Which characteristic describes non-destructive testing?

• A. It permanently alters the sample to reveal defects
• B. It allows the sample to be used again and can check for internal damage
• C. It requires disassembly of the component
• D. It cannot detect internal flaws

Answer: (B)

Non-destructive testing focuses on evaluating a part’s condition without causing damage, so the item can still be used after inspection and you can look for flaws inside it. The statement that best fits is that the sample can be used again and can check for internal damage, because NDT methods like ultrasound, radiography, and eddy current testing reveal subsurface flaws without altering the part. The other ideas describe destructive or invasive approaches: permanently changing the sample, or requiring disassembly, which either damages the part or goes beyond non-destructive methods. And claiming that internal flaws can’t be detected is incorrect because many NDT techniques are specifically designed to find hidden defects.