ASNT Magnetic Particle Testing - Level I & II Practice Questions — 10 Free (2026)

What distinguishes a defect from a discontinuity in MT terminology?

• A. A defect means any break in a part's ordinary physical makeup, whether or not service is affected
• B. The two terms are interchangeable
• C. A discontinuity is severe enough to warrant rejection, while a defect may be acceptable
• D. A defect is a discontinuity severe enough to warrant rejection of the part ✓
• E. A defect is always subsurface

A discontinuity is any interruption in normal structure and may be harmless, while the term defect is reserved for a discontinuity whose size or effect on service justifies rejecting the part. Every defect is a discontinuity, but not every discontinuity is a defect. ASNT MT Level II Presentation, Relevant Indications - Terminology

With the headstocks set for maximum output and nothing clamped between the contacts, a technician energizes the current and sees the ammeter needle move. What does ASTM E709 say this indicates?

• A. The meter zero is off and the check should simply be repeated after the meter face is tapped and the range switch cycled
• B. Normal transformer inrush; nothing is wrong
• C. An internal short circuit exists and the unit must be repaired before further use ✓
• D. The quick break circuit has operated
• E. Residual magnetism is stored in the headstocks

With no conductor bridging the contacts there is no legitimate current path, so any deflection means current is leaking inside the machine. The fault must be corrected before the unit is returned to service. ASTM E709 Section 20.3.5

An aerospace prime contractor needs a document that can be cited on an engineering drawing to impose enforceable minimum requirements for wet fluorescent magnetic particle testing. Why is ASTM E1444 chosen over ASTM E709?

• A. E709 has been withdrawn by ASTM and can no longer be referenced
• B. E709 applies only to weld examinations in the aerospace sector
• C. E1444 covers dry visible particles as well as wet fluorescent ones, while E709 is restricted to the wet fluorescent method and therefore cannot be applied to aerospace hardware examined under contract
• D. E1444 contains detailed step-by-step instructions for operators
• E. E1444 states mandatory minimum requirements and is written so it can be invoked on a drawing, specification, or contract, while E709 serves only as a nonmandatory tutorial guide ✓

E1444 is a practice carrying binding requirements intended to be specified on drawings and contracts, though a facility applying it still has to add its own detailed written procedure. E709 remains a guide that may accompany it as tutorial material. ASTM E1444 Section 1.1 and 4.2

A generator data sheet lists a rated current Ir of 3000 A with no further qualification. Per ISO 9934-3, this rating is understood as the maximum current the generator can deliver:

• A. at a duty cycle of 10 percent with a current ON time of 5 s ✓
• B. at whatever duty cycle the purchaser later selects during production testing of the largest component in the order
• C. for a single half-cycle only
• D. continuously without any time limit
• E. into a short circuit at full open circuit voltage

Unless the supplier states otherwise, the rating is tied to the default operating pattern of one tenth duty cycle and five-second shots, so continuous delivery at the rated value cannot be assumed. ISO 9934-3 Section 4.2.1

Under Article 7, how many times must each area be examined, and how do the examinations relate?

• A. Three times, turning the flux by about sixty degrees between runs
• B. Once only, using whichever technique raises the strongest field
• C. Twice, both runs using flux in the same direction for repeatability
• D. As many times as needed until no further indications appear on the part
• E. Twice, the flux in the second run roughly at right angles to the first ✓

Sensitivity peaks for discontinuities lying across the flux, so each area gets two separate runs with the second field turned roughly perpendicular; the technique itself may differ between them. ASME V Article 7 T-772

A component arrives for magnetic particle testing carrying an unbroken adherent paint layer measured at about 40 microns thick. Under the ISO 9934-1 surface preparation rules, how should the technician proceed?

• A. Use only dry powder because inks cannot wet painted surfaces, whichever instrument passed the daily check
• B. Strip all of the paint before any testing
• C. Demonstrate sensitivity on a reference piece first, because any coating thicker than 25 microns automatically invalidates the standard technique until verified
• D. Double the magnetizing current to compensate for the lift-off created by the coating
• E. Test through the coating, since nonferromagnetic layers up to roughly 50 microns do not normally reduce detection sensitivity ✓

Adherent nonferromagnetic layers of up to about 50 microns normally leave sensitivity unimpaired, so the part may be tested as received; verification only becomes mandatory when the coating is thicker than that. ISO 9934-1:2016 Clause 7

A procedure writer must name the material property that determines whether enough magnetism remains after the current stops for the residual technique to work. Per ASTM E1316, that property is:

• A. magnetic saturation flux density
• B. hysteresis
• C. coercive force
• D. retentivity ✓
• E. permeability

Retentivity names a material's capacity to hold part of the applied field once the magnetizing force stops acting; permeability instead describes how readily the material magnetizes while that force is present. ASTM E1316 Section G - MT Terms, definition of retentivity

What are the essential features of the type 1 reference block used for performance testing of detection media under ISO 9934-2?

• A. A hollow cylinder that is magnetized by an encircling coil before every use
• B. A permanently magnetized hardened steel disc containing both fine stress-corrosion cracks and coarser grinding cracks ✓
• C. A chrome-plated panel carrying five artificial star cracks
• D. Two mild steel bars separated by a thin aluminium shim and energized by adjustable permanent magnets so the field reads 100 A/m at the number 4 graduation
• E. A ring specimen with drilled subsurface holes located at increasing depths

The type 1 block is a disc of hardened tool steel with two crack families, one produced by grinding and one by stress corrosion, and it is given a permanent magnetization through a central conductor so media can be compared visually. ISO 9934-2:2015 Annex B.1

A purchase order invokes ISO 23278 acceptance level 2X. What does the X suffix change compared with plain level 2?

• A. Grouped indications become acceptable if ground flush
• B. The surface must be dressed to a fine machined finish before the test begins
• C. The nonlinear limit tightens from 3 mm down to 2 mm while linear indications continue to be assessed against the ordinary level 2 limit of 3 mm exactly as tabulated
• D. Every detected linear indication must be assessed against the level 1 size limit ✓
• E. Nothing; the X merely marks in-service use

Adding the suffix to level 2 or 3 forces all linear indications found to be judged against the tightest tabulated length limit, while cautioning that indications smaller than the base level's detection capability may simply not be found. ISO 23278:2015 Table 1 footnote a

Unless an application standard states otherwise, which magnetizing equipment does ISO 17638 permit for weld testing without any special agreement?

• A. Alternating current devices such as yokes, prod current flow units, and coil, adjacent-conductor or threading-conductor arrangements ✓
• B. Residual method equipment with capacitor discharge units
• C. Any equipment that can lift a 4.5 kg steel plate
• D. DC electromagnets, provided the operator verifies the field with a shim indicator before each shot and records the result in the final test report
• E. Permanent magnets of any strength

The default equipment list is entirely AC based because alternating current gives the best surface sensitivity; rectified-current electromagnets and permanent magnets need to be agreed between the parties when the work is ordered. ISO 17638:2016 Section 5.5.1