Magnetic particle testing level 1
A defect open to the surface produces an indication which is: A sharp and distinct B wide and indefinite C criss cross D high and fuzzy
A
A high velocity flow of wet method bath over surfaces of the specimen following removal of the magnetizing current may cause A a fine or weakly held indication to be washed away B no problems C particles to be splashed into eyes D none of the above
A
An electric current through a copper wire A creates a magnetic field around the wire B creates magnetic poles in the wire C magnetizes the wire D does not create a magnetic field
A
An electrical yoke produces A longitudinal field B a circular field C alternating fields D a swinging field
A
Demagnetization A may be accomplished by hearing a material above its curie point B is always necessary C can be performed only with AC D can be performed only with DC
A
Demagnetization A may be easy or difficult depending on the type of material B is easy for materials having a high coercive force C is always most difficult in materials retaining a high residual field D all of the above
A
If wet magnetic particle suspension is not uniform then The strength of an indication may vary, and the interpretation of the indication may be erroneous B the magnetic flux would not be uniform C greater mobility would be required D the part cannot be magnetized
A
Resistance to demagnetization: A greater in hard materials than soft materials B greater jn soft materials than hard materials C the same for both hard and soft materials D nonexistent
A
The major factor that determines the success of magnetic particle inspection is the A field strength B voltage on magnetizing coil C current through the coil D Time of magnetization
A
The permeability 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
A
The unit usually used to denote flux density is the A gauss B Henry C farad D ampere
A
The wet fluorescent magnetic particle inspection method is the same as the standard wet magnetic particle method with the exception of requirements for A black light B higher current C a different machine D type of current
A
What method provides greater sensitivity particularly in locating subsurface discontinuities A continuous B residual C circular D longitudinal
A
When magnetic material is placed into a coil, the magnetic lines of flux concentrate themselves in the material and: A create a longitudinal magnetic field B create a circular magnetic field C create a longitudinal circular field D have no effect
A
Which technique is the most sensitive A continuous B residual C interrupted D counter-current
A
Which type of current brings out surface indications most clearly A AC B DC C pulsed DC D DC with surge
A
Which type of current has a skin effect A AC B DC C half wave rectified D full wave rectified
A
Why should parts be cleaned after demagnetization A to assure that the magnetic particles are removed B to prevent false indications C to save the solids of the suspensions D to prevent cracking during heat treatment
A
when magnetizing a weld in two directions, and if the current used in the first direction is 750 amps and the current in the second direction is 400 amps, which of the following is true A the part should be checked to see if demagnetizing between operations is necessary B no precautions should be taken before the second operation C this is not a valid technique D there is no need to magnetize a weld in two directions
A
A coil around the part produces A circular field B longitudinal field C either a or b depending on the type of current applied D an intermittent field
B
A curve is sometimes drawn to show graphically the relation of the magnetizing force to the strength of the magnetic field produced in a certain material. This curve is known as the: A magnetic force curve B hysteresis loop C saturation curve D induction curve
B
A metal that is difficult to magnetize is said to have: A high permeability B low permeability C high reluctance D low retentivity
B
A part is adaptable to magnetic particle inspection if: A it is attached to an electrostatic field B the material is ferromagnetic C the material is nonferrous D the material is an electric conductor
B
Applying the theory of the right hand rule a longitudinal surface defect in a round bar is detected by current passing in a direction parallel to the direction of expected defects because A the current direction is in line with the defect B the magnetic field is at right angles to the defect C it makes no difference D the magnetic field is parallel to the defect
B
If a crack exists in a circular magnet, the attraction of magnetic particles to the crack is caused by: A coercive force B leakage field C Doppler effect D high reluctance
B
In circular magnetization, the magnetizing force is expressed in amperes. What term is used to express the magnetizing force in longitudinal magnetization A amperes B ampere turns C consequent poles D volts
B
In longitudinal magnetization the proper term for calculating magnetizing force is A amperes B ampere-turns C watts D ohms
B
Magnetic lines of force A travel in straight lines B form a closed loop C are randomly oriented D overlay in highly ferromagnetic materials
