ET ASNT Level I 2025 – 400 Free Practice Questions to Pass the Exam

The correct answer is that encircling coils are commonly used to test rods, tubes, and wire. This method is particularly effective for evaluating the integrity of cylindrical objects, as the coil encircles the entire item being tested. This configuration enhances the ability to detect surface and near-surface flaws by inducing eddy currents in the material. The electromagnetic field generated by the encircling coil interacts with the conductive material, allowing for effective analysis of its properties and any potential defects.

While plate, sheets, and metallized foil can also be tested using different methods, they are not typically subjected to testing with encircling coils in the same manner as cylindrical products. Each testing method has its own specific application based on the geometry and type of the material being examined. Thus, rods, tubes, and wire are the most relevant items commonly associated with encircling coil testing.