Non-Destructive Testing (NDT) Practice Test

Induction in eddy current inspection refers to the process of:

1. Heating a material to check for expansion

2. Measuring the thickness of a conductor

3. Generating electrical current within a conductor

4. Detecting surface anomalies using sound waves

The correct answer is: Generating electrical current within a conductor

Induction in eddy current inspection indeed refers to the process of generating electrical current within a conductor. This technique is based on the principles of electromagnetic induction, where an alternating magnetic field is created by a coil of wire. When this alternating magnetic field is brought near a conductive material, it induces eddy currents within the material. These eddy currents flow in circular paths and create their own magnetic fields. The strength and behavior of these induced currents are affected by various material properties, such as conductivity, permeability, and the presence of any defects. By measuring the characteristics of the eddy currents, inspectors can identify changes in material properties, which may indicate flaws or irregularities. This method is widely used in non-destructive testing because it allows for the detection of surface and near-surface defects without damaging the material being inspected, making it a valuable tool in quality control and safety assessments in various industries.