B
Magnetic particle inspection is a reliable method for detecting all of the following indications except A laps B deep seated cavities C cracks D seams
B
One advantage of using fluorescent particles is A that less equipment is required B the high speed of inspection C the cost D that they are more readily attracted
B
Residual magnetic particle inspection may be used when A parts are irregular in shape B parts are highly retentive C parts are highly stressed D evaluating continuous method indications
B
The amount of amperage used for magnetic particle inspection using the prod method is determined from the: A type of material B distance between the prods C diameter of the part D total length of the part
B
The flux within and surrounding a magnetized part or around a conductor carrying a current is known as: A saturation point B magnetic field C ferromagnetic D paramagnetic
B
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
The magnetism that remains in a piece of magnetizable material after the magnetizing force has been removed is called the: A tramp field B residual field C damped field D permanent field
B
The magnitude of the residual magnetic field in a specimen is dependent on: A l/d ratio B strength of the applied magnetizing force C right hand rule D left hand rule
B
The point at which the magnetism in a material cannot be increased even though the magnetizing force continues to increase is known as the: A salient pole B saturation point C residual point D remnant point
B
The strongest magnetic field in a coil is at the A outside edge B inside edge C center D end
B
The type of current that is best suited to detect surface discontinuities A DC B AC C pulsating DC D half wave
B
Using the residual test method, a number of parts are magnetized and laid on a rack prior to application of magnetic particles. Why is it important that they do not rub or touch each other A there is a possible loss of magnetic field B it may cause magnetic writing C it may damage the part D it makes parts hard to handle
B
What are the three causes of nonrelevant indications A lack of fusion, change of section thickness, grinding cracks B change if section thickness, very high amperage, drilled hole near surface C very high amperage, drilled hole near surface, blow holes D drilled holes near surface, very high amperage, lack of fusion
B
What equipment is used to determine whether a part has been demagnetized? A a magnet on the part B a field meter C a survey meter D careful observation for clinging magnetic particles
B
What rule describes the direction of current flow (+ to -) when lines of magnetic force surround a conductor? A the left hand rule B the right hand rule C the flux rule D the reluctance rule
B
When a magnetic field is induced in a part with prods spaces 152 mm apart the field is A solenoidal B circular C longitudinal D distorted trapezoidal
B
When inspecting a tabular product for surface defects along its length, the best type of field to use is a A longitudinal field B circular field C swinging field D yoke magnetization
B
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
Which residual field is most difficult to demagnetize A longitudinal B circular C vector D binodal
B
With current flowing from + to — in a coil, a longitudinal field is created. Which of the following may be used to establish the direction of the magnetic field A the left hand rule B the right hand rule C ohms law D There is no relevant law
B
A longitudinal surface crack in a circulatory magnetized part will cause A the magnetic field to die out B a decrease in permeability C a magnetic leakage field D a current flow
C
A magnetic particle build up from a discontinuity is strongest when the discontinuity is oriented A 180 degrees to the magnetic field B 45 degrees to the magnetic field C 90 degrees to the magnetic field D 90 degrees to the current flow
C
Coercive force A describes the means by which the magnetic particles are suspended in the liquid when using the wet methods B describes the magnetizing force used with the continuous method C represents the reverse magnetizing force necessary D is not a term used in magnetic particle testing
C
Fluorescent magnetic particle indications should be inspected under A fluorescent light B any light C black light D neon light
C
If a current is passed through an electrical conductor, what will surround the conductor? A an eddy current field B current C a magnetic field D a residual field
C
In a magnetic particle test, assuming that all of the following are in the same relative position in a small part, which would be the hardest to detect A a surface crack B a near surface crack C a scratch D a seam
C
Inspecting a part by magnetizing, removing the current flow, then applying the medium is called the: A continuous method B wet method C residual method D dry method
C
Magnetic flux lines which are parallel to a discontinuity produce A strong indications B weak indications C no indications D fuzzy indications
C
Magnetic particle is a nondestructive examination method used for A locating surface discontinuities B locating near surface discontinuities C both a and b D detecting material separation
