Magnetic Particle Testing Flashcards
Ferromagnetic material is:
a. strongly attracted by a magnet
b. capable of being magnetized
c. both A and B
d. not capable of being magnetized
c. both a and b
The retentivity of a material describes the:
a. ease with which it can be magnetized
b. depth of the magnetic field in the part
c. length of time required to demagnetize it.
d. ability to retain the magnetic field
d. ability to retain the magnetic field
Which of the following can be magnetized?
a. iron
b. nickel
c. cobalt
d. all of the above
d. all of the above
The magnetic field is strongest when the:
a. magnetizing voltage is flowing
b. magnetizing current is flowing
c. material exhibits high coercive forces
d. magnetizing current is not flowing
b. magnetizing current is flowing
The unit usually used to denote flux density is the:
a. gauss
b. henry
c. farad
d. ampere
a. gauss
Why is it preferable to disassemble parts before magnetic particle inspection?
a. disassembly makes all surface areas visible
b. interfaces will create leakage fields which may confuse the inspection
c. it is usually easier to handle the disassembled parts
d. all of the above
d. all of the above
False indications are caused by magnetic particles being held to the part by which of the following means?
a. gravity
b. mechanical
c. both a and b
d. none of the above
c. both a and b
Which of the following will produce circular magnetism?
a. passing current through a coil.
b. placing the test part in a solenoid
c. passing current through the prods
d. yokes
c. passing current through the prods
Which of the following is most often used for dry magnetic particle inspection?
a. full cycle direct current
b. half-wave rectified alternating current
c. high voltage, low amperage current.
d. direct current from electrolytic cells
b. half-wave rectified alternating current
Comparing parts that have been circularly magnetized and those that have been longitudinally magnetized, which retains the most objectionable residual field if not demagnetized?
a. longitudinal
b. circular
c. vectored
d. remnant
a. longitudinal
A rough forging that has received no further processing is magnetic particle tested. An indication is observed to run in every direction. It appears to extend deeply into the part and run perpendicular to the surface . It is very sharp. What is the probable identity of the indication?
a. forging burst
b. lap
c. flake
d. seam
a. forging burst
Discontinuities in plate, or strip caused by pipe, inclusions, or blowholes in the original ingot which, after rolling, are usually flat and parallel to the outside surface are called:
a. seams
b. laminations
c. cracks
d. laps
b. laminations
Half-wave rectified AC (HWDC) is used for detection of:
a. surface defects only
b. subsurface defects only
c. surface and subsurface defects
d. none of the above
c. surface and subsurface defects
The pattern of iron powder sprinkled on a paper placed over a bar magnet is called a:
a. field survey
b. magnetometer
c. magnetograph
d. fluxmeter
c. magnetograph
The lines of force that form a path around a crack in a ring magnet are called:
a. magnetic lines
b. leakage flux
c. field strength
d. longitudinal field
b. leakage flux
An example of a non-relevant indication classified as a magnetic irregularity rather than an actual discontinuity could be caused by:
a. a slag pocket
b. grinding cracks
c. an abrupt change in the hardness of the part
d. none of the above
c. an abrupt change in the hardness of the part
A magnetic discontinuity, which is a break in the magnetic uniformity of a part, is related to a sudden change in:
a. inductance
b. resistivity
c. capacitance
d. permeability
d. permeability
What happens to a magnetic material which it reaches its Curie temp?
a. it becomes paramagnetic
b. it becomes diamagnetic
c. it becomes non-magnetic
d. it becomes radioactive
c. it becomes non-magnetic