Which defects can be commonly detected through radiographic testing?

Radiographic testing is a non-destructive testing method that uses X-rays or gamma rays to create images of the internal structure of an object. This technique is especially effective for detecting various types of internal defects that may not be visible through surface inspections.

The correct choice highlights that radiographic testing can identify cracks, voids, and porosity within a material. Cracks can be internal or external, and radiography allows for the detection of those that are hidden beneath the surface. Voids represent areas of missing material within a workpiece, which can lead to structural weaknesses, while porosity refers to tiny holes or voids within the material caused by trapped gases or irregularities during production. These defects can significantly affect the integrity and performance of the material or component, making their detection critical.

In contrast, the other choices focus on more limited or less relevant aspects of defect detection relevant to radiographic testing. For instance, detecting only surface cracks does not cover the full capability of radiography, which is designed to reveal internal issues. Similarly, external deformations and color variations do not typically present significant challenges for radiographic methods, as these methods focus on the internal structure rather than surface characteristics or changes in material coloration.