C
Retentivity A represents the ability to induce magnetism in a ferromagnetic body by an outside magnetizing force B represents the ability of a material to resist the establishment of magnetic flux within it C represents the ability of a material to train a portion of the magnetic field set up in it after the magnetizing force has been removed D is not a term used in magnetic particle testing
C
Subsurface discontinuity indications usually appear: A sharp and distinct B sharp and wide C wide and fuzzy High and loosely held
C
The area of maximum induced field strength using a yoke is: A at the North Pole of the yoke B at the South Pole of the yoke C the area directly between the poles Ok the outside of pole pieces
C
The areas on a magnetized part from which the magnetic field is leaving or returning into the part are called: A salient points B defects C magnetic poles D nodes
C
The proper number of ampere turns for a given tests specimen is determined by A it's length B the material C both a and b D it's diameter
C
The strength of the magnetic field induced in a part is often referred to as A current density B voltage C flux density D retentivity
C
The strength of the wet suspension should be maintained at a given level because A a low level might give a weak indication B a high level mag give a heavy background C both a and b D none of the above
C
To detect lengthwise defects on the inside diameter of hollow parts, you should: A pass current through it B magnetize it with a coil C pass current through a central conductor D increase the amperage used
C
When preparing a bath, it is important to have the bath strength at a proper level because too many particles can result in A lowering of the test amperage B the need to increase the magnetizing current C the masking of indications D none of the above
C
When preparing an inspection bath, the amount of magnetic particles per gallon of fluid is called it's A measuring scale B particle number C strength or concentration D usable limits
C
When using the wet continuous method, the flow of suspension from the hose should be shut off A immediately after applying the current B immediately before applying the current C while the current is flowing D 30 seconds before applying the current
C
When using the wet particles in water suspension wetting agents are added to A prevent freezing B prevent corrosion of inspection equipment C ensure the proper wetting of the part D decrease the amount of water needed
C
Which form of magnetization is easiest to control in most parts? A longitudinal magnetization B permanent magnetism C circular magnetization D parallel magnetization
C
Which of the following will best define surface cracks A half wave rectified AC B DC C AC D surge current
C
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 prods D yokes
C
Why are magnetic particles available in different colors A for color contrast with the part surface B to enhance the detection of indications C both a and b D different colors are used with different magnetic flux values
C
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
A circular field may be induced into a specimen by A direct induction (head shot) B direct induction (prods) C central conductor D all of the above
D
A specimen may be demagnetized by A heat treatment above cutie temp B an AC coil C reversing DC fields D all of the above
D
False indications are caused by magnetic participles 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
D
The retentivity of a material describes A ease with with it can be magnetized B depth of the magnetic field in the part C length of time required to demagnetize it D the ability to retain the magnetic field
D
When there is absolutely no pattern or distribution of magnetic particles the possible cause is that A the material is nonmagnetic B the amperage setting is too low C no current is being applied D any of the above could be true
D
When using a dry magnetic particle powder, the proper way to apply it to the part is to: A forcibly apply it with air B roll the material in the container of powder C apply it from the bottom of the part D float the particles to the inspection surface as gently as possible
D
Which of the following can be magnetized A iron B nickel C cobalt D all of the above
D
Which of the following is an advantage of magnetic particle testing over pen testing A it can detect surface discontinuities with foreign material imbedded in them B it is faster on individual parts C it can detect near surface discontinuities D all of the above
D
Which of the following is the most effective method for the detection of extremely deep lying defects A dry residual method using DC with surge B wet continuous method using half-wave rectified current C wet residual method D dry continuous method using half wave rectified current with prods
D
Which statement is true when related to magnetic lines of force A they never cross B they are most dense at the likes of a magnet C they seek the oath of least resistance D all of the above
D
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 l C it is usually easier to handle the disassembled parts D all of the above
D
