Answer :
Final answer:
The correct answer is projection welding, which uses projections on one piece to focus heat in specific areas to join metal parts.
Explanation:
The type of welding in which a projection is forced into a pool of molten metal, which solidifies around it, is known as projection welding. This process is used to join metal surfaces by melting a small area with heat generated from an electrical current. Unlike spot welding, which joins materials at a single point, projection welding can join at multiple points or along a seam. It's also different from arc welding and MIG welding, where a filler metal is used to create the bond between two separate pieces of metal. Projection welding relies on raised sections, or projections, on at least one of the pieces being welded to concentrate the welding current in a small area.
