Non-Destructive Testing (NDT) Practice Test

Magnetic particle inspection can be considered a combination of which two NDT methods?

1. Magnetic flux leakage and visual testing

2. Radiographic testing and ultrasonic testing

3. Liquid penetrant testing and eddy current testing

4. Visual testing and acoustic emission testing

The correct answer is: Magnetic flux leakage and visual testing

Magnetic particle inspection combines the principles of magnetic flux leakage and visual testing. This method relies on the magnetic properties of ferromagnetic materials to detect surface and near-surface discontinuities. In this process, a magnetic field is applied to the test object, and if there are any flaws, they disrupt the magnetic field and create a leakage field. Magnetic particles, which can be dry or suspended in a liquid carrier, are then applied to the surface. The particles will gather around the area of the detected discontinuity, making it visible to the inspector. This is where the aspect of visual testing comes into play, as the gathered particles visually indicate the presence and location of defects. The other options do not appropriately represent the combination of methods. For instance, radiographic testing and ultrasonic testing are separate NDT techniques that rely on different principles, such as X-ray or sound wave propagation, to find flaws. Similarly, liquid penetrant testing involves a dye or fluorescent penetrant, whereas eddy current testing relies on electromagnetic induction, neither of which relates directly to the magnetic properties utilized in magnetic particle inspection. Visual testing and acoustic emission testing also involve different detection mechanisms not related to the fundamentals of magnetic particle inspection.