Magnetic Particle Inspection Level 2 Practice Exam

If particles are drawn to a surface site due to a magnetic leakage field indicating an unacceptable condition, what is it called?

1. A discontinuity

2. A defect

3. A non-relevant indication

4. All of the above

The correct answer is: A defect

The correct term for particles being attracted to a surface site due to a magnetic leakage field indicating an unacceptable condition is referred to as a defect. In the context of Magnetic Particle Inspection (MPI), defects are irregularities or failures in the material that compromise its integrity or performance. These can include cracks, voids, or inclusions that create a disturbance in the magnetic field, leading to the accumulation of magnetic particles at those points. While "discontinuity" is also a relevant term used to describe an interruption in the physical structure of a material, not all discontinuities signify a defect. Discontinuities can include both acceptable and unacceptable conditions. On the other hand, "non-relevant indication" refers to signals seen in the inspection that do not represent actual defects, such as surface roughness or irrelevant geometric features. Thus, a defect specifically points to those conditions that should be addressed due to their detrimental impact on the material’s functionality, which is why this term is the most appropriate answer for the given scenario.