The pattern for an inclusion in magnetic particle inspection is

The pattern for an inclusion in magnetic particle inspection is

• A. a single line
• B. a fernlike pattern
• C. parallel lines
• D. a circular ring

Answer: (C)

In magnetic particle inspection, the way a defect disturbs the magnetic flux shows up as a surface pattern. An inclusion is an elongated foreign material embedded in the metal, so it disrupts the magnetic circuit along its length. When you magnetize the part, leakage fields form along the sides of that elongated inclusion, producing several indications that run in the same direction. That creates parallel lines on the surface rather than a single isolated mark or a branched, fernlike cluster, and not a circular ring. So parallel lines are the telltale pattern for an inclusion because the defect’s shape guides the flux leakage into a row of aligned indications, reflecting the lengthwise disturbance of the magnetic path.

In magnetic particle inspection, the way a defect disturbs the magnetic flux shows up as a surface pattern. An inclusion is an elongated foreign material embedded in the metal, so it disrupts the magnetic circuit along its length. When you magnetize the part, leakage fields form along the sides of that elongated inclusion, producing several indications that run in the same direction. That creates parallel lines on the surface rather than a single isolated mark or a branched, fernlike cluster, and not a circular ring.

So parallel lines are the telltale pattern for an inclusion because the defect’s shape guides the flux leakage into a row of aligned indications, reflecting the lengthwise disturbance of the magnetic path.