
magnetising force
a H
b B
c Z
d Mg
A
a
4
Q
4. what is the SI unit for magnetising force: a oersted b coulomb c amps per metre d gauss
A
c
5
Q
5 what is the term given to the resistance of a material to a magnetising force a resistance b perspicacity c reluctance d potential
A
c
6
Q
6 what is the unit of magnetic flux: a oersted b maxwell c gauss d tesla
A
d
7
Q
7 what are the lines of force that jump
the gap formed by a crack called:
a vector fields
b resultant force
c flux leakage
d hunters
A
c
8
Q
8 what symbol denotes flux density: a H b B c Z d Fd
A
b
9
Q
9 what is the SI unit for flux density: a gauss b Kg/m2 c tesla d oersted
A
c
10
Q
10 materials that are repelled by a magnetic field such as bismuth are called: a diamagnetic b paramagnetic c antimagnetic d ferromagnetic
A
a
11
Q
11 what is the formula for caluculating permeability: a P = BH b µ = B/H c µ = H/B d µ = HB
A
b
12
Q
12 high permeability materials will have: a high retentivity b high residual magnatism c continually aligned domain d low retentivity
A
d
13
Q
13 what is the reversing magnetising force required to remove residual magnetism from a material called: a coercive force b hysteresis loop c residual potential d nega-residual magnetisation
A
a
14
Q
14 which of the following will require the greatest coercive force: a high carbon steel b soft iron c perspex d all the same
A
a
15
Q
15 which of the following methods of producing magnetic flux is not used underwater: a prods b permanent magnets c parallel closed loop conductor d threader bar
A
d
16
Q
16 which of the following is generally considered to be the most consistent method for producing sufficient
magnetic flux underwater:
a prods
b threader bars
c permanent magnets
d parallel closed loop conductors
A
d
17
Q
17. which of the following configurations can be used with parallel loops: a kettle element b free pole c coil d all of the above
A
a
18
Q
18 which of the following field indicators may be used underwater: a burmah castrol strip b gaussmeter c berthold penetrameter d all of the above
A
d
19
Q
19 what flux density is required in the testing area for MPI: a more than 1 tesla b more than 0.72 gauss c more than 365 nanometers d more that 1.44 gauss
A
a
20
Q
20 which of the following is best suited to locating surface defects: a AC b DC c HWAC d full wave 3 phase AC
A
a
21
Q
21 what is the best method for demagnetizing an article:
a reversing it in the magnetic field
b reversing the current through the coil
c reversing the coil around the article
d applying an alternating magnetic field and
reduce to zero
A
d
22
Q
22 when using DC for demagnetization how often should the current be reversed: a 50 times per second b once a second c every half second d it should only be reversed once
A
b
23
Q
23 for use in MPI what pull must permanent and electromagnets have: a more that 18 Kg b more than 45 Kg c more than 10.5 Kg d more than 28 Kg
A
a
24
Q
24 what is the optimum orientation of a defect with relation to the lines of magnetic force: a 45o b 0o - parallel c 90o d 45o - 90o
A
c
25
```
25 what are the spacing limits for prods:
a 0 - 10 cm
b 5 - 10 cm
c 0 - 20 cm
d 15 - 30 cm
```
d
26
```
26 for surface wet ink application what inks may be used:
a black
b red
c fluorescent
d all of the above
```
d
27
```
27 what is the maximum solid content for fluorescent ink above water:
a not greater than 0.35% by volume
b not greater than 10% by weight
c not greater than 0.35% by weight
d not greater than 10% by volume
```
a
28
```
28 when checking the U/V light intensity
at a distance of 40 cm what is the
minimum requirement:
a 10 lux
b 50 lux
c 150 lux
d 210 lux
```
c
29
```
29 what wavelength ultra violet light must be emitted during testing:
a less than 320 nanometers
b greater than 365 nanometers
c less than 365 nanometers
d greater than 320 nanometers
```
b
30
```
30 how long does it take for the UV light to reach full intensity:
a 30 seconds
b 1 minute
c 15 minutes
d 1 hour in seawater
```
c
31
```
31 longitudinal defects in a lonitudinal weld can be readily detected by:
a longitudinal magnetizm
b a circumfrential magnetic field
c a coil at 90o to the weld
d none of the above
```
b
32
```
32 the ease of magnetism is called:
a conductor
b coercive force
c resistance
d permeability
```
d
33
```
33 UV light emits wavelengths of between:
a 365 - 400 angstroms
b 365 - 400 nano meters
c 1000 - 2000 angstroms
d 500 - 600 nanometers
```
b
34
```
34 magnetic ink composition is mainly:
a iron oxide
b ferric chloride
c coarse iron filings
d fine iron filings
```
d
