Which isotopes may be used for performing radiography?

The use of isotopes for radiography is primarily aimed at non-destructive testing and inspection of materials. Among the listed options, Iridium-192 and Cobalt-60 are commonly employed isotopes in industrial radiography due to their suitable energy levels and penetration capabilities. They produce gamma radiation, which is effective for exposing radiographic films, allowing inspectors to detect imperfections within materials such as welds or castings.

X-ray machines are also included in this option as they serve a similar purpose in producing high-energy X-rays, which can effectively penetrate materials. This combination of isotopes and X-ray technology makes the chosen option appropriate for radiographic inspection, emphasizing the practical applications of both radioactive isotopes and radiography equipment in the field of welding and materials inspection.

In contrast, the other options include isotopes that are either not typically used in industrial radiography or don’t provide the optimal radiation characteristics needed for material inspection.