Final answer:
Resistance spot welding has several disadvantages including limitations on material thickness, requirement for clean and well-matched surfaces, electrode wear and maintenance, and unsuitability for non-conductive materials.
So option (E) is correct.
Step-by-step explanation:
Resistance spot welding, a technique commonly used in engineering, has some disadvantages:
Limited to certain material thicknesses: Resistance spot welding is most effective for materials with thicknesses between 0.5 mm and 3 mm. It becomes difficult to achieve proper welds with materials that are too thin or too thick.
Requires clean and well-matched surfaces: The surfaces being welded must be clean and free from any contaminants, such as oil or rust. Additionally, the materials being joined should have similar properties to ensure a strong bond.
Electrode wear and maintenance: During the spot welding process, electrodes come into contact with the materials being joined and can wear out over time. Regular maintenance and replacement of electrodes is necessary to maintain the quality of welds.
Not suitable for non-conductive materials: Resistance spot welding relies on the materials being conductive. Therefore, this method cannot be used to join non-conductive materials.