Final answer:
A crack perpendicular to the length of the weld is termed a transverse crack, which is essential to identify corrective measures.
Step-by-step explanation:
A crack perpendicular to the length of the weld is called a transverse crack. This type of crack is associated with stress that occurs across the weld axis, which can be due to several factors including thermal stresses, weld metal shrinkage, or improper welding technique. Understanding the nature of the crack is essential for identifying the underlying cause and for developing appropriate corrective measures.