Which type of welding involves the use of heat generated by an electric arc?

The correct answer is associated with the process of generating heat through an electric arc, which is fundamental to several welding methods but is broadly defined as arc welding. This type of welding relies on an electric arc formed between an electrode and the base material, producing sufficient heat to melt the metal and create a strong joint once cooled.

Arc welding encompasses various specific techniques, including those identified in the question, like shielded metal arc welding and tungsten inert gas welding, both of which utilize an electric arc as part of their processes. This understanding emphasizes that while there are different methods under the arc welding umbrella, they all share the common principle of using electric arc-generated heat.

Other options such as shielded metal arc welding focus on a specific technique of arc welding, rather than the overarching category. Tungsten inert gas welding also falls under arc welding but is just one variant. Laser welding, on the other hand, utilizes a different energy source (lasers) rather than an electric arc, distinguishing it from arc welding processes. This highlights why the broad term "arc welding" best fits the question, capturing the essential characteristic of using electric arc-generated heat.