Which aspect is NOT affected by demagnetization?

Demagnetization primarily involves the reduction or elimination of the magnetic properties of a material. Therefore, any aspect directly related to its magnetic characteristics, such as magnetic performance or operational accuracy, would be affected by the process. The physical properties of a material, including its magnetic permeability, can change significantly due to demagnetization. The operational accuracy of instruments often hinges on their magnetic components, which may not function correctly if demagnetized.

In contrast, the appearance of the part typically refers to its visual characteristics, including color, texture, and surface finish. Demagnetization does not alter these visual aspects since it primarily focuses on magnetic properties rather than the physical appearance. Consequently, the correct response regarding which aspect is not affected by demagnetization is the appearance of the part, as this remains unchanged regardless of the material's magnetic state.