The radioisotope used in industrial radiography for the rapid checking of faults in welds and casting is

The radioisotope used in industrial radiography for the rapid checking of faults in welds and casting is cobalt-60 (Co-60). Cobalt-60 is a gamma-emitting isotope that produces a very penetrating form of radiation, which makes it ideal for industrial radiography. In this process, the cobalt-60 source is placed on one side of the object being examined, and a special film is placed on the other side. The gamma rays penetrate the object and are absorbed by the film, creating an image that reveals any faults or defects in the material. It is important to note that other radioisotopes such as carbon-14 (C-14), phosphorus-32 (P-32), and iodine-131 (I-131) are not commonly used in industrial radiography due to their lower penetrative power and shorter half-life.