X-rays can be used to: 1. inspect welded joints between two metal parts of a machine. 2. study structure of crystals. Select the answer using the code given below:

X-rays are widely utilized in both industrial and scientific applications. Statement 1 is correct as X-rays are a primary tool in industrial radiography for the non-destructive testing (NDT) of welds. They penetrate metal parts to create contrast images that reveal internal defects such as cracks, porosity, and incomplete penetration in welded joints. Statement 2 is also correct; X-ray diffraction, discovered in 1912, is a fundamental technique used to study the internal structure and imperfections of crystals. By analyzing the diffraction patterns produced when X-rays interact with a crystal lattice, scientists can determine the arrangement of atoms within the material. Consequently, X-rays serve as a critical diagnostic tool for ensuring the structural integrity of machinery and for advancing materials science through crystallography.