Magnetic Particle Inspection Level 1 Practice Exam

A yoke creates which type of magnetic field?

1. Radial

2. Circular

3. Longitudinal

4. Transverse

The correct answer is: Longitudinal

A yoke is a crucial component in magnetic particle inspection as it generates a magnetic field that is predominantly longitudinal. This means that the magnetic flux lines created by the yoke flow in a direction parallel to the length of the test object. In practice, this longitudinal magnetic field is effective for detecting surface and slightly subsurface discontinuities in ferromagnetic materials. The longitudinal magnetic field produced by a yoke enables the magnetic particles to be attracted to areas of potential leaks or defects, allowing for a clearer visualization of flaws when the magnetic particles are applied. This method is particularly useful because it aids in identifying cracks that run along the length of a material, which is common in structural components. Understanding the directionality and characteristics of the magnetic field created by a yoke is fundamental for effective application and interpretation within magnetic particle inspection. The other options, such as radial, circular, and transverse fields, do not accurately describe the configuration of the field produced by a yoke in the context of magnetic particle testing.